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So another bit of fun. We're approaching 500k on the 240 and I suppose odd problems are to be expected. Today's adventure appears to be ignition related. Smooth running EXCEPT for the occasional stumble.
New:
COIL - BOSCH OEM
COIL harness spade connectors
CAP
ROTOR
POWER STAGE - BOSCH OEM
PLUG WIRES
PLUGS - NGK BPR6ES
When she's running at highway speed, it's just super smooth EXCEPT for what feels like random misfire, which can cluster or go for a few minutes without manifesting.
No lag or symptoms of fuel delivery issues.
No codes.
No correlation between heat/humidity and missing.
No worsening under load, but you do notice it more because the miss hits when you're needing acceleration.
Ideas?
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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I would check the radio suppressor relay its on the inner guard at the top for a dry solder joint and i would clean all negative/earth contacts on car.
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Do you have a tach? If so, what does it do on misfire. If it twitches in sync with the misfire, suspect the CPS.
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No tach. But thank you :-)
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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I had the same problem as you described. Turned out to be water sitting in the banjo hose between airbox and AMM and a disturbed air inlet to the inlet filter housing, allowing water into the air filter box when driving through rain. What's your filter element like?
Another source of troubles (especially at nearly 500k, like mine) are old sensors with bigger fluctuations in their signals as they get old. Worth checking especially if they're in since the car was new. This sometimes throws up error codes but not always.
Hope this helps. Best of luck.
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I had a similar stumble that wound up being a failing AMM.
Dan
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Another AMM from Advance. Ran 100 miles and died in a drive thru.
I can't imagine what could be killing them, unless these two have just been garbage. Air box is screwed closed (cold inlet only).
I sat in some traffic and it started to surge. Getting going helped. Surging diminished and then it ran smoothly again.
Then I stopped for a burger and that was that.
Ideas?
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Update. Another ugly, uncapped (!) remain AMM came in to Advance. My wife pointed out the horrible condition, and the store manager said he was embarrassed to sell it to me, so he didn't. Got my money back and ordered from FCP.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Got a new (reman) AMM from a reputable source.
Another week goes by. Flawless operation on street and highway and.... Sudden Fail. On the freeway.
So I swapped it I the breakdown lane (that's what it's there for, after all, right?) with my "known bad but not that bad" AMM, got home, put the new recently failed one in and... it ran like a top.
Underhood temperature problem? I have the tropical fan clutch and no gauge indications of coolant overtemp at all.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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And even though traffic has fallen to zero, here's another update.
Had another phantom AMM fail in hot weather. This time I found...
A split in the relatively new breather box.
Vacuum/PCV leakage around the dipstick base.
New (old, but OEM) box.
JB Weld.
It has never run more smoothly than it did today. OF course, until it gets some reliable operation going, I'm nervous driving, expecting the same symptom with any bubble. It gets better. Or, it better.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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I guess it's possible!
If air came up the flame trap hose and ENTERING into the port on the right side of the throttle body,
That is behind the AMM and alone would upset any mixture control.
This is a self tuning engine system and work pretty fast to correct things.
Maybe the opening got bad enough?
I will cross my fingers for you on this one!
Phil
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Still running more smoothly than ever in the 12 years I've owned it.
What an ordeal.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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...Until she didn't.
Classic AMM fail symptom - smooth run until throttle input change - only no change with swap.
Something wiring...
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Oh my! I was afraid you were gonna be back on here with the same problem.
I think you are correct that it's a wiring or component in the system. The flame trap, air leak idea, would have been a more steady or constant performance problem and very harsh at idle.
This appears to be a multiple speed and load related issue. As you put it, random.
I noticed in the profile that you are in Florida so it's not like you are subjecting the engine to any great load of pulling hills up in the Appalachians.
An Ignition System with weak components will miss fire under those conditions or moisture.
Even if the plugs are gapped wrong they will misfire due to the extra heavy fuel mixture.
I prefer Bosch part # 7900, for longevity but those new NGK's should be fine. Watch the gaps though!
I think you have combed though the other avenues of the harness and the power stage behind the battery.
We tried to rule out that it gets better after ever movement made around there. It still floats around in my head though.
These are complex enough issues not to be a steady broken wire as well, but sea air moisture can be a issue.
I want to move elsewhere to help rule out another thought that's giving me bad vibes!
Do you drive to the coast a lot or does your car stay outside near a body of water?
Park over damp ground/grass instead of concrete?
Do your know if the car has ever been caught in deep water or had a windshield on the passenger side?
I am trying to find out if either the ECU or the ICU have been wet.
I think I would yank both connectors to them, with the battery disconnected for safety, and inspect for corrosion on the clips inside and the pins. Use a bright light and a mirror if needed.
Spray everthing with a light coat of LPS 1 or coat with a thin smear of dielectric grease.
Also pull the injector clips off the injectors and treat the same.
Twist the mounting bolts of each component a few turns and reseat them to break any ground corrosion to the body of the car.
I think the ICU is only clipped on, so look for any adjacent grounding wires from the harness to the body. There should be one from the fuel relay on the firewall as well.
Past doing all of this, if it still acts up, my vibes are pointing to an ECU issue. This is because they are a more complex device than the ICU. The ICU takes orders from the ECU.
With that logic I have to ask, How old is the Crank Position Sensor?
I have been dismissing it because, when it's bad or going bad, starting is one of its larger symptoms.
I am sure we are both right the random gremlin is electrical making a mechanical good engine and fuel system act up.
Electronics don't always breakdown with a flat "OFF!" They go out with no more of an attitude!
Sometimes, they like doing a FIZZLE routine before they die.
Part of which, gives us the frazzle and dazzle of promoting our spastic fits!
Cars, don't you lov'em anyway!
We usually get one of those first and then we get married, go figure? (:-)
Phil
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No sea air.
No flooding.
CPS is probably pretty old. I haven't replaced it and I've had the car for 11 years. But never a problem at start and no random death typical of that fail.
What gets me is that although I started out chasing the intermittent stumble, it's now that classic AMM fail symptom when it goes. Running at highway speed and you feel the change. Throttle input leads to heavy bogging and then, soon after, lope and stall if for some reason highway speed is not maintained. No codes, no CEL.
And always the same thing, as if the AMM had failed. No other symptoms.
I'm going to look next at the temp sensor and the TPS. And every wire and connector, having already touched every hose, nipple and clamp.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Is this car a LH 3.1 with a variable resistance throttle position switch?
I replaced one of those one a 2000 Dodge truck that had random fast idle issues plus a random CEL a few years back. It was a chase for me! They also have distributor cap moisture issues with too big of a vent hole as I remember.
The ECU does not like misfires and the whole world evolves around the TPS.
Between those two things you mentioned one would be enough!
You can ohm the TPS for clicks or a very smooth transition of reading.
But with the CPS, that's another story!
My neighbor, maintained a fleet of trucks and had a Portuguese worker that was bad at stripping threads on various brass fittings! He would cross them up.
Everytime he heard him talking to himself, out loud, he knew he was just about to stripped another or it was too late!
He would always say, " Its just like my Maria, she gotta go!"
Thanks for pondering my theories on your car. Information of the past history can be our friend.
This might help as 11 years is a bit of time let alone what was before?
I'll cross my fingers and eyes if would help!
Phil
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I've continued to chase the phantom lag.
The symptoms are EXACTLY those of a failed AMM.
I mean EXACTLY.
I did find some things last go-round.
Brittle valve cover gasket. Fixed.
Stripped ground bolt behind the battery. Fixed.
The problem disappeared for two weeks, then came back toward the end of a hot two-hour journey. Then went away. Then came back today at the end of a hot commute.
So today here's ALL I did.
Pulled Fuse 6.
Ran great after ECU reset.
I guess I have a flaky computer. Sigh.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Another thousand-odd miles with no issues, and then it happened again. Weird. But cooling the AMM down to ambient fixed the problem.
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I don't know what to say about the recurring random misfire so far apart in miles?
We have or I talked about it seems that every time you mess around in that corner it changes?
Now you cooled the AMM down and its fixed. How did you cool it? Bottle Water or just let it sit for an extra Perrier of time? (:-)
I know electronics can be "temperamental" when overheated. You are adding a new dimension to idea of temperature relationships.
When it down to this happening on a regular basis, you just have to give into it.
The AMM does control mixture up to a certain point in the program. A lean mixture under a hotter thin air condition can cause misfiring.
It's possible that either the electronics is changing the calibration or it's plain out of calibration at this point or range of operation.
The earlier AMM bodies, that I am familiar with, are made of aluminum on the inside. The air flow through the unit cools the electronics like a heat sink.
Do you have the air cleaner thermostat removed and the side door to the heat pipe blocked shut?
I replaced the wax thermostat with a 5/8" square block of wood or plastic to permanently shove that door over.
Either that or remove the heat pipe, that runs from the exhaust manifold stove shroud, to the air cleaner to induce more cool fresh air into a "clean" air filter and its housing side.
The radiator runs right down beside the housing. It can reach 150 degrees in there during stops, easily.
The only other thing I can suggest is to wrap a heat shield material around the outsides of the AMM.
Aluminum foil can do the trick short term.
It's hard to believe that any radiant heat is traveling that far except from the radiator or the high side line of the A/C compressor.
The exhaust side of the car would be another story. That is probably why you never see them mounted in-line with things like that on any car!
I think over this long period of time you have probably ruled out the harness and connections so going with a bad AMM cannot be closed out of this picture.
With rebuilds the way they are, I would try to push the "heat question" out of the picture before springing for a new Bosch unit, any of their rebuilds or rebuilders unless their licensed under them.
Know their warranty clauses!
Other choices are junkyards. For $35 you roll the dice that someone else paid up front for one! If there are lots in the yards around you, you can exchange just as well?
Dan Murino posts and Art Benstein had a weekend together working over similar issues.
That had me second guessing myself to which one of the two I was following, mentally, over the past few weeks.
Dan has posted that it may have been his AMM after all. I think that was an idle and CEL light issue?
They also changed around the O2 sensor, which is two out of three possibles, short of the ECU being flaky!
Anyway that's the best thoughts, I can suggest, if my car was pulling the antics like these!
Phil
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Well, the next thing I did was replace the cat. I know it was bad; I'm wondering if it perhaps got hot and futzed with O2 readings. Maybe my cooling off the AMM just happened at the same time as the cat was cooling.
Ffffffffffff I really don't know.
So I've been driving a friend's Infiniti i30 for a week or so. Last week... Alternator fail!
So my friend got free labor. 2 hrs to swap an Infiniti alternator. Wow.
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I can't make any conclusions about the cat messing with a random miss fire.
I see your point that the O2 sensor might change mixtures while underway but so might the hot AMM.
Usually a plugged cat with cause an overall down grade of power due to lack of exhaust gas flow.
As far as two Hours to change out the alternator, on that car may not be so bad, as could have been an Infiniti! (:-)
Phil
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Note that the problem (d)evolved/mutated from the random misfire condition to the "dead after two hours" condition.
I would post a status update, but you all know what happens when you do. What the mecha gods do...
So let's just list her condition as "guarded" for now, the cat having been swapped and several trips having been undertaken.
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Did it again. Came off a 90 minute freeway run in 90+ heat. Lags on throttle input, surges at idle almost like there's a big vacuum leak, and I swear it seems like the brake pedal is hard, just like when the brake assist check valve fails. Weird. I know she'll run just fine in an hour, once she's cooled down. I'm going to replace every sensor on that engine one at a time, starting with ECT, and every hose.
Not like anyone's reading anymore anyway. This has become my personal 500k fail diary.
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When it does not start do you have both spark and fuel?
Dan
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Dear Brick Diary:
It's gotta be the booster. Things have cooled off and pedal travel and feel are back to normal and that hiss it's always had under the dash happens. I don't think it was doing that when I was babying her home all touchy.
I guess the booster can't take the heat anymore.
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rofl
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Well, I just got through reading all your posts, skimming Phil's, and wondering two things:
(1) still, when this craps out you have no OBD indications?
(2) could not determine you ever replaced the CPS
I would like you to tell me if you have the PAL fuses at the battery (late production 93) and whether you see any discoloration at the fuseholder (PAL fuse or fuse 6 if no PAL fuses). Also, do you see any evidence of overheating contacts in the 12-position connector that mates the cabin harness with the EFI harness under the glove box?
Has the symptom changed from the "random misfire" which is the title of this post?
--
Art Benstein near Baltimore
An Indian chief was feeling very sick, so he summoned the medicine man. After a brief examination, the medicine man took out a long, thin strip of elk rawhide and gave it to the chief, telling him to bite off, chew,and swallow one inch of the leather every day. After a month, the medicine man returned to see how the chief was feeling. The chief shrugged and said, "The thong is ended, but the malady lingers on."
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So I cleaned and wire brushed the harness connector underdash. Because the perverse gods of car repair punish those who say they fixed things, I won't say that. :-)
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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No. Wider. Two rows of contacts. Hinged.
Aaaaand it's back to it. R&R CPS for green connector and rotted insulation.
Ran some of the day and then back to the same old tricks.
Sigh.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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"No. Wider. Two rows of contacts. Hinged."
What exactly do these four sentences mean? Is it like you didn't see what was in my picture, but you saw something else you think pertained to getting the power to the engine management system?
--
Art Benstein near Baltimore
Deja Moo: The feeling that you've heard this bull before.
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I cannot find the connector of which you thoughtfully included an image.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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I'm trying to parse the sentence "Hinged" and all I can come up with is one of the control unit connectors which lock on one end to snap down.
Probably moot, as more reading gives me the impression you're back out of suspecting a poor electrical connection and into looking for a vacuum problem. OK thanks.
--
Art Benstein near Baltimore
I went to buy some camouflage trousers the other day but I couldn't find any.
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Precisely. But I see that runs leftward, not to the ECU.
For a brief time back in June, I heard a rattly sound from the brake booster. Went away. But I keep coming back to "What if after an hour plus of operation with ambient temps in the 90s the booster reacts poorly to the first few brake inputs after leaving the freeway?" That's a big hose to be leaking vac. I'm going to put a vacuum gauge on and watch it when shit gets real.
The good news is that when she runs, she runs better and better thanks to new plugs, cap, rotor, wires, CPS, coil, intake gasket, valve cover gasket, flame trap, breather box, AMM, vacuum lines, alternator...
:-)
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Ran for an hour and a half in coolish morning temps. No problem whatsoever.
Return trip, after getting off the freeway, in the same place as always, it started to die. Surging, getting weaker by the minute, not responding to throttle input well.
It will cool off and run great, I'm sure.
Wit's end!
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Ok, now you went and done it!
Not sure what it was but did you just put in a clue?
After you got off the freeway, at the SAME place as ALWAYS!
You need to enlighten us to exactly to what that is!
Is this some electro-interference dead zone? Are there some microwave antennas in the area?
I'm not as crazy as it sounds! Is Air Force One stored around you or somewhere near the conk zone?
Any ham radio operators around! Are you one of those high wattage kinda guys?
Sure hope you don't have a pacemaker in your future.
Yes, Really! I might be yanking your chain some what. (:-)
How about is this area being sloped or hilly? I'm thinking, If there were water in the gas tank that could get sucked up.
Your saying you can and are repeating this drop in performance. There has to be a logical connector.
What is unique about this portion of road. Please describe.
Is it a certain amount of miles down the road from your favorite gas station?
How many miles on the head of this engine?
Has it been recently rebuilt? I'm curious about the cooling period.
Could there be a sticking valve that you don't notice until it is at a slower speed?
What weight oil, brand, and Dino or synthetic are you using?
Are there any additives involved?
Have you ever tried a Rislone detergent additive?
What is the oil consumption rate per thousand miles.
Help us out with more notations or clues of how you drive, anything trivial could help.
Phil
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Original head. Never off, AFAIK.
Flat, hot Florida.
No gas station correlation.
Castrol 10W40
No additives
Never used Rislone.
Hard to say on consumption, as I need a main seal and have been putting it off despite the seepage. I'm going to suck it up and do all the seals on Tranny Drop Weekend.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Problem arises on the chunk of asphalt I hit 3-7 minutes after coming off the freeway. No RF emitters noted, no alien beams, no static fields.
No codes. Exactly the same each time. Feels just like a bad AMM, but it will do it with a new one.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Ok you said.
"Problem arises on the chunk of asphalt I hit 3-7 minutes after coming off the freeway."
You say it acts like a bad AMM which is like a default limp mode. So it's losing power to your throttle commands as if is it being told to idle while coasting but you just want to maintain a steady speed.
I'm pretty sure it's the throttle switch that initiates the ECU program switching. I have read the ECU needs proper RPM and speedometer signals on a '93 car.
Are we talking about a 2.4 or 3.1 series with the correct switch installed? Just wondering (If) they can be switched.
Is the engine coasting dead, as in quiet, without backfires or shuddering. Or does it go bucking and clacking trying to run?
Have you made any prior stops before it happens or is it upon the first time you go to stop and make it stop or upon you getting up to a slow cruising speed?
We are assuming it's the original booster as like on the head was not reworked.
Does this car have an EGR VALVE or any remnants of one being removed by any PO?
What is the speed limit or your average speed on this route?
That all I got so far!
Phil
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Yep. After cooling off, all is well.
Interesting, considering that it ran perfectly for a month and a half after cleaning the two-row harness connector above the passenger footwell.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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I like your thoughts of perverse automotive gods! I wonder if they are like a cult!
I know there are fanatics or enthusiastic car owners!
If so, get two plies of those red or blue hands towels and put them under your knees except point you head west! Your read end will then be nice and high towards the east!
That should provoke something with the higher ups!
I say this as to whatever is wrong with your car, will totally quit or blow it up! (:-)
I keep trying to think with those thermal issues and with the electronics at this point.
I know Art and I ran down on the CPS. But WE never heard that you changed it.
I don't blame you, as it works. But then it's right behind the head of the engine. It's is below it and gets heated up BY the water jacket temperature through the transmission housing.
That might be the delay and longer on cooler days?
I'm Totally making up a story here!!! The Gods like tall stories about themselves! I'm working on that for you!
It seems so far fetched and so sporadic as well! But we know these CPS's can act very strange during failure.
Art has scoped them out, I mean literally with an oscilloscope! He has seen "weird" wave patterns develop.
Maybe this shakes up the ICU which talks to the ECU and things fall out of program perimeters.
In and out of limp modes so fast.
First a missing scenario and then the "crosstalk" deteriorates into scramble eggs and nothing works.
Acts like AMM but from the ECU' s own programs? Limp is "default" when all else fails. The AMM is not limp mode, the ECU side is!
It messes with fuel and timing to try to maintain harmony. Those gods must have a choir. Music is about the only good thing about having a religion anymore.
It may boil down to one or the other, CPS or ECU and I'm the last to blame electronics but that CPS it's on my "crap" out list!
How many people carry a spare ECU?
How many people use to carry a set on ignition points or condensers in the real old days?
Hall sensors and the CPS is the Same thing.
Phil
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Harness connector shows no sign of hot contacts after one hour of operation. No discoloration typical of such (I've battled the melty 740 fuse block, so I know from hot plastic).
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No OBD codes whatsoever.
No CPS R&R yet.
No fuses at the battery. Fuse 6 terminals clean n shiny.
I will check the harness.
Yes. Symptom mutated along the way. This was an irritant which is now a problem.
I swear, it feels like a big vacuum leak. Harder brake pedal when misbehaving but still running. I haven't been able to track it down, though. It ONLY does it after long, hot drives. I mean,I can run for an hour and it's fine. Around the 90 minute mark I know I'm on borrowed time.
Runs smooth and even... until it doesn't. And once it starts misbehaving it gets progressively worse until it stops running. But cool off and things go right back to normal.
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I agree with DAN and you that this business of the Car stopping because of the AMM has pitched its last fork of hay in the air for me as well!
It appears that the cure, though temporary, has something to do with the left fender area and flopping stuff about!
I believe it might be the harness of both the AMM and the Power Stage or ignition coil relay.
This is not the first time this has passed under the eyeballs and scopes of many on the board!
It was a recent problem with another poster and it very well be the connector or wires. It was his!
Art Benstien has suspicioned it, as well as I and the proof just keeps getting better all the time.
If you have not had that item out from behind the battery, now is the time!
As I remember, when you are looking over the fender and down onto the PS, there is a ground wire all by itself running out, to the left and forward of the harness to a screw into the fender.
It may be hooked in with one or more wires. Make sure you redo that connection.
Inspect the PS connector, on both sides, for corrosion or loose pins. Trace a few pins up to the coil and look for the same voltages at both places to be within a tenth of a volt or a set of zeros, on the same side of that circuit!
As I understand it...?
The ground wire mentioned earlier, is the circuit part, that gets broken by the relay, to turn off the primary and Fire the coil.
If that circuit dies, ALL on its own, the coil dies as well! No component failure, just Mister Gremlin at Large!
Scrubbing the heat sink base clean, all around and applying some fresh conduction paste is good maintenance.
We are at the bottom of the hay stack, the needle has got to stick up somewhere real soon! (:o)
Phil
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Have you replaced the power stage / ignition amplifier? If this is related to a failure of the PS once it is heated up and then it works when it has cooled off at a minimum you might want to put a new coat of thermal paste on the back of it.
This is another part that is good to have a known good one available for trouble shooting.
Dan
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New power stage, yes. Thanks!
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Hope not. This one is less than a year old. To
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Only one way to find out, swap in a known good spare.
Dan
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Indeed. Would that I had one lying about. However, I did have a known *bad* spare. Its fault was not the same as this symptom, though.
R&R with the known bad AMM totally ended the random cutting out. Smooth, but kinda weak. I remembered about ten minutes into my test drive what the old one had done: failed at idle and low rpm driving. I felt it wanting to die just blocks from home, but got her into the driveway.
I wish the bad inputs from the AMM had been sufficient to set a CEL. Oh, well.
Thanks for the insight.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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You should have one for times like this as well as several other items for troubleshooting problems.
Dan
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Replaced the AMM.
Ran like a top. I mean just beautifully.
For about 200 miles.
Then, at highway speed, the classical AMM failure symptoms. Lag at throttle input, but marginally functional absent any change to throttle.
And, of course, once I was off the freeway things got real.
Disconnected the AMM and it started right up. It ran for a few minutes, anyway, and then got really really ugly. "Limp home" mode was more like "stumble home drunk with a weasel attached to your face" mode, so I have another problem under the surface, apparently.
The air box thermostat is screwed shut on cold input, so I know that did not fail the AMM. I'm guessing it was just a crappy reman from Advance, but I'm going to have to get another one under warranty for now.
Ideas on the complete failure to limp? O2 sensor?
I'm going out to swap the AMM with the "known bad but not THIS bad" one. Bet it fires right up.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Limp home mode is not a cake walk and far from normal. Generally rebuilt AMM are not good, you are better off with a new Bosch or a known good used one.
Dan
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But it ran soooooo well for those 200 miles.
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~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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Yeah, I'm going to spring for a new one soon and make this the known good spare while it's still good.
--
~graymatta '93 240, '92 940, (departed) '85 740 and a world of air-cooled VWs in my past
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A stumble, or what some may call "bogging," could also be caused by a failing throttle position switch (LH 2.4) or sensor (LH 3.1), the TPS.
A failing TPS is very intermittent as it begins to fail.
I'll guess you have an automatic transmission?
As part of your diagnosis, in addition to the usual fault-causing suspects, so numerous to define here, you could expedite throttle position switch or sensor by disconnecting and reconnecting the switch cable. As I did.
I guessed it was the TPS both times in mine with LH-Jet 2.4. No fault codes, either.
Worked for me twice. May not work for you.
cheers,
Dud.
--
First the alternator goes wonky. Now, yesterday, he finds his no more than five year owld OEM Volvo blue box water pump in his 1991 240 sedan is leaking through the bottom weep hole. Meaning it is a part failure. An OEM Volvo water pump for B230. Nice rivulet of young (no smell) coolant mix out that bottom weep hole yesterday. Prestone / Distilled water at 50/50 mix. In small, powerless garage with the apartment complex legions driving buy in newer cars less well cared for, and are thus, very noisy.
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