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I've got a stalling issue on my wife's 1993 Volvo 240 Classic wagon with the super rare manual transmission (not that it matters in this case), and I could use some assistance from the group. After swapping all the typical items like the white fuel pump relay, fuses, AMM, computers, pressure regulator, cleaning grounds, etc, I was able to isolate the problem to the fuel delivery system as I'm able to keep the car running on starting fluid being blown in via a vacuum hose to the manifold.
Having recently blown a main pump on my 740, I replaced the main pump and filter on this car, but without improvement. If anything, it got worse. The car could run for 5 to 7 seconds previously, and now it only runs for 2 to 3 seconds. I repeated the replacement again just in case the first two were bad, but still no success (so she's on her 3rd good/used pump now). I also re-installed the original pump on my 740 and it's running fine with it. Moving on to the in-tank pump, I found the factory original AC branded one to be intermittent and replaced it with a bench-tested good identical replacement but the stalling issue remains.
I'm grabbing at straws here. I can validate the pulse data signal coming from the flywheel position sensor with my oscilloscope, and likewise have checked the fuel injector pulse width modulation to see that it has good strong square waves while it's running and stalling out (thus not caused by the computer leaning out or shutting down the engine). Ignition problems are ruled out because I can keep the car going with starting fluid.
What am I missing here? During all the pump changes I believed I may have kinked a fuel hose from the filter outlet that runs forward to the fuel rail. -could it have kinked enough to cause this behavior? (while previously suffering from a clogged filter that's now out of the picture) I doubt it, but it's a possibility... What else could fail or get clogged to allow a brief startup but quickly followed by a stall out?
Any thoughts, suggestions, or advice would be greatly appreciated. Another friend's 240 recently was suffering from random stalling issues, that would resolve themselves in about 5 minutes, and a mechanic (not me) finally discovered some candy bar wrappers and pine needles floating around in his fuel tank that would randomly clog the in-tank pump takeup foot/screen. I have checked inside my tank and this is not the case...
I may end up building a temporary & separate fuel supply system with a pump and new filter running from a 5 gallon gas tank, just to verify the integrity of the rest of the system and narrow down my list of culprits.
Thanks in advance for any advice, and also a huge thanks to Art for maintaining his website and doing the research for us to benefit from on this topic. http://cleanflametrap.com/transferPump.htm
God bless and have a great day,
Fitz Fitzgerald.
'93 245 B230F with M47
'90 745 B234F
'88 780 B280F
(and formerly a matched pair of his & hers blue and silver '87 245 wagons that were driven till they rusted out at 385,000 miles and 435,000 miles)
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Hey everybody, sorry for the month delay in getting a reply to this thread. I've been pecking away at this issue as I have time, which hasn't been much. I have a wife who's due with our 2nd child in 2 to 4 weeks so things have been busy and most of my spare parts are in a storage unit (we're trying to buy a house and had to be out of our existing place right away).
Thank you all for the replies and the advice, I greatly appreciate it. I've attempted to check fuel pressure with a borrowed test system from a friend/mechanic but there's no T-junction in the kit. It's designed for only dead-head pressure testing on the pump, or pushing injector cleaner through the system with an air compressor, but can't monitor pressure of a running system. This kit will be "fixed" soon as I have a local hydraulic shop building up the necessary T-fitting adapter with connectors for me to do what it should have done out of the box. Parts are on order, but it may be a week before I have it due to warehouse inventory time.
Yesterday I attempted to power the car on a separate fuel delivery system, using an external pump & filter with the power wires tied directly to the battery. I basically took an entire system from hose at top of fuel tank, with pump and filter, to hose connection at fuel rail out of a salvage car in one piece (no kinked lines this time) and set it up on this car under the hood and supplied it out of a 5 gallon gas can with the Fuel Pressure Regulator return line dumping back into the gas can. Unfortunately, no success and the symptoms are the same. The car will start and run for 2 seconds and then hard-die immediately (gas pedal position does nothing to affect it so something is killing it).
I'm back to grabbing at straws here so I'm going to swap the fuel rail and injectors next, followed by more prayers and possibly beating my head against the steering wheel... I may need to look at how the computer controls the injectors further. I've tested the computer in another car already, along with the AMM and pressure regulator, and validated the signal data from Crank Sensor with a handheld oscilloscope plus validated the signal from computer to injectors. -but something is still not working... I'm starting to wonder if there's a stuck or broken intake valve or a blown head gasket breech between a cylinder on it's power stroke and one that's on its intake stroke. Another trip to the storage unit for a compression tester may be in order. FYI, the Timing Belt has less than 15,000 miles on it, and all seals including the front and rear crank seals are new as well.
Any other advice would be greatly appreciated. -and thanks again Art for the great website walk-through on the fuel hose and pumps. It was good to double check my work.
I'm praying for a break in the snow today to get some more testing done (working outside in a friend's driveway). God bless and have a great day everybody,
Fitz Fitzgerald.
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before you decide it must a fuel issue which it likely is do this:
have someone start the car while you wiggle the cps wire.
i have had a cps sensor look perfect to the eye and the car would run and then the car would shutdown with no warning.
it might or might restart quickly.
it turned out to be a cps that was failing in the hub that bolts to the bell housing bracket.
try this since it costs you nothing and takes a minute
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Thanks for the advice, and I went a step beyond that. I dismantled the back side of the Ignition and ECU wiring harness connectors so that I could hook up an oscilloscope to the wires while the engine was running/cranking. I used the scope to watch the pulse data from the CPS and verified that it was good data. After getting nowhere on the car for awhile, I went ahead and replaced the CPS (crank position sensor) with a brand new unit, and then used the scope to check the pulses again. It checks out good. I've even swapped in good/spare ECU and Ignition computers just to rule them out. Thanks for the suggestion and God bless,
Fitz.
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Boy, you are checking here and there while walking that white mile of snow too boot! Feel for you man!
I just had a wild thought to ask about. If, this is a 3.1 LH and If, you have checked out the throttle sensor connections for the variable resistance switch operation? You might probe it back to the ECU, since you had it open.
Like I said, it’s a wild thought. Because, I do not know what happens to the ECU program if it loses contact with the throttle circuits feed back?
Phil
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This sure sounds like a failed AMM, did you look at the pins in the connector to see if any have been pushed back and not in contact with the AMM connections?
Dan
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The pins looked good this summer when I checked them last, but I'll do that again today. Thanks for the advice Dan. I'm still indoors, hoping that the 20 degree air outside will suddenly warm up for me, but I suspect not. I should start bundling up to head outside soon now that breakfast is done.
Of note, about 7 or 8 years ago I had a friend's 1988 740 wagon have a wire go bad between the AMM and the ECU. That issue took a LONG time to find, several months if I recall. He could drive it, but not reliably as the connection was intermittent. I really hope that's not the case here as checking all the AMM pins against their destination/terminations is not a fun operation to do in the snow or any time of year for that matter.
God bless and have a great winter wonderland day. (go sledding or something!)
Fitz Fitzgerald.
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Do you have any OBD codes?
Dan
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Do I have any OBD-II codes? Checking previously while troubleshooting this issue, no, there were no codes stored. -and I almost wrote this off without bothering to check it. However, thinking I'll try anything at this point, I just went outside and pulled the codes again (I swapped car batteries earlier this week so for sure all previous data was erased). I was expecting to see all #1s from both ignition and fuel system as have happened previously, however, I just got a 1-2-1 code from the fuel injection! Holy cow, that's the bad-data error code for the Air Mass Meter. Directly from the service manual: "Fault in signal to/from air mass meter."
It looks like I've got an afternoon ahead of me tracing wires in the snow. I may need to dig through and clean the ground connections again too (also done previously).
Thanks again for the advice, input and suggestions. I greatly appreciate it!
God bless,
Fitz Fitzgerald.
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If the car Has Jetronic 2.4 injection, the trouble code for the Air Mass Meter will be stored if you unplug the meter....even if you're just checking the connection.
Before I went any further with the Mass Meter, I would erase the codes and see if the Meter sets the code again.
When you say that the engine will start and then die in about 3-4 seconds....
Try jumpering a 12V hot wire from the battery positive to the ignition coil.
Connect it to the terminal with the blue wire.
This will bypass the ignition switch and power the ignition system directly from the battery.
If it cranks and runs, the igniton switch may be bad.
Hope this helps
steve
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GA Fitz,
Dan's suggestion is great. Contact cleaner.
Best of all he knows a problem getting that AMM signal to the ECU is never anywhere else. It is right there, in the plug on the AMM.
What I've seen is the boot wears a hole in it. Hole in the boot. Well, it is 20 years old. Moisture gets in through the hole. Look for green where it should be silver and gold. Use a large paper clip as a pin release tool.
But don't overlook the possibility one of the tangs is not out far enough allowing the pin to back out of the housing when you plug it together. This has caught me before. I know fiddling with tiny things like that is a frightening proposition in 20 degree weather, so if you can just check to see the wires don't pull back in the connector, and then maybe just hit the thing with spray cleaner before you re-seat it, you'll clear that 121. If not, you really need to sub in another AMM.
Just wanted to catch you before you went down the wrong path with continuity checks for a very unlikely problem with that wire anywhere between the AMM and the ECU.
--
Art Benstein near Baltimore
Give a man a fish and he will eat for a day. Teach him how to fish, and he will sit in a boat and drink beer all day.
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I am a very blessed man, and also a very humbled man. It would seem that during a 2nd round of swapping Air Mass Meters in the car earlier, I forgot to clamp the accordion hose back onto the AMM after re-installing the original. Since then, I must have found and fixed the fuel injection system problem and not realized it because the AMM was preventing the car from running. So, while I can't pin-point what the original problem was (it's fixed now and has been for a bit), the 2nd problem was created by myself.
I hadn't yet disconnected the AMM wiring since swapping batteries last week, so I knew the 1-2-1 code for the AMM was a start in the right direction. Peering into the car, I found that the accordion hose was up against the backside of the AMM, but not clamped on. While they appeared to be connected at the top, they were not, and had a gap opening at the bottom of the connection from the housing and hose being tilted away from each other slightly. After clamping it together, she fired up and ran (on the auxiliary fuel system), then I transferred her back to the cars own internal fuel system and she started right up as well. I also took the time to clean the AMM wiring connections with a dental pick. I could not get the terminals to release from the connector housing in the cold and didn't want to force them and possibly break the connector (I have another, but it's buried in the storage unit). I need to re-pack the connector with dielectric grease, which seems to have insulated it well from corrosion as everything looked ok as I was cleaning it.
Here's a quick list of possible culprits that may have fixed the original stalling issue that I've done since the 2nd round of AMM & ECU swaps where my mistake occurred.
- Replaced in tank fuel lift pump (should flow through even if bad and car has a full tank of gas).
- 2nd round of Fuel Pressure Regulator swaps.
- Cleaning every ground connection terminal in the car relating to the fuel injection system and ignition systems per the 1993 240 Green book wiring diagram shop manual. I did a few of them earlier, but did EVERY one this time.
- I may have swapped the fuel pump an additional time as well. Could have been 3 or 4 swaps total during this ordeal. (first spare pump was seized, second and third pumps ran but stalling problem not fixed, fourth had a small leak in the housing that sprayed gas, final pump is on the car and may be the same pump from 2nd or 3rd swap)
The original symptoms were a loss of power while driving, and the car could barely keep itself running at idle. The problem was intermittent at first, increasing in occurrence, and then required a tow home finally. I'm hoping she's fixed but the proof will be when we have it on the road for a long drive.
It might be a day or two before the car is back on the road, there are a lot of things to be reinstalled that were taken apart during the diagnostic and troubleshooting stages. (like trunk interior, the exhaust system, lots of panels around the front passenger area, etc).
Thanks again for the help everyone and a special thanks to Art & Dan as well. I really appreciate this community and the assistance. God bless,
Fitz Fitzgerald.
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I tried to flag some of the posts as "answers" to this thread, but got back the following message: "Error: you do not appear to own this thread" I have yet to successfully flag any of my threads as answered.
Thanks again everybody, God bless, Fitz.
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Try some contact cleaner on the connector to the AMM.
Dan
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Hey Fitz, can't quite express my delight in hearing you didn't give up on the RWD Volvos for something more Detroity.
Anyway, here's what I would do -- and knowing you, you probably did it already and just didn't tell us. Given you've already assured yourself of good connections to the main pump (by changing it several times) you could trust a reading on the pump's terminals to an easier-done check under the rear seat where the connector is above the pump. Yes, I suspect a lousy connection, not a failed part. The connection is usually at the fuse, its terminals, the crimp on the faston, but depending on whether your 93 includes those PAL fuses at the battery, the list gets even longer. There's a 12-pin Molex between cabin and fuel harnesses above the passenger's knees too. Anyway, I suspect if you have good voltage at the pump, you'll have good fuel pressure. And I don't blame you for not having the adapter you need to measure it at the rail -- you need some kind of sharp 90 degree adapter to get a leak-free (read safe) connection to that Schrader.
Edit: The more I hear your word "kink" echo in my mind, the more it seems to fit the 2-3 second run scenario than a poor electrical supply to the pump.
http://cleanflametrap.com/fline.html
--
Art Benstein near Baltimore
My wife and I were happy for twenty years. Then we met.-Henny Youngman
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As Trichard suggests, check the fuel pressure.
Have you pulled an injector to see if it is being activated and delivering fuel?
You could probably apply voltage to the injector to see if it lets loose fuel.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.
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install a fuel pressure gauge to the schrader valve on the your 93 fuel rail.
turn key onto KII and measure pressure.
start car and watch the gauge as the starter turns the flywheel
once it start for X seconds note pressure.
is there a fall off just before it dies?
ps: i know of a 93 classic sedan with a 5 speed. yours is the only other 5 speed classic i have heard of.
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Fitz
Good to hear from you again
This sounds like a similar problem I had that turned out to be the main pump, can you tap on the side of the pump a little with a piece of wood? This may jar it loose enough to get it going and convince you it is an old tired pump.
When I did it on my daughters car it ran fine, got the car home and replaced the pump.
Dan
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My first thought will be to ask, are you moving the "same" main fuel pump check valve from one pump to the other ones?
Next question is are you jumping the fuse panel connections to verify the pumps are running before starting the car?
If you know the pumps run but you do not get the injectors to fire then you need to check their ground points or the ground connection of the relay connector and the ECU's grounding.
I leave it there as others will add some more ideas I am sure!
Phil
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