Howdy folks-
I've recently had success in bringing down a high idle but am now chasing down some gremlins to smooth out the idle and get rid of the bad exhaust smell.

Today I've replaced my old plugs which were old, and checked timing....timing was very advanced!
Based on all the little "fudges" I've seen so far my best guess is that someone messed with stuff to get this car through DEQ/emissions (it last lived in Portland).

My idle still isn't smooth and the exhaust is stinky. Isn't running rich.

I checked the dwell for the fuel mixture via the test plug in the engine comp and found the dwell to be 38....seems like my mixture is lean which makes sense.

The above dwell test was taken with the 02 sensor still attached, I'm unclear if its supposed to be disconnected for this test (the Green book procedure uses a CO meter to do the fuel mixture setting which I don't have).

So basically I'm wondering if I need to disconnect the 02 to get the specified 45 dwell or if it matters.

Also, on the topic of O2, how does one test one? I have the Green book info but once again the procedure involves a CO meter.

Hoping to get this sorted out, the car does drive better now with the timing back in the right neighborhood but I know the idle can be smoother and it shouldn't smell so nasty!

thanks,
Abra

Just wanted to post a conclusion to this.

I've been hunting down some gremlins in my cars idle, as has been posted about.
I couldn't find any obvious vacuum issues but I suspected my injector seals, the injectors were all loose and WD40 sprayed while the engine running had some effect.

I just did the seals yesterday, a very straightforward job (although I had new injector holders on hand so I didn't deal with trying to save the old ones, so getting them off was easy, I just destroyed them!).

Long story short the car idles SO much better now. The leaky seals were a big big part of the picture here. I plan on pulling the throttle body to clean and replace the gasket and service my flame trap at the next oil change, but honestly I'm VERY pleased with the results I've gotten.

Also I plan on dialing in my mixture but want to wait to take it in to a Volvo shop in Portland where they have a CO meter, then they can really dial it in to the right spot.
thanks ya'll!

Abra

Hi,

Glad to hear you have made progress.

Here is something that I need to ask about your 1981 as I have only the 1978 K-Jet.

On my car that has a Lambda system using the O2 sensor and a frequency valve that buzzes when things are working to adjust mixture.
The Dwell meter measures the cycle time it dumps or holds fuel.
This causes pluses in the constant flowing injectors, above and below the fuel distributors flow rate, in amounts that the O2 sensor dictates. The ECU acts to correct the burn for emissions with this. This is probably what you have gotten figured out.

In watching your thread your idle valve is electrically operated, more like the LH. Mine are strictly using electric heating elements during warmups to move its vanes.


What I want to talk about is a relay located on my car over by headlight dipper on the left fender.
When the engine is started it connects up the O2 sensor to the ECU.
This relay also carries another circuit within it. It connects up the frequency valve to the ECU so it will buzz and do it’s job.

So my question is does your car still have that frequency valve there to buzz? If it does, then it’s like mine. My feeling the early eighties are hybrids leading to the LH.

I wanted to let you if the relay fails the car will not start well. No buzz could mean a bad relay. The relay can fail before the frequency valve.

Either side of the relay can fail. Just like the system relays on the LH cars. So the ECU could end up only getting only half it’s infomation needed. If it’s not getting it there is a default base line it uses that is close to a well tuned engine but of course not self tuning.

So if the new O2 does not quite do the job in getting the right dwell reading or emissions keep this little one inch square silver relay in the back of your mind.

Phil

That's a good question about the Lambda etc, I was wondering about that myself in reading other posts about similar issues.
I've never had a car with Lamda so I'm not familiar, my Green book copy for K jet repairs makes no mention of the system and I'm thinking my car does not have it.
I think maybe you're right about things transitioning to LH in the early 80's, my car is missing the black idle adjust knob that was found on most K Jet systems, like you said the idle is automatically adjusted for via the air valve mounted on the top of the engine.
I also have a sticker on my engine compartment that says my car meets the California emissions standards, must have been a Cali car.
I have a new O2 sensor showing up Monday, it was so cheap I just bought one. I have repair records from the previous owner for the last 17 years and the last one was replaced many many years ago...from what I've read they only last so long so I'm gonna replace mine with a fresh one right from the get go, they're easy enough to replace.
After that I'll see where dwell is, if its still off I'll try to adjust with the long 3mm allen.
It does seem my reading of 39 isn't TOO low, if the baseline is 45....just a bit rich.
thanks
Abra

Volvo Problem Solver. it gives the directions for setting the CO with a Dwell Meter and also for setting it at the O2 using a Digital Volt Meter, all in a single page.

Great compilation of Tech tips written by and for working Volvo mechanics...covering older models. Out of Print sold by IPD and Volvo parts providers in the way back for $65 --- printed before lazer printers tho so digrams are primitive computer stuff----But the Info is the best.

Go to: http://volvowiringdiagrams.com/

scroll and look inside the Trouble Shooting Guides Folder
Download: Volvo Problem Solver Advanced Edition-1.pdf

If you replace the O2 you will have to reset the CO using that adjuster.
If your Dwell Meter really only has an 8cyl setting then use a DigVolt meter to take the reading off the lead to the O2 Sens....see the same page in the ProbSolver.


Also--- you say your dwell meter only reads 8 cyl....???

what kind of meter is that...all Dwell Meters I've ever seen should have a switch that the meter to read 4cyl, 6cyl, or 8cyl.
Dwell meters are old school tech devices designed to set the point gap on engines with points-condensor ignitions. Most are dual meters so called Tach/Dwell meters that can be switched to read either Dwell or RPMs.

Your CAT may be causing the smell. But until you sort out the rich/Lean and other maintanence tweeking and take it for a run on the highway you won't know.

My dwell meter is an old analog dwell/tach/volt meter. It reads 8cy and 6cyl, i've always used it on 4 cyl only and did the math, for example doubling the RPMs etc.
I should note that the smell got better after I put the timing back in the appropriate ballpark, its still a little smelly.
Also, before all this happened, when the car ran fine, before the idle hiked and I started down this goose chase, there was never a smell!
I haven't had it out on the highway since I've been tweaking recently, but will do so this week. Its always been a champ on the highway.
Hoping to get things to a good place this week, thanks for the links to info.
Abra

Read this.

MVP Tech Tips

Setting base idle specs. on cars with K-Jetronic fuel injection and CIS

Many driveability and running problems can be traced to improper base engine settings. Setting your base idle specifications is always the first step when trouble shooting any runability problem. By following the steps below the source of most problems can be identified

1) Check for air leaks by spraying carburetor cleaner on all intake hoses and gaskets including the injector seals. Any fluctuation in idle while an area is being sprayed means a leak. Repair any leaks you find. Don't spray carburetor cleaner on hot manifolds as it may cause a fire.

2) Remove and clean the throttle body, then reinstall it using new gaskets. Make sure the throttle switch clicks as soon as you crack the throttle (adjust as needed).

3) Start your engine and let it warm up fully.

4) Set ignition timing to the manufacturer's specs.

5) Now use a voltmeter to verify that your 02 sensor is working properly. Connect the red probe from the voltmeter to the 02 sensor wire where it is connected to the large green wire. Connect the black probe from the voltmeter to ground. A good 02 sensor will fluctuate between .2 and .7 volts if your mixture is anywhere close. Replace the 02 sensor if needed.

6) Go to the left inner fender well and find the blue and white pigtail that sits besides the ignition ECU. This is your CIS test point. Ground this connector and adjust the throttle plate to 750 RPMs. Readjust the throttle micro switch as needed. Remove the ground from your test point, the idle should be close to 850 RPMs or 950 RPMs on turbos.

7) Next to the blue and white wire is a red pigtail. This is your CO test point. Using a DVOM that measures duty cycle connect the red probe to the red pigtail and connect the black probe to ground. The proper duty cycle is around 50%. Adjust the base CO through the small hole in the air flow meter using a long 3mm Allen wrench. Adjust it to 50% duty cycle. A dwell meter may also be used to set the CO. With a dwell meter adjust the CO to 45 degrees.

Congratulations! You have just set your engine's base idle specs.

Note: With CI fuel injection the lower the duty cycle or dwell, the richer the idle fuel mixture. Factory specification for base CO is a duty cycle of 54%-65% translated to a dwell reading of 49-59 degrees. In our experience we've found that a slightly richer idle CO provides the best idle and the best starting.

Don't disconnect the O2 sensor for any of this.

If your dwell meter doesn't have a 4 cylinder scale use the 8 cylinder scale and multiply the reading by 2. 22.5 degrees on the 8 cylinder = 45 degrees for your 4 cylinder engine.

If you don't know how to use the volt meter post back.


--
'80 DL 2 door, '89 DL Wagon, '15 XC70 T6

Still can't find the blue/white wire mentioned in #6 for procedure.
Looking at my diagram in the Green book it shows wire 12, from control unit in passenger comp, ending at the coil. They say to remove wire for 1st idle setting, then adding it.
Maybe I don't have the blue/white test point in the engine comp.
But I still can' figure out how to remove the wire from the black plastic connector thingy, the book says nothing about it, and when I do google searches I must be using the wrong terminology.
Anyone tell me how to get a wire out of the plastic multi connector that plugs in the the control unit?

Abra

In the Bentley manual for the 240 Turbo it shows setting the dwell check midpoint 41-44 and adjusting midpoint 43 degree's. This is the way I have always set the dwell so what is the correct way to set dwell?

So I'm realizing there's something in the sequence for timing I've been skipping.

Its the part about grounding the blue/white wire, I can't seem to find that wire, I do see the obvious red wire for checking the mixture dwell, but can't locate the blue/white wire.

In the Green book they have you removing the plug from the box located at the passenger foot well, pulling wire 12, then reconnecting, which must do the same thing.
The problem is I can't figure out how to pull the wire out of the plastic box its in!

Something's up, my idle sits around 800 then I bump up the throttle stop screw a little at a time and it jumps to about 1000 RPM....can't get any of the in between.

Also check O2 and it seems ok, can't adjust mixture yet as my 3mm is too small/clumsy to access....once I get a longer 3mm I want to dial that in a bit.

thanks,
Abra

Where is this blue/white wire referenced?


--
'80 DL 2 door, '89 DL Wagon, '15 XC70 T6

6) Go to the left inner fender well and find the blue and white pigtail that sits besides the ignition ECU. This is your CIS test point. Ground this connector and adjust the throttle plate to 750 RPMs. Readjust the throttle micro switch as needed. Remove the ground from your test point, the idle should be close to 850 RPMs or 950 RPMs on turbos

I did double check the wiring diagram and I should have this wire but I don't seem to.
Procedure in the Green book points out removing the wire #12 but I can't get it out of the connector.
Not sure I totally understand the reason for grounding the wire/removing the wire, then re connecting but I guess if that's the way they say to do it then there must be a reason!
Abra

Hi,

I will try to shine a light on your 1981 version of K-jet, that I told you I knew less about because your car is newer than my 1978.
I didn't pick a LH until 1986 and later on I got myself into a 1984 LH 2.0 . So, I know how it stepped back a tiny bit in components.

The information you are getting twisted up because your car is a hybrid mix of updating the early systems achievements. In other words, Your 1981 system led more to the LH thinking but was not quite there yet.
The early K-jets, like mine met emissions standards or actually exceeded them without an EGR or Air Pumps. It worked with a totally mechanical system except for the ECU that was built to worked the components using pressure, the frequency valve and the New O2 sensor!

It turned out that O2 sensor was better than than they thought it would be. It was more accurate and faster. It showed them how "slow" the frequency valve was at swinging the mixtures per cylinder.
The dwell meter swings the same way ... Slow as the O2 sensor but far faster.
This why there is not a fixed dwell setting but a ball park illustration shown in the manuals.

They still have to use the Co2 meter, as the final out come, to pass emissions laws globally. This push the bar higher to slowly dropping the idea of using a totally control pressure system.
It is amazing how good the system works without so much wizardry!

The electronics got faster as the injectors could be made to use electricity. The LH learned to incorporate the how to control air from the K-Jet air controls using rotating vanes but I have yet to understand why they used a wax thermostat, to control heated air, to one of its most important components, the AMM. Old schooling ruled, to be cheap, I guess!

When looking at the readings of the O2 sensor(s) this is the reading is a must despite the Co2.
If you look at the advancements, if one can call it that, on all make cars, there can be as many as Six to Eight sensors scattered from bumper to bumper.
Reading both banks and all their fancy exhaust pipes. Before and after the converters. On the big Fords and twelve cylinder exotic cars it's that bad! Moving valve timing and cutting out cylinder firing made the internal combustion engine an expensive maintenance nightmare!



What I'm suggesting doing use a voltmeter to set your mixture as that is what the ECU's are doing!
Hook it up to read the voltage while its operating right on its connector to a good grounding point.

Get it hot by revving and see if it stays in the middle swing range with steady throttle.
Expect it to go real high and low when rapidly changing throttle positions but lay back into that mid range of 0.5 at idle or going down the road. It will never really hold it "dead nuts" on, because it's so accurate and fast!

The ECU's in all cars are set up to "try to run an ideal mixture" but will always have or should have "the tendency" to let the engine hit a "richer rather than too lean a mixture" for the reason of engine safety. This is so as not to create hot spots on Pistons or burn valves with whatever fuel used or conditions that change.

To answers the question about setting the idle without the blue wire on the LH's and then disconnecting it goes back to setting the auxiliary air valve on the K-Jet. This was your fast idle/cold starting mode.
On the K-Jet you had to have the engine warmed up. You set base idle with the throttle complete close off or shut with the stop screw and using the black knob to bypass enough air to idle properly low so the car did not creep forward with an automatic transmission.
This was around 850 or less maybe give a little or not depends on your engine tightness and other factors at the time.

For cold weather you adjust the auxiliary air valves vane open sideways by adjusting a spring tension against an arm of heated finger to let more air in.
The heater was made cool enough that it warmed up approximately as the same speed as the engine.
Same goes for the fuel pressure controller. This is factory set, so the air valve is mechanic friendlier and accessible. Once set it should idle without help from the gas pedal. I say should?

The LH grounding procedure of the IAC is the same. Only it has a range of opening or being closed has to be set right at the place below the lowest idle point, so it, can take it up from there if the engine if cold by the ECU only.
There is no using a foot on the gas pedal allowed on the LH.
This is why it revs up after being released from the ground wire.

A good IAC should rev up past idle speed everytime upon starting. Then it must drop down to the hot idle speed of 750. It must maintain its self there no matter what because the ECU says so or you might get a fault code.
This was an emissions requirement to use less fuel so it will trigger a light on later cars.

You see, procedures are very similar, so I suggest, if you have question on the K-Jet, look forward to the LH and see how its done with the better information. Then is all about looking back by reverse engineering how they did not use electronics. The car is really simpler and once dialed in stays that way with clean fresh fuel!

There is a learning curve but think of it as another part of the ride on the roller coaster of life!

Phil

Phil,
Thanks for that reply, super informative. Things make a little more sense now.
I just drove down to Portland and back this weekend, 225 miles round trip, and the car totally ruled on the highway (it always has). The idle was the same as its been...low, lumpy...smelly exhaust.
My plan is to replace all the injector seals, clean throttle body with new gasket with the throttle body and air bellows out I can really check for air leaks...then start over with the idle procedures.
I still can't figure out how to remove a wire from the plastic multi connector that goes to the ECU in passenger comp....

thanks,
Abra

Hi,

Glad to hear your car is running good enough to take a nice trip.

The answer on how to remove a terminal from a connector socket is to depress a tang down that’s on the terminal inside the housing.
The holes in the connector that the terminals fit into have a certain orientation established by a slot on one side of each pocket. Study the front entry side of the connector.
All the terminals will be align in one direction and are usually numbered on the connector or where it is going to fit.

The metal terminal will have a cutout tab or tang placed on the flat or solid side a the terminal. All of his will up inside and out of sight.
This should be raised or sprung upwards to protrude outwards. It will be higher by about 15 degrees than the rest of the terminal. If not you can lift it with a small knife edge.

When inserted into the connectors pocket backside the tab slides down the groove until it passes a shelf or higher relief area. The slot runs all the way through the pocket to the front.
This is when the tab or tang springs upward to engage in behind the shelf.
This locks the terminal from moving back outwards as the front of the terminal will hit the bottom of the pocket. This is a forward stop.

What you want to do is find yourself or make yourself a narrow and thin probe to slip down the size of that slot from the front. You need make it to slip in the thickness of the gap up and down with a blunt end.
You make it long enough to reach as far as the terminal is long. The tab will be halfway of that.
The tool is usually made out of a paper clip, by grinding or filing, or you can purchase a cheap set small jewelers screwdrivers and reshape them.
As you work the tool in, pull a slight tension on the wire. When you hit the tab or tang down enough it will release the wire.

It’s then you can inspect the terminal for corrosion and shape to be like all the others.
If it is still good you spring the tab or tang back up to it will again tension the terminal in the pocket. Give it a little extra tug to make sure it is locking in. There should be a tiny bit of looseness in the pocket so the pin can align up to the terminal or vice versus.

If you think it a little bit of work you are right. That is why most of the time we don’t remove them and we try to measure voltages or resistances by using the voltmeter probe lead to “Back Probe” the circuit. You just got to make sure you are touch the metal crimps on the wire down in the pocket.

I don’t know what you are looking for but while you have the connector off use some light spray very lightly on the female sides. Push the connector on and off a couple times as this will help clean the terminals with the scrubbing action of them slipping back and forth. I personally like LPS One for this but there are many brands of anti corrosion concoctions out there.
Just keep it to a light film.
Making it Drip can cause problems and is a waste if it’s going everywhere.
Depending on you weather environment doing this about every five to ten years, to the ECU, will keep it tuned up.

It’s probably never been done so it cannot hurt!
Phil

Ok that makes a lot of sense, I will try to get the wire out.

The only reason I want to do this is its part of the idle adjustment procedure.
The manual states to "remove wire 12" from the connector, adjust idle to 800 with throttle stop screw, then re-connect wire.
I think I'm supposed to have a blue/white wire in the engine that I can ground to do the same thing....I can't locate it, it should be next to the red wire used to set/check dwell for mixture.
Up until now I've just been skipping the above step "removing the wire" and just adjusting the throttle screw. But I figured it would make sense to do it "by the book" since things are a little off.
New injector holders are showing up this week, I have the seal kit, gonna spend some time getting this car dialed in.
thanks,
Abra

Hi,

Glad to hear your car is running good enough to take a nice trip.

The answer on how to remove a terminal from a connector socket is to depress a tang down that’s on the terminal inside the housing.
The holes in the connector that the terminals fit into have a certain orientation established by a slot on one side of each pocket. Study the front entry side of the connector.
All the terminals will be align in one direction and are usually numbered on the connector or where it is going to fit.

The metal terminal will have a cutout tab or tang placed on the flat or solid side a the terminal. All of his will up inside and out of sight.
This should be raised or sprung upwards to protrude outwards. It will be higher by about 15 degrees than the rest of the terminal. If not you can lift it with a small knife edge.

When inserted into the connectors pocket backside the tab slides down the groove until it passes a shelf or higher relief area. The slot runs all the way through the pocket to the front.
This is when the tab or tang springs upward to engage in behind the shelf.
This locks the terminal from moving back outwards as the front of the terminal will hit the bottom of the pocket. This is a forward stop.

What you want to do is find yourself or make yourself a narrow and thin probe to slip down the size of that slot from the front. You need make it to slip in the thickness of the gap up and down with a blunt end.
You make it long enough to reach as far as the terminal is long. The tab will be halfway of that.
The tool is usually made out of a paper clip, by grinding or filing, or you can purchase a cheap set small jewelers screwdrivers and reshape them.
As you work the tool in, pull a slight tension on the wire. When you hit the tab or tang down enough it will release the wire.

It’s then you can inspect the terminal for corrosion and shape to be like all the others.
If it is still good you spring the tab or tang back up to it will again tension the terminal in the pocket. Give it a little extra tug to make sure it is locking in. There should be a tiny bit of looseness in the pocket so the pin can align up to the terminal or vice versus.

If you think it a little bit of work you are right. That is why most of the time we don’t remove them and we try to measure voltages or resistances by using the voltmeter probe lead to “Back Probe” the circuit. You just got to make sure you are touch the metal crimps on the wire down in the pocket.

I don’t know what you are looking for but while you have the connector off use some light spray very lightly on the female sides. Push the connector on and off a couple times as this will help clean the terminals with the scrubbing action of them slipping back and forth. I personally like LPS One for this but there are many brands of anti corrosion concoctions out there.
Just keep it to a light film.
Making it Drip can cause problems and is a waste if it’s going everywhere.
Depending on you weather environment doing this about every five to ten years, to the ECU, will keep it tuned up. It’s probably never been done so it cannot hurt!

This is embarrassing. That was from my own information. All I can say is I haven't done this for a long time and my 1980 car has the aux air valve instead of constant idle. But really...

Perhaps the blue/white wire is not there. I see it on page 42 of the greenbook for CIS but not on page 30 of the greenbook for '81 wiring diagrams.


--
'80 DL 2 door, '89 DL Wagon, '15 XC70 T6

Sorry but many hate me because here because I don't Suffer Fools....that my dim bulb friend, was once considered an attribute.

I sent you a link to HOW TO DO IT cauze we are Volvo Mechanics who get paid by the hour...... The Volvo Problem Solver.
If you can't get the info from that ...why bother posting Questions here. We Don't know any more than those Working Mechanics who look at this stuff day after day...and Sold their knowledge for $65 per copy....in 1990 Dollars....around $250 these days. Including a Subscription to Updates.



R U The Brickboard's first Troll????

Have you ever really owned a Volvo? U keep saying...not like the LH Volvos I know about?

Hmm...not sure how to respond to this. I am grateful to links you've posted and I've gotten alot of help from reading through the material. I don't have much time to work on the car right now so sometimes I post simple questions since alot of folks have had similar issues etc.
As mentioned this is my 1st K jet although I've owned (and worked on, as a DIY "shade tree fix it man") several late 80's 245's. I typically do all my repairs but haven't ever had a K jet in front of me until now.
thanks,
Abra

If you can't find it elsewhere--Snap-on makes a 1/4 inch drive long 3mm. I find that sometimes you need to give a squirt of carb cleaner directly down to the allen screw and blow out with compressed air. Lots of shmootz can build up in the 3mm void -- make sure the allen tool is securely inserted. -- Dave

Just realizing the one thing I haven't done/am about to do on this list of procedures is the throttle body cleaning.
I haven't heard much feedback from K jet folks on how to approach this, on LH engines its pretty darn easy, on the K Jet it looks hellish...any thoughts on how much of a PITA this is gonna be? I'm kinda putting it off for last....

Abra

I have done this on both systems (the 240's in my signature line) but not recently.

I do recall they are very similar. The K-Jet was no more difficult than the LH.

Except the rubber boot on the K-Jet can be a pain to get back on correctly. There is a trick but I don't remember what it is at the moment.*

The only other thing that comes to mind is one of the three nuts for the throttle body is a bit tedious. The one to the inside, I believe. I think I used a box end and could only turn it about 1/8 turn at a time.

Take notes. Take a picture. Draw a diagram. Whatever. There's not that much stuff to disconnect/reconnect.

Use a new gasket, obviously.

When I did the K-Jet car the cleaning consisted of no more than wiping it with a rag and some carb cleaner. It was just a slight film of carbon that probably was not affecting anything for the worse.

The LH car had a lot more miles on it and there was definitely a gunky, crusty build up. I forget what solvent I used but it cleaned up fairly easily.


* Edit

A post from 2003 by one of the better minds from the old days, Don Foster.


https://www.brickboard.com/RWD/volvo/682558/220/240/260/280/always_struggled_installation_whats_trick_nmi.html

Notice who asked about it.

It may not be as easy as it sounds but I believe it works. Be careful not to tear the boot at the seam.


--
'80 DL 2 door, '89 DL Wagon, '15 XC70 T6

Don Foster (near Cape Cod, MA)

a classic Volvo-ian

Thanks for that info!
Abra

Good info, thanks.
I do have my idle pretty dialed in as far as those steps are concerned, its just not very smooth.
I'm gonna test O2 sensor (which I suspect). Luckily they're on sale for $17 at IPD right now!
I have a meter for reading dwell, mine is for 8cy and my reading with the car warmed up was 19, which was how I got the 38 reading I mentioned.
So it seems its a bit rich, although I can't say there's any black smoke, the old plugs were not black at all. It is a stinker though, smells bad.

Hopefully this weekend I'll have some more to report.
thanks,
Abra