'92 245 won't start
 

'92 245 auto, 190k miles more or less, LH2.4

Not your typical "won't start" & I've searched the forum without success. In a nutshell the problem is that I have a 1-2-1 code (bad AMM), but it won't start with the AMM disconnected (won't do a "limp home"). It will give an occasional "cough", but never actually catches. I also noticed a tank fuel pump (?) sound which I don't think was there before: a one second or so "brrr" when the key is turned on. I'm reluctant to think that this sound has anything to do with the problem, but I'll mention it anyhow.

The history: for a month or so previously, on a morning when there had been an overnight rain or serious dew (it's not garaged), it would start OK but pulling away from a stop it would stumble (no power, unresponsive to gas pedal). It would run OK once it caught its breath, so to speak, & wouldn't stumble again after it had run a few minutes (dried out?). Then one rainy day it ran badly from the get-go and stalled at a stop, Restarted, but stalled again. Had to have it towed home.

The only thing that I've done is pull the code and disconnect the AMM .

Thanks,
Bob

maybe unrelated but did you pull cap to check condition cap/rotor?

+1 on silvermine. I had similar problems on my '90. I had stumbling and stalling on wet mornings but it would run ok after starting. On dry days it would start fine. On one dry morning, I verified it would start, immediately shut it down and then sprayed the distributor cap with a water bottle. It wouldn't start. Cap and rotor replacement solved the problem.

Also, check the timing. Move the crank so that cylinder 1 is at TDC and verify the rotor is pointing to the cylinder 1 spark plug wire.

Thanks for the replies. They got me thinking: I was totally focused on the 1-2-1 code & convinced that the problem had to do with the AMM. So I re-checked it by doing a hard clear (battery disconnect) & there is no longer a 1-2-1 code. I had checked the AMM & must have induced the 1-2-1 along the way.

So that makes my problem not so special - it's simply a no-start, with all the usual suspects. I do have a good spark, but after cranking a bit, the spark plugs are dry. So it's a fuel problem and there's lots of good (?) advice here about diagnosing that. I'll go read it and be back if necessary.

Thanks again.

I'd start with pulling the tank pump fuse (#4 on your car), and using a jumper wire (or paper clip) to jump either side of that fuse holder to an always on circuit (fuse 6), and verifying the two pumps both run when they should.... this is a test you do with the car switched OFF. see the first part of this page, In the Tank - 240 Volvo Tank Pump and Sender .... if one of the pumps doesn't run when you jumper power to the corresponding side of fuse 4, then you probably have a bad pump. if they both run, then its time to check the fuel pump relay, which is a white relay behind the glovebox.

Pierce - thanks, saved me some searching. The main pump runs, but the tank one does not. There is a small spark when testing the tank pump, but no sound. Next I'll do a voltage check at the tank - anything to delay having to go into the tank <G>.

Stepping back a bit: this problem was definitely weather related - worse in wet weather. It doesn't seem like the weather would affect the in-tank pump itself. Is there something else that would more likely be affected by the weather?

Thanks,
Bob

Oh, wait ... the only thing between the fuse and the pump is a couple of connectors. I guess that there could be corrosion, but it's looking more like the pump itself. Sigh

The in tank pump becomes a problem when you are less then a half a tank of gas. If the pump is submerged the main pump should be able to pull enough to start and run the car. So before you go to pull it make sure the tank is above the half way mark. If it still doesn't start then there is another issue going on.

I pulled the connector at the tank & applied 12v to the pump - nothing, not even a small spark (the small spark at the fuse was the Lambda current). Also, a ohmmeter test shows open.

So, a 1/2 full tank test might show that there's another problem, but I do know that the pump is bad & I'll replace it.

i dunno if this is still true, but there was a large number of 3rd party off-brand tank pumps that were wired backwards such that they sucked rather than pumped. that article in cleanflametrap mentions this, i believe.

The pump is out - if only they had made the opening 1/2" bigger it would have been so much easier. On the bench, the pump works fine, but I guess that it can be intermittent.

cleanflametrap says that the Airtex E8778 is his pump of choice. As of Dec. 2015. Anybody have any reason to think that it isn't still true?

Wrapup

The new pump is installed and the car is running. It was raining today and I had the same ole problem of it being reluctant to pull away from a stop. Very sensitive to how much throttle is given - with very light throttle it is OK, but hesitates & misses with more.

So, the "won't start" problem is fixed, but I still have the original problem. I was sure that they must have been the same problem, but they weren't. I'm off to do more searching, thanks for the help.

Bob

air leaks in the intake path can do that, anywhere from the MAF to the manifold/head interface. the plastic bellows can have cracks, the rubber tubes that go to the idle air controller, etc.
.

did you confirm condition cap/rotor?

Would that be affected by rain? This only happens when it has rained (doesn't to be raining at the time). I assumed (!) that it must be an electrical problem to be affected by rain.

Thanks,
Bob

I did and they look good. There's not that many miles on them. Of course, looks and miles are not conclusive, so I'm not dismissing the idea that these are the culprits.

Thanks,
Bob

i guess there is one way to find out! also, it's not unheard of that the wire between the coil and the cap can be partially compromised as well...you might try getting out there under the hood at night with the engine running and spritz some water around to see if you can create any 'fireworks'.

There's been quite a bit of rain, so I took a test drive and it was much worse than ever. I got out a hair drier and put it on the coil - no help. Then I put it on the cap & it was fixed! Just to be sure, I spritzed the cap to try to recreate the problem & it was still OK! Back to square one.

I guess that it was something else that got dried out by my driving 1/2 block & coming back. I'm gonna' try spritzing some other possible parts & see what happens. The ECT sensor 1st.

no fault codes on the OBD-I diagnostic block? not all the codes light the check-engine light.

Right - no codes for either the ECU or EZ. I shoulda' mentioned that.