Random off idle misfire / extreme lean conditions sometimes

[pur3vil]

Hey guys. I bought my 92 back in October. Previous to my owning it sat for about 3 years. No biggie. Water pump went out, replaced it easy enough, trans went out, replaced it, PS pump snapped a shaft, easy enough to replace..

The thing that's been buggin me though is the ignition / fuel issues I have. Even when the van is running right, I get a misfire / skip comign off idle with a very light load, If I let up it will go away, or if I push it harder it goes away. This is pretty predominate, it doesn't really matter if it's warm or not, it doesn't really change. Some times though rarely it won't do it at all. That's issue number 1, but isn't near as devastating as this second one.

This has happened previously and and it doesn't stick around sometimes. Yesterday this became a very very large problem. One day after filling my tank it acted like I dropped a cylinder and was runnign stupid rich skipping, misfireing, generally running poorly. And the problem cleared itself up within 10 minutes or so. During this time it was flooding so miserably I had to hoold the pedal to the floor to get it to start and when it did it didn't want to run at all. This has only happened once that I can think of right off.

This next problem happens way more often. We've had soem pretty disgusting weather / road condidtions last few days or so and it's been pretty dominating. It is running lean. Too lean for any vehicle to run. Idles like it has a MONSTER cam in it. On takeoff has a MONSTER hesitation that generally takes 80% throttle to push through, and then it's fun cause the van will take off and on these roads go sideways and all sorts of stuff... fun in an AWD granted but not right... If you let it sit and idle sometimes you will hear it it just clears it's throat and idles perfect.. and will run right for a minute or two then go back to the hesitation.. Adn it will do this for a while. It ran this way with the lean conditions and hesiatation all morning yesterday, ( it's drove abotu 4 hours a day from 2am to 6am or so ) and then for the first 30 mins to an hour today and then cleared itself up and hasnt' returned. As matter of fact it's running better now then it has in a few weeks... I'm personally mind boggled by this.

I went to my local store and borrowed their code checker ( my MIL is burned out I think, doesn't come on with the key ) I accidently cleared any code that may have been stored before reading them originally.) I havn't ran them today yet but will shortly to see if soemthing has popped up.

The latter of the condidtions are the most devastating as I have a certain time frame I have to complete my work in the morning and this slows me way down, so I haev to fix it. It acts liek a super weak fuel pump during this time. all the symtopms are there. At the same time it was happenign though I was driving through alot of slush and big puddles.. today the roads are alot better. The last time it ran this way I remember the roads were pretty wet too... What could possibly be getting this wet to make teh engine run this way. I was thinking distributer but usually they dry up fairly quick, and this wasn't going away. Is the water / slushy crap shorting or causing a partial short somewhere under the van causeing the fuel pump to drop voltage thus droppign my fuel pressure? I'm at a loss.

When the van is running other then the off idle hesitation / skip it runs fantastically and is a blast to drive, Especially when it's nice and slick out, the all wheel drifting up a hill is fun. And pullign AWD scoobys out is fun too. I generally laugh and remidn them it's not their typical minivan.. haha..

Any help would be appreciated this is my money maker and need it on it's feet 24 / 7..

[LiftedAWDAstro]

First thing to do is cap, rotor, plugs and wires. Next you need to pull the EGR and make sure it's clean. A screwed up or plugged EGR will give the same running/idling conditions you have.

Oh...Welcome!

[lockdoc]

I'm with Dean. I just went through a very similar situation with my kids 92 van. Turned out to be the distributor cap.

As for the miss off idle I had a 92 with V8 that did the same as you and that turned out to be the EGR.

[pur3vil]

Thank you guys for the imput. I'll do the following and report back.

[1Gary]

I suggest you use a screened replacement gasket for the EGR.You find them on the help section in your local parts store.

[SoCalli V8]

You should begin with a Quality tune-up first with AC Delco plugs that are the correct # for your engine, and then fit Hi Quality AC Delco cap, rotor and wires. Chevy engines run crappy when you fit strange..... >> Champion,(European Jaguar) Bosch,(German BMW, Mercedes) or Autolite (Ford) sparkplugs or cheap ignition components, In a Chevy engine.

[astrozam]

I had an EGR causing very similiar conditions on my 95 on start up, after several hundred dollars the new EGR fixed the problem nicely ( not to say that you may not have other issues with the van as mentioned in the earlier responses ) however the van is now off the road for good with that new EGR looking for a new home

I'm pretty sure the 92's were the 1st yr of the W engine which is what my 95 has as well.

Are you Stateside or in Canuckistan?

[pur3vil]

I had an EGR causing very similiar conditions on my 95 on start up, after several hundred dollars the new EGR fixed the problem nicely ( not to say that you may not have other issues with the van as mentioned in the earlier responses ) however the van is now off the road for good with that new EGR looking for a new home

I'm pretty sure the 92's were the 1st yr of the W engine which is what my 95 has as well.

Are you Stateside or in Canuckistan?

North Fricken Dakota... lol.. And yes the 92's we're the first W codes..

You should begin with a Quality tune-up first with AC Delco plugs that are the correct # for your engine, and then fit Hi Quality AC Delco cap, rotor and wires. Chevy engines run crappy when you fit strange..... >> Champion,(European Jaguar) Bosch,(German BMW, Mercedes) or Autolite (Ford) sparkplugs or cheap ignition components, In a Chevy engine.

I usually run Bosch Plat ( the original's ), but I've heard GM was particualr to Delco ( being GM owned and all ) ...

I suggest you use a screened replacement gasket for the EGR.You find them on the help section in your local parts store.

Never heard of it I will look for one when I get to it.