OT: Van Still Running Rough

[JB in Co]

Up-date: 1995 Chevy Astro Van running rough with check engine light on. (Showing code 32). Did a tune-up (plugs, plug wires, dist. cap and rotor and replaced the EGR valve). Also oil and filter change. Runs better - Check engine light does not come on, I think that problem is fixed, but still rough and feels like it is missing. Took it to the local Chevy dealer, they don't know, said it might be a fuel injector problem, they checked out #1 cylinder, compression good. They wanted to pull the valve cover($197) and look at #1 cylinder. I didn't get a good feeling about that, said NO and left, after a $99.99 fee for the diagnostic test. I then put BG44K in gas tank to clean jets and BGmoa in engine oil to clean out lifters, etc. Hope this helps, don't know yet. Any other ideas or suggestions would be greatly appreciated, as always. Thanks in advance, JB (sorry for the long post)

 

[bobs old iron]

the bg-44 might help smooth it out, did you change fuel filter, the fuel pump may be weakening, i don't see where taking off valve cover will do anything, need to pull head to look inside cylinder [typical dealers] also check cat and muffler for back pressure. not knowing mileage, possible. other wise you cover just about all angles of what you have/needed done. don't be sorry, most people don't put half as much info and want to know whats wrong. since you put the bg in, take it on the road and give a long run at 60++ mph to clear out any carbon build-up and clean injectors.

 

[oldtanker]

Son had that problem with a Buick, and injector was bad. That trouble could be a weak fuel pump as was stated too. Gas dribbles in instead of spraying so you get a poor air fuel mix and you can get the same dribble from a plugged fuel filter.

I'd find another dealers, yours sounds kinda sad.

Rick

 

[JB in Co]

Bob, thanks. It has 142,000 good running miles on it, I replaced teh fuel filter last week no help and it has a new fuel pump (last year). I'ii take it out tommorow on the highway and blow the carbon out. JB

 

[JB in Co]

oldtanker, thanks, new fuel pump last year, but, it could be it again. JB (Changed fuel filter last week).

 

[lha]

Good old Seafoam does a good job of cleaning fuel system.You can check fuel pressure,maybe even before and after the regulator,to see if you have adequate pressure to the injector.If you have throttle body injection,you can rebuild just like a carb,I did on my Nissan truck,and it did a lot of good.---lha

 

[working dog 7]

May be clogged cat converter? had 1 on a charger had me pulling my hair for a while .good luck.

 

[Sphere]

I'd pull the cowl ( intake) and have look atthe fuel rails, They are plastic and crack. That spews gas even when shut off and it fouls a plug. Then you get to repeat the egr valve sequence yet again. The rails/ spider aren't cheap either, IIRC 400 a side.

Did ya swap a new 02 sensor in when ya did the new egr?

 

[JB in Co]

Sphere, I only changed the egr valve. JB (o2 sensor?)

 

[ooops]

Pull the distributor and replace the distributor gear. Have changed many of them because of rough idle. The gear will be "apple cored".

 

[Sphere]

THe oxy sensor is down on the exh. pipe before the cat conv IIRC, it takes a special sensor wrench also , or you can wrestle it the hard way. It reads the exh. gas and sends word up to the computer to adjust rich/lean and idle rpm. There is no idle adjustment on them. If the 02 sensor is still carboned up from the previously bad egr , it will affect the computer communication to the fuel delivery system. Or it affects the mass air sensor which will be confused too.

Is your exh. pipe still black and fuzzy inside? If so, you still have raw fuel seepage and fouling a plug or 2 , usually on one bank, I never saw both sides of the spider go bad at once. I know its hard to get to the plugs , but I'd pull em one by one and see how black they are.

 

[Dunk]

(quoted from post at 00:51:10 04/06/11) Good old Seafoam does a good job of cleaning fuel system.You can check fuel pressure,maybe even before and after the regulator,to see if you have adequate pressure to the injector.If you have throttle body injection,you can rebuild just like a carb,I did on my Nissan truck,and it did a lot of good.---lha

SeaFoam is the ONLY "snake oil" I have ever seen that seemed to actually do anything, and I will buy more when needed.

 

[JB in Co]

Dunk, thanks, forgot about SeaFoam, will try it if the BG44K dosen't help. JB

 

[JB in Co]

ooops, thanks, I checked the play in the distributor shaft, it has just a little movement. I am just about to my limit of ability here, and ready to take it to another shop. I will have them re-check the distributor. Again, thanks, JB

 

[JB in Co]

working dog 7, thanks, I'm not sure how to check for a clogged cat. converter. JB

 

[JB in Co]

Iha, thanks, I did forget about good old SeaFoam. I'll need to have the shop check the fuel pressure as I do not know how, and not sure if I have throttle body injection. I'm at my mechanical limit with this problem and about to take it to another shop. (or to the junk yard). JB

 

[JB in Co]

Sphere, again, thanks. Before this problem the exhaust pipe was real clean, now after I have changed the egr valve and tune-up it is black. Exhaust fumes have a strong gas smell. To me, it seems to be running rich ?? JB

 

[Sphere]

It probably isn't RUNNING rich, it is flooding a cylinder or 2 with raw gas seeping in and not fully burning it off before it heads out the exh. Classic sign of the fuel spider rail leaking. I'm betting a google search will turn up hundreds of examples of that, it is a very common issue in the mid 90's 4.3's . Do you have the VIN handy? That will determine if ya have the vortec or not.

Any muffler shop ( that you can TRUST , good luck with that) can drill a hole in the cat.con. and insert a tube that measures whether the cat is plugged or not. They then , if good, weld the hole shut. That will cross that off your list of possible issues. But keep in mind, even if it is OK now, if you don't address the richness, you WILL plug it up sooner or later.

Start pulling plugs and look for a black one..there is your side that is leaking.

 

[JB in Co]

Sphere, vin # 1GCDM19W9SB111124 and when the dealer ran their test, last week, they were interested in #1 cylinder (compression was ok, new spark plug and wire). I re-checked three different plugs yesterday and #1 was a little sooty, but not bad. ( I probably can't get any muffler shops around here (Denver area) to drill in a cat converter ) they just want to sell me one.Again, thanks JB

 

[Eman]

Is it a dead miss or just a rough idle? Do you feel the miss under load or all of the time?

I'm not sure which engine you have. The 4.3 used different injection systems. There was a throttle body injection and 2 different "Vortec" injections. The Vortec types had their problems with carbon and sticky EGR valave. The first style Vortec had a spider type fuel injector under the plenum that had the regulator built in it. It was 1 injector with 6 nozzles. The regulators leaked fuel in the plenum and the fuel supply lines also leaked and cracked. This style injection had a standard dist and the timing was adjustable. The newer Vortec injection had 6 individual injectors inside the plenum and the injectors would get sticky. This system had an empty dist and the timing was not adjustable, all the dist had was a cap and rotor.

 

[JB in Co]

Eman, thanks. It is a miss, like one cylinder is not firing right, and the idle is not rough not smooth. It is worse under load and when starting to accelerate. (shakes alot then smooths out at higher rpm.) JB

 

[Sphere]

The "w" in the V.I.N. tells me you most likely have the exact same issue I was having with not one, but two of mine. You'll fine the problem under that big alum. plenum. I'd bet my left nut on it.

 

[JB in Co]

Sphere, Thanks, I think you are right on (Fuel injection problem). I replaced the map sensor today (no help). I took it over to a local small auto repair shop today and he came out and looked at it, says it is missing on one cylinder, wants me to bring it in so he can diagnose it and give estimate. He thinks it is fuel spider injection issue and will have to remove the alum plenum. (Vortex engine). (I can see this is a tight space to work in, is the injection system hard to repair? JB

 

[Sphere]

The hard part is getting TO it, the parts are plug and play.
Best of luck to ya.

 

[Eman]

Get a spray bottle, like an old windex bottle. Have someone powerbrake the van while you lightly spray the spark plug wires. Start at one end and work your way up. If you can make it miss you have a bad plug wire. This is the poor man's scope.
I'm betting you might have a cracked spark plug insulator if it's not a wire. Those plugs can be rough to get to and it's easy to crack one putting it in. Be sure to put some dielectric compound in the spark plug boot when installing them.

 

[JB in Co]

Eman, thanks, the spark plugs and wires are new, installed last week. JB

 

[JB in Co]

Sphere, Thanks for all your time and help and good advice. I'm not sure I'm ready to tackle the injectors yet. I'll post an up-date when problem is resolve. Again, thanks.JB

 

[Eman]

Did it do the same exact thing before they were installed? I've had bad new spark plug wires and I've broken a plug installing them.

 

[JB in Co]

Eman, yes, it was the same before and after I installed the plugs, plug wires, cap & rotor. JB