Stalling and Engine Light

[smithpl]

I have a 95 Transport that has been back and forth to the garage about 4 times in 2 weeks. The van is stalling and smells rich when running; the engine light comes on intermitantly. We have replaced the computer and the O2 sensor on the van twice now and the computer continues to tell us that it needs more fuel (according to the computer codes it is the O2 sensor). Since we seem to be treating the symptom not the problem, does anyone have a suggestion on what we might try next? Mechanic is suggesting the fuel injectors or a fuel regulator/control module (if this is the right term)?

My bank account and my wits are about at their end, looking forward to some guidance.

[LMP]

What engine is this? Stalling and engine light that comes on and off makes me think of the EGR valve stuck open : sure you do not have a code on this?
Injectors do not fail all at once on a sudden: there are six and I would not risk a penny on that as the solution to THIS problem.

[smithpl]

I have the 3800 engine. I appologise in advance, but TLA's (Three Letter Acronyms) are not my strong suite in automotives. What is the EGR? I couldn't tell you if I had code 100% for this, I was only passing on information from my mechanic. I just got it back today again for the same thing and this time they couldn't find anything. These intermitant problems are frustrating and very difficult to diagnose I am learning.

If we continue to have this problem with it; I will mention the EGR valve to my mechanic.

Thanks,

[LMP]

OK EGR is the Exhaust Gaz Recirculation. This takes part of the exhaust gases and returns it to the intake manifold for s second pass. This is done by a 3 section valve on the 3800 ; each section is moved by an electrical signal. the computer may require one,2 or 3 sections open. On mine, one section never opens and depending on the engine load, temperatue and peed condition,The funny thing is that when the conmputer requires 1 or 2 sections to open and not the section that is inoperative, then is everything is "AS REQUIRED" and the check engine light does not light up. If the damages section is required open , it will not open and then CHECK ENGINE light comes on. So the check engine light goes on and off randomly .
In my case, since the damaged valve is blocked closed, there is no unwanted stray gaz recirculation and I have absolutely no incoinvenience in oiperation. However, when one section is blocked in the open position, then there is stray exhaust recirculation even at idle and this may stall the engine and because the engine looses RPM, the computer adds more fuel hoping to gain RPM and this produces the rotten egg smell.

[LMP]

Oh yeah... the valve is very visible just at the front of the engine a little on the driver side, covered with a plastic cap and unhappely, it is expensive, more than C$250 probably.

[gm-andy]

It sounds like youe exhaust is blocked. That rotten smell is probably the cataylic converter. That will give you a rotten smell. Just because the computer thinks its the 02 sensors doesn't mean to replace it. Something is wrong in the exhaust stream. It won't talk to the computer if the cat is clogged because it is right before the converter in the exhaust manifold. Vechiles made in 1996 and on have at least two 02 sensors. 1 before the cat and 1 right after the cat. These obd11 vechiles are much easier to diagnoss problems with the cat. With a vacuum guage, you will see a plugged up exhaust.

Hope this helps..........

[richtazz]

I would go with either the prior mentioned EGR valve, or a leaking fuel pressure regulator. Neither part is too labor intensive, and a Delco EGR runs $169. The fuel pressure regulator is mounted at the fuel rail inlet, and could be leaking from the vacuum diaphram. It runs about $95 for a Delco part. I work at an AC Delco distributor, if you can't find the parts at a reasonable cost, let me know and I can ship them to you UPS at the prices above plus shipping.

[dorkdriver2]

Can anyone tell me what type of computer (OBD1 or 2) is on the 95. My manual says it's a 2 but it has the old style diagnostic plug which is missing terminal B which is needed to retrieve trouble codes. If it is an OBD 2 model, I can't plug in the newer scan tool because it's the old style plug. Does anyone have any answers.

[richtazz]

95's have a hybrid system. Locate a repair manual for your vehicle and it should tell you the proceedure for pulling codes. Look on the emissions sticker under the hood, at the bottom it will say whether it's obdI or obdII

[smithpl]

Thanks for all the advice; I have replace the EGR valve, the TPS and I have put in a new dealer computer instead of a "no name" CPU. Although I am no longer stalling, the light continues to come on and off on the dash, apparently the pig tail ?!? is very corroded and fell apart in my mechanics hand, we have put it back together with bubble gum and duck tape (just making it work) until the part comes in sometime this week. I am really hoping we are down to a bad connection with some part.

On an interesting note, when the TPS failed, it almost killed my wife. She was crusing down the road when the thing seized and the whole van went dead. It was like the entire powertrain stopped suddenly and she came to a grinding halt. She said it was like she was in an accident except she didn't hit anything; she was also very glad to have had her seatbelt on when it went.

I am hoping this is the last of it, the TPS has set me back about $300.00 cad on top of the $1600 I have already dumped into the van. Time for a new car I guess, this thing is nickle and diming me to death.

[LMP]

TPS...??? Throttle Position Sensor ?? Did that thing cause such a violent deceleration or do I miss the point?

[smithpl]

Don't know enough about how it works to say that for sure it caused the incident. I wasn't there so I can only relay what I was told and what the problem turned out to be after my mechanic limped it into the garage. At this point in the life story of my van, I wouldn't be surprised if there is something else that is broken or starting to break that we have just not been lucky enough to find yet.