95 silhouette stalls

[bbaz]

Greetings,

Have a 95 Silhouette with 125K miles.

I purchased this car about 5 months ago for a road trip.. I have always been a big fan of the GM 3.8 engine..

Anyway this van stalls, would also stall while driving on the expressway. Service engine light was on, scanner said O2 sensor had that replaced and the stalling problem got worse. after this NO service engine light and no codes in history. then was told needed a tune up, replaced plugs and fuel filter wires looked ok still stalls. Next replaced the ignition module still stalls.. Sometimes the engine will run fine for 10 min or more then stalls. Also changed ignition switch. During all this we noticed that the intake gasket was leaking bad had that replaced still stalls. Thought problem might be cam sensor but mech says he checked the sensor and it is fine. Inspected wire harness on engine thought we found some crimps in wires but no change still same stalling issue.
Noticed that when car is connected to scanner just before it stalls the scanner loses communication and restarts.. scanner loses communication constantly. Car runs better after all this work but still stalls... While stopped at traffic light sometimes fine then sometimes the RPM up and down then stalls. While driving sometimes it feels like the engine revs and the service engine light will flicker. Scanner shows no codes or history of codes..

Overall the car runs better after all this work but it still stalls...

The mech is a buddy of mine so I am there when he is working on this but he seems kind of frustrated and is giving up.. I think maybe computer but not sure.. Any suggestions. Would like to keep if I can figure out this problem.. Any suggestions appreciated

Thanks

[bbaz]

Also I did change the cam sensor. Didn't resolve problem still stalling..

[Blue Bowtie]

If you haven't done so already you can disconnect the battery, remove, and inspect the connectors at the PCM. IIRC these vehicles had the PCM in the RH kick panel. Check the connectors for moisture and corrosion. Sometimes un-seating and re-seating the connectors will solve some intermittent connection issues. I'd also suggest checking the main power distribution and ignition switch.

[Blue Bowtie]

I know the '96-UP U-Body FWD vans had the PCM under the hood, and have had problems with those PCM connectors in the past:

[bbaz]

I think the mech checked the connections.. But i will double check..

SES light has been coming on now for the past few days.. Pulled codes the other day.. one was O2 sensor LOW.. not sure what that means but the O2 sensor was recently changed.. the other code was something about Fuel LEAN. the SES light would come on and off. cleared codes and the car was stalling real bad almost at every traffic light and also while sitting idle.

The SES light came on again and stayed on, the car has not stalled since. SES light has been on for a couple of days now.. Havent had the chance to check codes yet. Will post codes when I check them..

[Gasparr1]

hi, well i had a similar problem as you. i replace several sensors and nothing changed until a friend told me that the issue is the MAF sensor. i cant believed this but i replace this sensor and now my truck havent failed since 4 mounts ago..

[bbaz]

Just a quick update.

Still was stalling real bad my mechanic pulled SES codes and there was O2 sensor code. I have had this code ever since problem started and even had the code when O2 sensor was replaced. My mechanic was thinking it might be a defective O2 sensor so he unplugged the sensor and suggested I drive it with O2 sensor unplugged to see if there is a change. Its been about a week now and with O2 sensor unplugged the car is running 95% better no stalls. Going to install another O2 sensor and see what happens will also inspect the wiring connected to the O2 sensor.. Hopefully we found the problem.. Thanks I will let you guys know what happens after the new O2 sensor is installed.

[merc81]

I posted a thread on changing out the upper and lower O2 sensors a few months ago. I had to change them again because of the stalling problem and SES code you mention. I got the first set from rock auto, but returned those (never got any refund fyi) and got the 2nd set from Napa.
Never stalled since.