94 lesabre stalling

[justn]

My car stalled out randomly twice and the service engine light came on, so I took it to the shop, and they said the scanner came up with the code for the egr. Mechanic said the egr can't stall out a car, but I've heard that it can. Can someone tell me which is right. Also, where is the egr and can I test and replace it myself, and would this also cause the car to studder/hesistate when pressing the gas. This doesn't happen all the time and the fuel filter has been replaced. Car has 253000 km, and its a 3.8L v6, and it does start right back up. Not sure what else to tell you because the mehanic tried tapping on parts to see if stalls but it didn't. Would like to get another year out of it without spending much, may be a dream I guess

Thanks for any help.

[abdullahadam]

we have simialr problems with our 1994 Buick LeSabre.

If you press too hard on the gas, it stutters (usually around 90km/h or more though)

Sometimes, it stalls with all the lights turning on (volt/service engine/oil) and we just have to turn it off and back on again

Sometimes, it doesnt want to start, have to try 4-5-6 times to get it to start and it finally works

[Bassasasin]

abdulahadam's car sounds like mine. Stalling out and runs after 2 minutes.. After alot of troubleshooting I ended up blindly changing the CPS Crankshaft position sensor.
I troubleshoot them now by cooling them with water. It is located behind the harmonic balancer wheel at about the 3 oclock position.

The misfiring when throttling up can be plugs or fuel starvation either by low flow, vacuum leak, coil packs, and other items.

The EGR Exhaust gas return valve returns exhaust back into the intake when the throttle is open at higher RPMs to get better gas mileage.
EDIT.. not primarily to get better gas mileage but to reburn of Nitrous Oxide emmisions. The engine is designed with it operating well.

Good Luck

[vrmlbasic]

?? I thought the EGR was designed to reduce emissions by sending the exhaust back into the engine and burning off more combustable elements, decreasing "harmful emissions" at the expense of performance.

[Bassasasin]

Your right.. By definition it reduces Nitrous Oxided by reburning is its primary function. But the engine depends on it working and mixes accordingly.
Glad Im not a Moderator.

Thanks.

[abdullahadam]

Very nice, thanks for the advice regarding my 94 Lesabre! 280k km and going strong!

[justn]

Thanks for the info. Bassasasin, how are you troubleshooting by pouring water,assuming small amount, is this to see if it will stall or to see if it will restart. Never had a problem restarting, always on first crank.
Abdullahadam, so did you replace anything or you just living with it. I am always on the highway so if it stalls could get a little dangerous.
So, could the EGR actually stall out the vechicle if not operating properly on the highway.

[Bassasasin]

CPS crank sensor on mine would fail when hot and I would pour water on it when it stalled. I started doing it at a service station with a water hose and copious amounts, and then loaded a gallon jug. I was on a long trip away from services through rual farmlands trying to get home to better resources. When it rained it would never fail.

The EGR may stick open, not sure if stuck open it would stall if you were comming up to a stop and it was still open.

Often electrical parts can be either cooled or warmed to troubleshoot if temperature seems to be a factor they can be identified. Such as an ignition module that only runs after warming up. The old HEI modules had sensors that would get hot and back then I would use freeze spray for electronics to determine their problem and get the car to run.

Im also wondering if the EGR has a sense for temp or just valve functionality, tossing the codes to your PCM.
Perhaps a Moderator could comment there.

Did you find the EGR? Its on the front drivers side of the motor with a conduit type tube from it to the intake.


Good Luck

[abdullahadam]

so far i have just lived with the problems..

strangely it stalls only when i am either driving very slowly (about to stop at the lights) or just started driving from a stop (at the lights), so never stalled on the highway


Abdullah

[Bassasasin]

EGR stalling... I talked to my GURU and he said "Yes the EGR if stuck open can cause the engine to stall if you have let off the throttle" . It opens up up under more open throttle positions and at warmer engine conditions.
If its sticking open it will cause the engine to run leaner or stall.

If the engine violently cuts out at speed then I suspect something closer to the Crankshaft sensor. Not the EGR.

Also stalling or missing at low throttle settings may be a dirty intake throttle area. Consistent stalling may be a vacuum leak.

Vacuum trivia:: Metered vacuum is environmental vacuum, theres a difference between intake vacuum and airflow vacuum since as you let off the throttle the engine pulls a higher vacuum but that is on the engine side of the butterfly throttle valve.



Good Luck

[justn]

Just an update to where I'm at, I decided to try and drive the car again and pay a little more attention to whats happening. I ususally drive on the highway and I noticed that it seems to drive fine while driving but when I slow down to the off ramps thats when I noticed its trying to stall because I see all the gauges bouncing, this is when it starts to shake also, sometimes it stalls sometimes not, seems fine in the city. Could this have anything to do with the tranny, and also I will be cleaning and checking the throttle area when gets a little warmer hopefully this week, anything else I should check or clean, and no codes were on the scanner.

Thanks