95 Lumina dies suddenly at 50mph and at stop light

[Tracks]

Three weeks ago after filling up and driving around 50 mph, the car "jerked" and then just died. The volt light and ck engine light came on. I could start her back up again but she smelled funny so I called a tow truck. The garage could only find an error code w/ the EGR valve. (The EGR valve was replaced 1 1/2 yr ago.) No repair was done. Fast forward two weeks. She has since died at a stop light and at the base of the driveway, both without prior notice. The ck engine light has been on for over a year and they've never been able to find anything. When she dies, the VOLT light comes on as well as the Ck Engine light (if it wasn't on already). She also seems to hesitate some between 45 - 55 mph. There is also a faint gas smell when you start her up. The garage has had her for 3 days this week and has found nothing. Any advice?

[maxwedge]

Originally Posted by Tracks

Three weeks ago after filling up and driving around 50 mph, the car "jerked" and then just died. The volt light and ck engine light came on. I could start her back up again but she smelled funny so I called a tow truck. The garage could only find an error code w/ the EGR valve. (The EGR valve was replaced 1 1/2 yr ago.) No repair was done. Fast forward two weeks. She has since died at a stop light and at the base of the driveway, both without prior notice. The ck engine light has been on for over a year and they've never been able to find anything. When she dies, the VOLT light comes on as well as the Ck Engine light (if it wasn't on already). She also seems to hesitate some between 45 - 55 mph. There is also a faint gas smell when you start her up. The garage has had her for 3 days this week and has found nothing. Any advice?

Welcome to AF, 3.1 engine I assume? What has the garage checked so far, when it dies does it start right back up? How could they find nothing with the cel, no codes? Need lots more info here.

[Tracks]

It is a 3.1L. For the past year the CEL was on and they couldn't determine anything. They thought that it was just stuck as happens with most older cars. The only code that came through was when the car first died on me and then they referenced the EGR valve. This time nothing appeared. They drove her on several different occassions without any success and they allowed her to sit idle for several hours hoping to pull something, to no avail. A few sensors were checked but I can't be specific. They have no response for the hesitation between 40 - 50 mph either. I was basically told to run it till whatever it is, breaks completely. Each time she dies on me, I have been able to restart her without a problem.

The first time was different, however. We had her die at a red light. Attempts to crank her failed and we had to get her pushed until the tow truck came. The tow driver suggested trying to crank her which she did. He took 2 hours in arriving so she was pretty cold by then. We had him follow us and, sure enough, she died again about 10 mins later stopped at another light. No problems found by the mechanic except the EGR valve. She ran fine for the next couple of months and then did it again. This time they replaced the EGR valve. Ran fine for several months and then died yet again. Still no codes.

We replaced the battery Memorial day weekend (what a bear) but the mechanic ruled out needing a reset (or relearn) since they can't duplicate the problem. So far all they've gotten in codes is the last time we towed her and she showed the EGR got stuck and one other problem (can't remember what it was exactly but it was related to it). They drove her with the computer hooked up and manually operated the EGR valve and found no problems. Their speculation was that some crud had gotten stuck but dislodged since. Per their recommendation we ran some Seafoam addative through. Since that time she can be restarted without problem after dying. It's the increased frequency that has me concerned. On the upside they've charged us no diagnostic fees and are just as frustrated but the downside is no diagnosis

Getting to the point we're looking at a new(er) car

[Supergumby]

If I had to guess, I'd say you're looking at a DIS module.

The module performs two functions; fire the ignition coils, and send reference pulses to the ECM for firing the injectors. If the coil driver section goes out (or becomes intermittant with temperature), the engine will die suddenly, from loss of spark on all 3 coils. The modules 430 circuit(distributor reference pulse) can still function, causing the ECM to continue firing the injectors while cranking - hence the fuel smell.

The EGR code (on a 1995, it's probably code 77), is pretty common as well; there are three pintle valves that make up the EGR valve assembly, and the ECM checks the operation of the valve by turning all three of the valves on during extended zero throttle above (about) 50-55 MPH (like coasting down an interstate hill), and looking at intake manifold vacuum. If the vacuum remains high, the valve must not be working, so the ECM sets a code. However, 99 out of 100 times, the intake manifold passage has become clogged, removing the throttle body and EGR valve to clear it with solvent and a coat hanger fixes it.

Good luck......

[Tracks]

It has finally been solved. It turns out that the wire that connects to the Crank Shaft Positioning Sensor was laying too close to the Exhaust Manifold. The hotter the car got, the wire would fry thus shutting the car off. I'm still a little hesitant that this solved all of the problems with the car but for the time being, since removing the singed wire, she hasn't quit on me. Knock on wood. Thanks for your help.