Thread: Still stalling -have replaced cam sensor, crankshaft sensor & fuel pump switch

I am new to this forum and I'm sure there have been many questions about this issue but my car has been in the shop for this issue 3 times and it is still happening. It is a 2004 Grand Prix with about 190,000 k. In September I had been running errands and car stalled when I went to accelerate after stopping at a stop sign. It started again right away but only got about 100 feet and it stalled again and would not start. After about 20 min, it did start again but I didn't get very far and it stalled again. By this time the tow truck had arrived and I had it towed to the shop. They replaced the air filter and cleaned the mass air flow sensor. The day I picked it up I was leaving on holidays for 2 weeks so it wasn't driven. When I got back, I drove into the city (about 30 min on the Hwy) and then through downtown traffic for about 15 min. After stopping at a red light, upon acceleration it stalled. Started right back up but only got 30 yards and it stalled again and wouldn't restart. Had to tow it to a mechanic close by. They replaced the crankshaft sensor and then let it run til the engine was good and warm and drove it around the block a few times to make sure it would keep running. Everything was fine and I made it home in what was now rush hour traffic on the hwy. Everything was fine for about 3 months. Then 2 weeks ago, I was doing about 80 km/hr and the engine just suddenly quit. I managed to glide into a driveway and stop. Car restarted and I decided I should just turn around and head home. Backed out the driveway and got about 100 yards and it stalled again and wouldn't restart. Had it towed again to the shop. The were stumped and couldn't get it started for a couple of days. The checked fuel pump, replaced the cam sensor, replaced the crank shaft sensor, replaced the fuel pump switch and said the busbar was loose so they tightened it up. They weren't really sure what the problem was but it was now running. The day after I picked it up, I got about 1/4 mile, stopped at a stop sign and went to accelerate and it stalled. It started right back up but I decided to turn around and go home. Stalled again when I went to back up but again started right back up. Got home, pulled in front of my house and sat in the car and let it idle for a bit. It stalled. Started again right away. Put it back in my driveway, let it run for a while and revved the engine a bit, it stalled once but then seemed to keep running for quite a while. Decided I'd drive around the neighbourhood and see what happens. It ran fine. Drove it back and forth to work all week (only about 4 kms) and around town to run errands and it ran fine all week. Today went to run some errands and on my way home it stalled again this time while driving at a low speed. Pulled over and it wouldn't start. Since I wasn't far from home and car was parked on residential street I figured I would just get a ride home and come back in an hour or so and see if it would start. It didn't. Called the tow truck and asked them to pick it up when they had some time. About an hour later the tow truck driver called and asked what had happened. I told him and he wondered if it could possibly be the security system (although no lights or warning messages had come up) and asked if he could stop by on his way to the garage to get my keys. He pulled up with my car attached to the truck, I gave him my keys and it started right away (without doing the trick to override the security system). I don't feel safe driving with this problem especially when it happens at high speeds. During all these instances, there has never been any lights that come on. Any suggestions?

Is it still the stock tune? Mine was doing that when the tables for my map sensor was wrong. You might check for pending codes mine wouldn't set off cel light but i had a pending maf code. One of the more experienced guys here may have a better answer for you. You might pm billboost hes good at trouble shooting.

I think the first thing to do is to data log and see just what exactly is going on, I have seen small "datalogger" that plugs in the OBDII port, and you leave it there all the time until the problem has re-accord, then you download the data an inspect all the parameters. This should give a direction to go with solving the problem.

Yes selliott it is stock tune. Here's where we are at now. I took it back to the garage on Monday. They left it running in front of the shop and it stalled twice. Each time they checked for codes but there weren't any. They don't know what the problem is. They were going to get a Mass Air Flow Sensor and a ECM from a wrecker and try those so I brought it home to await the parts. The next morning it would not start at all. Parts finally came in 3 days later and they came and towed my car to the garage. Tried the MAF sensor - no change. Put the ECM in and had it reprogrammed - still won't start.

Does it shut down quickly, like you shut the key off? Or, does the engine rev down slowly (as if it is out of gas, but still trying to run)?

Also, do the gauges drop off quickly? In other words, does the tachometer show 0 RPM before the engine has stopped running altogether? Or do the gauges continue to work accurately?

It shuts off quickly. I don't really have time to notice all those things as I'm trying to get off the road without any power steering or power brakes working. When it shut off while doing a fair speed, I felt a slight stutter which made me look at the tach and it was quickly dropping as if I had just turned the car off.

Originally Posted by Fivefingerdeathpunch

Or the harness to the crank sensor is becoming faulty.

This is the next thing I'd look at.