Need professional help and opinions

**AaronAndroid** · 12-09-2015

I have no past mechanical knowledge and this is the first car i have ever owned, it is a 2000 grand prix gt 3.8 v6, 202000 miles and i am having a confusing issue where the engine will shut off while im driving and needs time to cool down before it will start again.

A little background on the issue i have noticed is that when applying constant pressure to the gas pedal, or when using cruise control the engine will shut off and when this happens the battery light will come on. Although i have found out that by pressing on the gas to gain speed and then letting off of it for a short period, by repeating this process i can get the car to run as long as i need it to without the engine shutting off.

I have put a good amount of at home work in on this car with the help of tutorials and a mechanic's help, and he is even stumped as to what the issue is. To date i have myself replaced water lines, brake lines, fuel pump, crankshaft position sensor, and harmonic balancer. The owner previous to me claims that he had the head gaskets replaced also.

Recently i figured id take it to Autozone to see if it would be throwing any sort of error codes but it didnt, and i was told i would probably need to take it to get a running comprehensive diagnostic test at a dealership or shop so they could graph any sensor performance for issues. Im just trying to look for an answer, help, or idea before i start dropping anymore money on something that might not be the fix.

I am glad to answer any more questions pertaining to the car if it will help.

**Fivefingerdeathpunch** · 12-09-2015

I'd maybe look into the harness that runs to the crank sensor or maybe even the new crank sensor itself. I don't know what brand you use, but aftermarket non AC DELCO units are known to fail right away.

**AaronAndroid** · 12-09-2015

I bought an ACDelco brand sensor, and was looking up preciously a way to use a voltmeter to test the plug and sensor itself. I also came across some mention of having to relearn the new sensor to the engine but that was only one article.

**Scottydoggs** · 12-09-2015

the cam crank sensor harness maybe cooked up. mine was ll brittle and cracked up. bare wire showing.

does it flat out stall? or does it fight to stay running?

**AaronAndroid** · 12-09-2015

It just flat out dies.

**Scottydoggs** · 12-09-2015

id pull that harness then. you can get its plug off with out taking the balancer off again. you need a pick to pull on the lock tab then pull it off. cam sensor is also rather easy to get to.

when you did the crank sensor did you tq its bolts to 13 fp?

and ever notice the tack dropping to zero while driving or right before it stalls?

**AaronAndroid** · 12-09-2015

When replacing the sensor i used a small angled socket wrench and tightened it down as tight as i could get it and couldnt use a torque wrench in the tight space.

Where is the cam sensor located? When searching for it online its always referenced as also being the crank sensor i replaced.

Also what do you mean by tack? If you mean the dials then yes, when it dies and im coasting to a stop when i press on the gas pedal the mph take a steep drop but come back up when i depress. I didnt pay much attention to the rpms though. My next idea was to drop it in neutral and have a small amount of constant pressure on the gas to see if i can recreate the issue without driving.

**Scottydoggs** · 12-10-2015

your issue maybe you made the sensor bolts to tight. theres a tq spec for a reason. did you take the balancer off to change it? if not you need to.

and the tachometer is what i meant, it ever drop to zero driving, then stall.

**AaronAndroid** · 12-10-2015

I did remove the balancer to replace the sensor, nothing mentioned a torque spec on the bolts for the sensor so i may have to look that up. And the tachometer only drops after the engine cuts out.

**AaronAndroid** · 02-02-2016

Small update, driving the car every day had made two engine fault codes appear. A P0401 and a P0453, could these possibly attribute to my issue? My next step is taking a multimeter to MAP, CKP, ERG, and throttle possition sensors.