Thread: GTP engine issues please help!!!

Hey guys!

Having some trouble with my GP and have run out of options and ideas as to where to look. Some background on the car.....bought it in july of '11 and so far it has been a good solid car(came over from an Audi) but recently have begun to give me problems. It would die on me in the middle of driving even approching 80 mph would shut off and after a minute or two would start right back up. I had concluded that the Crank Position Sensor had gone bad. Which brings me here. I will be honest, I followed the DIY found on the forum and all went well pretty easy job. Now at first I didnt hold the flywheel as I tried to break the harmonic balancer bolt loose, and i dont know if I threw something off....but eventually threw some vice grips on the flywheel and proceded as the DIY stated. Within 24 hours of changing the CKP sensor I began having BIG problems. I had idled the car for about 45 mins while detailing the inside and when I finished went to fill her up and placed it into drive and as i pressed the gas noticed the motor chugging and making a hissing sound like opening a 2 liter bottle over and over coming from behind the firewall on the driver side.


As I drove to the gas station i noticed that as i approch 2000 RPMs the motor chugs and makes the hissing and doesnt want to accelerate. I also noticed that the boost guage on my DIC is boosting as if it is at half throttle under heavy acceleration. Had it run for codes and came back with P0102 MAF low, P0122 TPS circuit low, P0171 Bank 1 lean, P0300 Random Misfire, P0336 CPK Sensor 18/24x out of range,P1122 TPS circuit intermittent low, P1571 PWM circuit no freq./signal. Erased the codes and P0122,P1122, and P1571 came back. I have change out plugs and wires removed and cleaned the MAF, Replaced the TPS, Cleaned the Throttle Body and IAC Valve also replaced the Throttle body gasket. And to no avail i am still having the same problems as if nothing I have done has changed anything.


I have exhausted the search bar and come up with most of the information leading me to the work already done and I am unsure on what to do next. I know that there is a ton of experiance on here and I would really appreciate any feedback. I want my car back on the road and really want to get her running the way she was. Please Help!!!!!!


Thanks.

I would bet you have a vacuum leak of some sort somewhere. I had similar codes not that long ago and the rubber elbow that goes into the MAP sensor was cracked and leaking. That leak made the transmission act up as well. When you did the crank sensor, did you make sure to get that harness tucked away like it's supposed to be away from any moving pieces. I wouldnt dump a bunch of money in gaskets in hopes of a fix. Try diagnosing some more.

is there any possibility of me having thrown off timing or somthing when i didnt clamp on to the flywheel at first? correct me if i am wrong but the CPK sensor does communicate with the ICM?

what is a crank case relearn?

There is no way to mess up timing unless something really went awry or you changed it mechanically. Since the motor runs we'll rule that out. The CKP does indeed communicate with the ICM. You could try a relearn, that's a good suggestion. If you need to test the wiring to the CKP and ICM I can show you how to isolate it to see if that is the actual problem.

Deangtp that would be awesome if you could show me how to do that.

easyautodiagnostics.com go to GM-3.8. You will need a multi meter and some patience. I used this site and is very easy to follow. I would try the relearn first though. You can google it and probably find a result.

Deangtp that would be awesome if you could show me how to do that!

Thanks !!!

Wiring.

Harness for CPS runs right beside the belt.

Ensure it is still in tact.

Thanks Matt5512 I will be checking the wiring and the harness tomorrow. Have you ever heard of having to replace the entire harness? Just curious as to how difficult it would be to replace

Originally Posted by 03GTP38k

Thanks Matt5512 I will be checking the wiring and the harness tomorrow. Have you ever heard of having to replace the entire harness? Just curious as to how difficult it would be to replace

If you are talking about just the harness that runs to the cam and crank sensors, you could swap that out in a few minutes. Everything else, you should be able to isolate with the website I showed you. Something simple probably. Keep at it.

so i just cleaned the ignition packs and started the car. At idle the motor ran smoothly but i noticed that the distinct 3800 motor noise wasn't there, it sounded very muffled. I removed the O2 sensor on the down pipe and started it up and it seemed much better. Could a clogged cat be causing the issues as stated in my original post?

A clogged cat could make the car very sluggish, so it may just be that easy. I would take off the downpipe and take look.

Hey guys!

Just wanted to say thank you to all that helped me find the problem with ole' Silver Fox. Turned out that the Cat had become so clogged that it almost melted itself shut. luckily i had gotten to it before it did any more damage. Once again thank you. I am appreciative of the feedback and will try to upload some pictures later....It was pretty bad.

Glad you got if figured out!! Its nice it was something easy for ya.