Thread: FIXED!! Engine studder, tach drop, P1361 (video added)

I've been having a few issues with my '97 GTP. Last winter it happened a few times, and now that it's cooling off again, the problems is coming back and it's getting a bit worse. Sometimes, especially under heavier loads, I'll get what feels like fuel cut. Also, during extended periods episodes of the hiccups, my DIC will flash 0.0 constantly until I shut the car off. At idle, if it hiccups, I notice the tach drop to zero momentarily.

Last winter, it popped a code a few times related to the ignition control module not getting a proper signal from either the cam or crank sensor (I can't remember exactly). As of now, though, there are no codes stored, but it keeps acting up.

Anyone have any ideas what may be my problem?

Here's the vid:

tach dropping to zero is normally a bad crank sensor.

That's what I'm hoping is the only problem. Why would it seem to act up only when it's colder outside, though?

Just scanned it again. Got a code this time. P1361 Definitely related to the CKP sensor... Might just be time to replace it. It is the original with almost 140k miles of abuse.

Yup they are easy to do.

Looked up more code specifics and found nothing about the CKP sensor. It all points to the ICM, PCM, or wiring. Possible loose wire at the computer or bad ground?

For the cost and consistency, I'd go after the crank sensor first. It's the most common issue.

I'll pick one up and install it. I'll update when I get it put on.

Picked up a new ckp sensor last night and will hopefully get it on today after work.

One thing I noticed last night when it did its thing and the tach dropped, the speedo also started to drop rapidly, but didn't make it to zero before everything picked back up. Then, when I started to accelerate after that, the speed display on the HUD acted like I had lost traction and spun the tires up over 100, then resumed to normal (I was barely touching the throttle).

Okay, so the CKP sensor didn't help any. I did take the PCM apart and inspect it to make sure there were no bad solder joints and they all looked good to me. After re-installing it, I caught one hiccup and haven't had any other major issues since then. I can only assume that the problem was/is in the PCM plug or the first foot of wiring to it.

What do you guys think?

Where is the crank sensor located and hoe do you install it? I wanna change mines for preventative maintenance.

It's in the how to section of the forum...
http://www.grandprixforums.net/cps.php

Thanks dan

I got a video on the way home. It's real low quality, but you can still see what's going on sometimes. The HUD speedometer goes crazy while the analog one works just fine. The DIC also just flashes 0.0.

my 01 is doing something really similar. dont mean to thread jack but mine only does it from a stop at about 50% throttle. it jerks hard and the speedo on the hud goes wacky. i dont get the 0.0 on the DIC tho. i had it at the dealer to diagnose my EBCM as bad before my car started doing this and they told me my computer might be bad. i guess all i'm asking for is a little direction. fuel filter is about 12000 miles and tune up has about 5000. definitely fuel cutting issue tho. please help

Mine is not cutting fuel to my knowledge. It seems to not be firing the coils.

I FIXED IT!!!! I think...

I tore apart the wiring harness between the ICM and cam/crank sensors and separated the ground wire out. There was a burned spot on it where it was folded up in the harness. I taped it up, reintegrated it back into the harness without the fold, and hooked everything back up. I also found a plug wire that wasn't staying connected to the #5 tower. I modified the connector and popped it back on. One or both of those two things fixed it. I've been driving it a lot for the last 3 days with no issues at all!

NICE!

lets hope that did the job

Been beatin' on it all day today with no hiccups or anything. Now I can finally look forward to upgrading the fuel pump!