Intermittent engine cutout - Fuel System?

[vengebear]

I have a 2000 Grand Prix GTP. This is a weird problem. It has been happening for about 2 months. I will start from the beginning.
- About 2 months ago, the engine would sporadically cut out when I was accelerating. It would always happen above 3000 rpms. I would accelerate and sometimes (1 out of 4 or 5 times) the engine rpms would just cut out, go down to idle and then spring back up again to 3000 rpms. This happened when my foot was on the accelerator and I would not take my foot off. The acclerator pedal would be in the same spot the whole time.
- I have taken it in twice to repair technicians and they couldn't replicate the problem so they said they couldn't fix what they didn't know was wrong.
- Two months later, the problem is still happening. The problem has changed slightly. Now sometimes, instead of shooting back up to where the rpms were initially at, it just dies. This happens when I am on the main road going like 30 or 40 mphs. Again, it always happens approximatly above 3000 rpms.
- Two days ago, the engine did the problem like normal, and I kept my foot on the accelerate while the rpms were down and I blew the fuel pump fuse. I replaced the fuse and it happened again about 4 miles down the road.
- Because it blew the fuel pump fuse, I replaced the fuel pump relay and the fuel pump speed control relay. Since then, the original problem still happens but I haven't blown the fuel pump fuse since the relays were replaced.
- The engine still cuts out (not all the time though). SInce this problem happened and it blew the fuse, I am thining it is a fuel system problem.
- Now, heres what has been recently replaced on my car. I have recently cleaned the fuel system, replaced fuel filter, replaced the two relays described above, and I currently have the fuel pump resistor on order and should be here any day.
- Please, any help with this problem would be much appreciated. Thanks

[ericvrose]

It could be the crank position sensor getting ready to give up. Do a search here on clubgp for CPS. See if the symptoms in those threads (and there are lots of em) match yours.

[vengebear]

If it is the CPS, I have read it is really not a do-it-yourself project. I know the sensors are approximatly in the $30 range. Does anyone know what a average shop will charge to replace the sensor?

[GPme]

If the crank possition sensor is located on or around the harmonic balancer, then the symptoms described are exactly as occured with my car. I had this computer sensor changed and problem was solved. Part was very inexpensive, labor was not bad, BUT a harmonic balancer PULLER is definitely needed. Must get under car to remove, but was very easy to do for my tech. HOPE THIS IS ALL THAT IT IS. Not that big of a deal. Is'nt it wierd when the TACH jumps around like that? When it first happend to me I thought my NITROS kicked in... Oh Yea, I don't have NITROS.
GPme

[BIG-L]

You might try this thread and see if it helps you out.

http://www.automotiveforums.com/vbul...&highlight=cps

or check out some of these other threads about CPS

http://www.automotiveforums.com/vbul...earchid=667627

~Larry~

[vengebear]

Yea, it gets really frustrating when all this happens. I do appreciate everybody helping with this. I am going to take it to my buddy whos a mechanic and have him replace the CPS and check to see if everything else looks okay under there. I will let everybody know what turns out. Thanks Again

[GTPWarrior]

I changed mine on my own and it isn't hard but it does take time and the anchore bolts are 10mm bolts. I had to purchase them seperately.