Engine surging and dieing

[holorinhal]

99 grand prix gt. 3800, engine surges and tac pulsates +/- a couple hundred rpms. Some times it will do it while setting idle and sometimes it will surge while under acceleration. some times when stopped at a red light it will surge and die. It will restart and if you keep a little throttle it will stay running. If it sits for a while, it will start fine and run fine untill the next episode, which may be a while.

I was having the crank position sensor symptoms, and have changed the sensor a few weeks ago for the second time in four years. after the sensor change it ran fine untill a couple days ago, when it started this problem. There are no check engine lights or stored codes. Any sugestions would be greatly appreciated.

[nos4blood70]

It's weird that the tach is still doing that. Hmm. Test your ICM and coils. MAF too.

[Ricky21]

Sounds like a crank position sensor again but thats really odd that it started back so soon. maybe ignition coils or vac leak?

[holorinhal]

Ok so after not really trusting what my wife was explaining about the problem with the car, I drove the car for about 20 miles, with street driving and interstate driving and it ran fine, with no isues.
A couple of days later we took the car out for dinner. Just driving down the street, a couple blocks, under normal accelleration, i could feel the car surging a little, and the tac bouncing a couple hundred rpm. Got on the interstate and accelerated to speed, about 65 mph cruising and when you accelerate a litle to around 2500 rpm the car would start surging and tac bouncing a couple hundred rpm. If you let off to under 2500 the ca would quit surging.
After dinner, just driving down the street at about 35-40, the car just died, but fired right back up. There was no engine light displayed.
Now my wife claims that even driving down the interstate, some times the car will just die, but will start right back up.
Yesterday She was driving and it and it died while moving, and the check engine light finnaly came on. When I checked it there were 4 codes in the system, P0171, PO327, P0336 and P0716. Now I am not sure if the crank position sensor code was allready in there, becouse there were no engine light on, when i changed the cps and I did not check for stored codes. The CPS is only a couple of weeks old. and what the car is doing now is not the same as before the CPS change. Any Ideas?.....

[gpse2000]

maybe a maf?? just a guess not sure what all the codes are. but my 2000 would run rough then die but yet start back up with no check engine light on.. ended up being the maf.... that surging can get dangerous i was at a stop light and it surged and i didnt have my foot on the brake that hard and i almost rear ended the car in front of me lol

also would run fine somedays and run like s*** the next with the bad maf

[holorinhal]

Ok so I cleaned the MAF sensor with some electronic cleaner. It really dint look dirty, but did it any way. I checked for vac leaks and did not find any. Any other ideas?

[nos4blood70]

Swap your ICM and coils with known good ones.

[holorinhal]

Yea I dont have any known good extra ICM or coils. I would have to purchase new ones. I know that we are saying that a p0171 is a vac leak, but i have yet to find one, but I will keep looking.
Any ideas about the other codes?

[Brandonkent]

i had similar issues with my car surging and dying and it turned out to be there fuel pressure regulator.

[mikedinthecity]

i was thinking fuel but i am more leaning towards the ign control module. i would def try to find a good used one to try as these can be expensive and based on a guess i wouldnt run out and buy new... cars sure can be stubborn. hope you figure it out.

[sevenhellz]

not sure if this will help but my 2001 grand prix did this and it ended up being the spark plug wires. but mine was a little more excessive then just a few hundred rpms. so i switch out all my coil packs and all new plugs and all new wires and the problem was fixed. i would be accelerating and out of no where it would basically die out but never to the point of full stall. it would always stay running just acted stupid. they told me it was probably a short somewhere in the spark wires, cut wire or something but never found.

[Z34Phoenix]

find someone in your area with a scan tool or tuner and make sure your map is not showing a vac leak, your maf is correct and all before just throwing parts at it.

[Paintball0027]

I'm kind of having the same issues. I had these issues two years ago and ended up replacing the MAP, and it didn't help. Replaced the MAF and that was it. Ran fine for two years. Two weeks ago it randomly stalled while driving. I could keep it running by giving it gas. Unplugged the MAF to test it, stalled immedietly. So I think the MAF is fine. Changed the PCV valve kit and it ran fine for a week with no problems. Now it starts to studder randomly with the RPM's just bouncing around from 1k to 1500. Sometimes while driving and giving it gas the engine studders heavily. When I press the gas I can hear my cold air intake stop and the RPMs drop. Once I let off the gas I can hear the intake start back up and the car tries to run.