new owner troubleshooting

[YoungGun]

well i bought a grand national today and no more than a block from the dealership it started acting up. the engine would run at normal RPM for a few seconds and then the surge to a higher RPM for a few seconds, then drop back down for a few seconds, and so on. then the car started jerking occasionally, sometimes violent enough to bark the tires. well a drove it to a gas station and observed that the RPM surge was preceded by a click under the hood, as if something was clicking into work, and would occur at idle, in neutral, and in drive at any speed. when i went to back it out the the parking spot it died and refused to start. after sitting there 30 minutes it started right up and after letting it warm up I drove it around and it ran as perfectly as on my test drive with no surging or jerking. after shutting it off it again refused to start. 30 min later i started it up just fine and drove it home with no problem other than a little less violent jerking when i got on it on a straight stretch. it seems that the not starting part is a problem in the fuel system, but i dont know if its related to the RPM surging and the jerking while going down the road. im takin it back the dealership tomorrow to get it looked at, but any input or advice as to what my problems might be would be greatly appreciated.

 

[Blown&Injected]

If you bought it from a dealer, you should take it back.

You will need a scan tool if you will be working on the car your self and that is the tool that will help you find problems.

Could be a loose or failing crank sensor or maybe cam sensor. The ingition module and or coil pack may be failing.

Lots of good info here:
http://www.gnttype.org/

 

[LV GN]

i would check the fuel pressure while cranking it over . there is a place to hook up a gauge on the fuel rail . just in front of the fuel regulator. should be in the 30 lbs. range

 

[Shane]

I'm thinking fuel pump relay for the no start problem. Take it to the dealership for sure. I don't know about the RPM troubles, my only question is was the engine speeding up audibly or did you just look at the Tach?

The stock tach/boost gauge is a piece of crap.

Welcome to the wonderful world of GN's. Word to the wise; ask around on here to find a good TR mechanic locally, or prepare to become one yourself. You can't really take these cars to just any mechanic, especially if it's been modified.

 

[YoungGun]

problem solved

i took it back to the dealership and they replaced the ignition module, which was toasted. she runs like a champ now. thanks for the advice guys.