random miss fire at 3,000 rpm??????

[Logue]

check engine light comes on and the car starts to shutter at 3,000 rpm and above. the computer diagnostic says it is a random engine miss fire. the engine was just rebuilt with 300 miles on it and it has a 1g manifold, throttle body, and head. i just bought the car and have no idea what it is. i'm going to try new plugs and wires. but i think it might be some kind of manifold vacumm leak or something any thoughts ould be appreciated. driving over 60mph is almost impossible

Thanks JJ

 

[AwdEi]

My car has done this before. I would just check to make sure every harness has a good connection.

I have no idea why mine did it, it only happened when staying at 3500 for a while on the interstate, but has never done it again.

I dont see a vacuum leak being the problem.

 

[boostle]

This is pretty strange, your car has the exact Random Misfire/Limp-mode problem that occurs when you swap a 1G motor into a 2G. For us 1gina2g folks it's because we no longer have a crank position sensor, but you should still have one...unless someone put an entire 1g motor in there. Check the connections to you cam angle sensor and crank angle sensor.

 

[Logue]

well today my friend help me on the boost leak we hooked up his boost leak tester and found air is coming out of the throttle body seals. but not enough to make the car studder. i have the i guess its the cam angle sensor on the right side of the motor but the plug is just hanging there is nothing to plug it into. more info on the cam angle sensor would be good. becuease this is what i think is causing the problem.

 

[boostle]

edit: got your PM dude. Basically whoever sold you the car had no idea what they are doing. You'll need to read through the 1Gina2G Tech article on http://www.magnusmotorsports.com and RRE.

http://www.magnusmotorsports.com/1g2g.htm

and

http://www.roadraceengineering.com/1g2gheadswaptechtip.htm

 

[boostle]

You should join this group also:
http://autos.groups.yahoo.com/group/DSM1gina2g/

 

[Logue]

i did yesterday