gsr swapped ek

Car had initial problem of dying out and tach will trip out before it dies. Off the bat I assumed the ICM in the distributor was bad...so I started troubleshooting the coil and ignitor and ended up opting for a brand new distributor.

Now the car runs smoothly but the tachometer would go crazy above 4500 rpm. Even when revved up at idle (not in gear), the tachometer would trip out at around 4500 rpm and above, EVERY TIME.

The tach needle would proceed its way up until it hits about 4500 rpm and then suddenly shoots back down to zero and then comes back up when the accelerator is let off. Yet the motor sounds synch (no miss or stutter), but the tach will just act weird consistently. It will go crazy every single time at around the same rpm.

Any ideas?

 

Nobody? What happened to all of the tech gurus??

 

probably a problem with the distributor you put in. If it didnt do it before, you would think it was the new one. Is it new or used?

 

It's a Brand New distributor. The tach was acting weird before also with a dying engine when warm, so it lead me to believe that both of those common problems were because of a faulty ignitor...now that the car drives normally with the new distributor, I'm starting to think the tach problem may be of a seperate case. But what could it be now?

 

Just tried a known good ecm and same thing

All grounds are good & charging system is good.

Also: In neutral the tach will start to shoot down at approximately 4500 rpm but when driven (in gear), it'll start doing it at around 5400rpm.

Anybody got any ideas?? Electrical Gurus where you at??

 

what tachometer do you have? Factory or Autometer? Maybe try wiring up a aftermarket tachometer to see if it works normally. Check your wiring.
What year is your car? original gauge cluster?

 

You was right the first time. Thanks for helping out!

I was first just too stubborn to believe that a "brand new" distributor would have anything wrong with it, so I wasted many hours troubleshooting just about everything electrical and tachometer related to find out everything else was functioning correctly. So I found a different known good distributor and installed it and the tach worked perfectly concluding that the "brand new" distributor was at fault.

I should've just tried to find and test the car with another distributor from the get go and skipped all of the headache, but I ended up learning a big lesson...brand new parts can be defective straight from the manufacture too.