I'm not sure if this issue has been covered. I have a Sidekick 3 so my browsing abilities are limited.
My issue is this; I start up my 1988 IrocZ28 5 speed camaro and it cuts off after it revs up. I can keep it running a little longer if I pump the gas, but it still cuts off.
I replaced the alternator with a refurbished/new one. I also removed the MSD ignition box. After I took the box off that's when I started to have problems. When the box was on, coincedentally, the RPM gauge would bounce around like a horny rabbit.
Can Someone help me out before I have to spend tons of money trying to figure this out with a POS mechanic?
I'm also planning on either putting a LS1 engine in it or rebuilding the 120,000 mile V8 305 it has in it.

 

Was the tach bouncing while it would run smooth?
Take the ignition module out and have it tested or replace it.

 

Actualy it was. It would sound like it was running smooth, but clearly wasn't getting the proper power. Almost like it was miss firing or off a little bit. No one seemed to know what I was talking about. Could that be because of the ignition module too? I'm going to take it out and test it.

 

Might be. I had an intermitent problem before on a motor swap in a S10. would run fine then crap out then run fine. Was real hard to find until I looked at the tach one day and I saw it was bouncing oddly and the truck was running smooth. I replace the module nd it all worked fine.

 

Well i looked for a module and it looks like the exact one I replaced. I will definatley go get it tested again to see if that is why my car won't stay on.
Would there be anyother reason? Like say I had a vaccum leak? I think I do, but would that be a reason the car won't stay on?

Thank you for your help.

 

I had started a car before and the RPM would go up and down. I shut it off and immediatly knew I forgot to hook the vacuum hose from the booster to the intake. Now that is a massive vacuum leak and the car started. But if you do have them fix them.
But when your tach move irratic and the engine is smooth at the same time then that would say there is a problem in the ignition some where. A poor connection, bad wire(s), bad part...

 

hey sorry to jack your thread but in my 73 when i do about 70mph the tach starts to jump from 2500rpm to 3300rpm but the car runs fine when its doing it no misses or lack of power. any ideas

 

If your module checks out fine test the stator in the distributer.

And to the thread jacker you may have a tach filter that could be bad. Follow the wire from the coil. May be mounted on the firewall.