Any ideas why rpm tach goes nuts, car instantly dies?
 

I bought the car recently..bought a new battery, changed the spark plugs/wires, oil change, new oil filter and drained the fuel. Added new fuel. Car see's 45psi on fuel pressure.. When I was under the car I noticed the cats gone and the metal line that ties into the cats is cut and pinched/crimped at end. The car fires over easy..but rpm hiccups and it dies or it just dies immediately or after running 5 mins.. any help is appreciated.

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

90 iroc z 305 5.0.. tpi.. fires right back up.. but sometimes dies right away immediately.. sometimes tach goes haywire.. stumbles.. then keeps idling or dies

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

I think the tach is operated by the ignition coil, so if the coil goes haywire then maybe the tach would too and the engine would die. Uneducated guess.... I'm no mechanic so don't take my words too seriously.

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Yeah suspect ignition module inside the distributor, or coil. Check the coil with a meter, if it's alright check out the ignition module.

GD

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Ok thanks I'll take a look into it.. i.drove it for the first time today.. and it died and I had to crank it maybe 10 times before it would fire back up..

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Always check for codes first.

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

I replaced the distributor cap and rotor, ignition control module and ignition coil.. car fired right up.. I drove it 2 miles.. died pulling up to a stoplight.. wouldn't start.. just turn over but not fire.. I'm lost.. fuel pump? Timing? Idk about to save up and take it to a shop.. I'm out of ideas/patience

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

any codes?

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

No codes

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Common problem in boats. A bad tack will kill the ignition. Disconnect the tach

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Turned out to be distributor

Re: Any ideas why rpm tach goes nuts, car instantly dies?
 

Yup

bad pickup coil in the dist will cause the tach to bounce as it misfires and fails.