90 ZR1 Stalls after intial start-up in about 3 seconds

[John H.]

Over the last few weeks I've driven my 90 ZR1 a handful of times with zero issue. Parked it in the garage and went to use it yesterday. It fired ran for about three seconds and stalled. Does the same thing each time I try to refire. It has gas, although under a QTR tank. Looked for any obvious large vacuum leaks and didn't see anything.

Any tips? Anyone had an issue like this?

[John D.]

Re: 90 ZR1 Stalls after intial start-up in about 3 seconds

Sounds like the idle air control valve (IAC) to me.

[Douglas L.]

Re: 90 ZR1 Stalls after intial start-up in about 3 seconds

Hmm, are you getting a flashing security light? As I remember, 3 seconds is the amount of time the engine runs before the immobilizer kills it if it doesn't recognize the key on a GM.

[John H.]

Re: 90 ZR1 Stalls after intial start-up in about 3 seconds

Thanks for the responses. No security light flash that I remember, but I can try another key in the events its a VATS issue. I'll check on the IAC. Thank you both.

[Edward J.]

Re: 90 ZR1 Stalls after intial start-up in about 3 seconds

John it sounds like to me the throttle body needs cleaning and then un-hook battery for a minute to erase idle strategy's, sometimes what can happen is-If the battery goes dead it restarts the computer learning process for the idle speed when re-started and when you have a dirty throttle body may have the effects of what your experiencing. The computer over the years has made its adjustments (steps) to the idle air control to compensate for carbon behind the valve. If you have not cleaned the throttle body before let me know I will give the step by step.

[Tyler T.]

Re: 90 ZR1 Stalls after intial start-up in about 3 seconds

Primary fuel pump. When you first start both pumps are on. When engine comes up to temp, the secondary pump stops and primary pump remains on line. If the car dies then primary pump has failed, This failure is quite common on ZR-1s. Pull whole pump harness and replace pump.

Additional information can be found here: http://www.zr1.net/forum/forumdisplay.php?

Just do a search on fuel pumps.

Tyler

[John H.]

Re: 90 ZR1 Stalls after intial start-up in about 3 seconds

Took a while before I had time to dig into this issue. It turned out that vacuum line under the plenum blew off of the mass air flow sensor.