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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have a 97 Z24 cavalier that runs fine until you drive over

Customer Question

I have a 97 Z24 cavalier that runs fine until you drive over half an hour, when it bucks and sputters and backfires. If I leave it to cool off for a couple hours, its good to go again
Submitted: 1 year ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 1 year ago.

Hi, My name is ***** ***** for the delay.

I will do my best to assist you.

does the engine light stay on?if so,can you give me the computer codes?

Customer: replied 1 year ago.
The engine light cleared, but does come on when it fails. It's like the timing goes instantly out of whack, and the code is for the crank sensor
Customer: replied 1 year ago.
Also on the scanner (before it cleared):
Evaporative sys NOT READY
oxygen sensor NOT READY
P0335 was on 2 scanners, P0157 was on one of those
Customer: replied 1 year ago.
Ok, I just started it to double check; 10 minutes of idling nicely before it started to sputter & surge. These are what the scanner said: Crankshaft position sensor A circuit malfunction
Camshaft position sensor A circuit range/ performance B1I/M Monitors
Catalyst NOT READY
Evaporative sys NOT READY
Oxygen sensor NOT READY
Customer: replied 1 year ago.
The codes cleared, it started again & is currently idling.
Customer: replied 1 year ago.
8 minutes later, it quit & all results the same as the first, except now there's Htd 02 Sensor NOT READY as well
Customer: replied 1 year ago.
The codes cleared, it started right up
Customer: replied 1 year ago.
now its been idling fine for an hour. I'm going for a test drive
Customer: replied 1 year ago.
an hour idling, a 42 km test drive and 1 speeding ticket before it crapped out on me.
Expert:  Tim's Auto Repair replied 1 year ago.

ok.from the way you explain,,this still sounds as if you may have a bad crank may want to try another,,these can do this with heat sometimes when they are bad,,just because it is new doesnt mean it is good

lets try another

than ks