++backfires::continued++

[95ZR1#418]

Hello All......

BRIEF HISTORY(Hx): Previous thread: '95 ~5K miles, backfired on start-up 3 times over the summer(loud/explosive type), Key is always held long enough-ON, May backfire the second you touch the key or well into cranking, May do it a several hours after shut down or after it has sat 2-3 weeks. Also, Hx of slow vac leak which after the last backfire pump turned on for a "Blip" every 3 seconds. Recent tune-up, car performs exceptionally well dispite above.

Found a code 32 had been set before starting any work, must have been an intermitant-never saw it set. As previous discussion here, will wait to see if it resets before digging in.

CURRENT PROGRESS: Plenum pulled, Injectors returned from reconditioning- were in excellent shape, spec's after servicing changed little(they gave me a great dicount because they were all good)- First thought was there was a leaky injector. The coils were all tested, all GOOD. The plug wires tested, all GOOD. I found a leaky Secondary Port Control Solenoid all other vacuum valves/conections/components GOOD, all connections plastic zip tied. Car is still apart.

QUESTION: Any other suggestions as to what I can further check out while the plenum is off?- In regard to the Backfire issue?

I feel the vac. problem is most likely solved, but I have not found anything(injectors)which accounts for the Backfires.....

Thanks again for any comments-

 

[secondchance]

Hi,
I have a 94 which has a EGR sensor like your 95.
My symtom was a little different. Occasionally after full throttle check eng. lt would light up and would set code 32-EGR valve issue.
Finally, last summer, when I started the car, she backfired once and I thought I had blown the MAP sensor vacuum. Upon inspection, vacuum line was o.k. but car ran like crap. Turns out the EGR valve had failed and was jammed shut or jammed open. Anyway, replacing the valve solved the problem.
In your case jammed valve may be freeing itself after the backfire. Might consider removal and cleaning.

 

[95ZR1#418]

Might consider removal and cleaning.

Thanks for the info., I will be removing it to check it out ...