KGV

My 91 backfired when I started it today. I started it a few times, but it ran very rough. Eventually it ran better, but the check engine light is now on. It is also not as smooth as before. I read in a previous post about backfiring knocking the houses off under the plenum. Is there an easy way to check this?

Thanks


[Modified by KGV, 5:34 PM 5/25/2003]

A26B

I would recommend you check the hose from the underside of the MAPS to the rear of the plenum first. It has a tendancy to become oily enough to blow off and will cause a rough idle. The sensor is at the rear of the plenum under an aluminum cover about 2" x 4" in size. You can reach both ends of the hose without taking anything loose. Also check the PCV valves (2) hoses just to the drivers side of the MAPS.

Backfires can be eliminated by holding the key in the start position slightly longer than you have been accustomed to with other cars.

Good Luck,
Jerry
Jerry

FASTAZU

Check the MAP sensor line and PCV line under the front of the plenum left side.


[Modified by We Gone, 12:45 PM 5/25/2003]

KGV

Thanks for the input. I found the line that had come off the plenum at the rear of the engine. Now it runs as normal!

92KNGOHIL

Someone in this forum or ZR1.Net discribed that they continue to crank the starter for a second after the beast fires up in order to limit the tendancy to backfire. I tried this and haven't had a backfire since.

Tim

90 Corvette ZR-1

Sounds like a line blew off the MAP. I had this happen to me twice, scared the poopie outa me both times. Just hold the key a tad longer then normal next time.