: Back fire in the induction system



jeffreykeithpike
07-25-04, 03:10 PM
My 96 eldorado was driven in about 3 feet of water two years ago. Right after that the car would miss in traffic but run fine on the road. It would occaisonally backfire in the induction system. I changed coils, no help. compression check was okay. It began using water about a quart a week. Bars leak stopped the water loss. It now misses much more and backfires at a particular manifold pressure range, not at full throttle and not at gentle accelleration. Could this be due to leaking head gaskets? The engine does run hotter than you would expect in traffic.

zonie77
07-25-04, 03:36 PM
Unless you are consistently loosing coolant it is not head gaskets.

Beside the coils what have you done to it?

growe3
07-25-04, 04:59 PM
I'm not sure if this could be part of your problem; did you ever remove the air filter box? The intake channel box below it might be holding water, which could be sucked up when enough throttle (low pressure) is obtained.

Two years would be a long time to hold water in the box, but if it does not drain it might keep accumulating.

-George

jeffreykeithpike
07-25-04, 06:53 PM
It was consistantly losing water until I put Bars stop leak in it. I could not tell where it was leaking. An auto shop told me that #3 was fouled and when the plug was changed in was okay for a while. I just now changed #3 again and it is running okay again. There has never been any steam that I could detect from the exhoust and there is not any water in the oil. Just now when I test drove it there was no backfire. The backfire seems to begin when the plug begins to foul. The plug has no evidence of oil on it, but it is wet as if it had not been firing. It takes a month for it to completely foul out to a dead miss. At first it misses a little and then after time it hits a little until a dead miss occurs, but when I floor it it will begin to fire. At first (last year) I thought I might have a slightly warped valve, but I do not believe that explains the fouling plug. :confused:

zonie77
07-25-04, 10:36 PM
Possibly a leaking injector. You might check the fuel pressure reg first. If that's ok raise up the injectors and turn on the key (don't start) see if you have fuel dripping from any of the injectors. Esp #3.