rough idel

[pug]

Just installed rebuilt motor was ideling and running great. Now since its getting colder out idels and backfires through throttle body only when i first start up in the morning or sitting more then 8 hrs after it warms up it runs great. Any ideas 1990 2.5 thanks.

[Pete M]

faulty egr?

[pug]

Can a egr valve be cleaned or just replaced. thanks

[Geonovast]

Can be bypassed. :brows:

[pug]

how do you bypass and will it damage the motor. thanks

[Geonovast]

Remove relay. Plug vacuum lines. Remove pipe and plug holes. Motor should be fine, they ditched the EGR in 91 anyway.

[pug]

Ok thanks will do in the morning.

[pug]

I plugged line removed relay plugged holes took out for drive still backfiring through tbi. Any ideas. thanks

[Pete M]

The egr might be stuck partially open. :dunno:

[pug]

Ok thanks. Will this also cause a lose in power.

[Pete M]

can't say for sure as I'm running into the limit of my knowledge on the egr (never had one go bad on me). I know it has caused plenty of grief for guys in regards to warmup and idling.

[pug]

So i filled up with gas last night drove to work today 60 miles round trip used a half tank of gas. Did not have this problem first 800 miles. Normally get around 280 to 300 miles out of a tank. A ny other ideas. thanks

[Pete M]

maybe your fuel injector is faulty and is spewing too much fuel down the tb. Since yours is a TBI, you should be able to pull off the rubber intake hose and see the injector as is works.

[pug]

I pulled of the hose. looks like it is spraying allright. I have to spare injectors can these be cleaned or rebuilt. thanks

[pug]

I did all of the above. Today took my son back to college today. Still backfiring through tbi and $90.00 in gas (30gallons) and only 290 miles sometimes i can give it gas and will run good other times give it gas and bogs down and backfires through tbi. It is getting exspensive to drive anymore. Any other ideas thanks

[Mike Stone]

Mine is doing the same thing, so if you figure it out please email me. Or PM me, Thanks! Just something i tried was coolant temperature sensor on the intake, it took away my bad fuel mileage, but i still have a rough idle.

[pug]

What else would cause bacfire through tbi besides egr and fuel injecter. thanks

[Pete M]

I was getting all sorts of nasty backfires in my 86 (carbed). I eventually tracked down the issue and it turned out to be corrosion in the feed wire where it attached to the coil causing a really weak spark.

 

but not before I blew the muffler apart. :yes:

 

[maddzz1]

Try replacing the O2 sensor?

[pug]

Sometimes it backfires through tbi. Then sometimes it runs like there is nothing wrong for 3 to 4 days. I just changed o2 less then 3 months ago.