When you go wide open throttle in the car, and then come to a complete stop, the cars RPM bounces back and fourth between 600 and 700 like it's about to stall out. The car also backfires signifigantly, and a noticible loss in performance occurs, I.E. accelorator pedal feels slugish throught the RPM band. There are no misses or arching in the plug wires, the ignition system is completely fresh and has been redone about 6 months ago, so it's not an ignition issue. There are no codes being thrown so there is nothing to pull, however the engine has a noticable weaker sound om the RPMS. So far, Fuel pressure is perfect, vaccum is perfect, and voltage is perfect, gas consumption could be better, so what might this be?


Any help is appreciated.

 

Maybe a peice of your cat broke off inside it and is clogging your exhaust. juat a thought.Thats if you have cats. just guessin

 

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did you check your air filter?

 

It needs to cleaned that's todays task, but it's not enough to cause all this solely.

 

Have you had the heads off recently? When I did my cam and header install, I could not afford new rockers at the time, so I used the factory ones for a while until I could get the pro-mags, and they would work themselves loose after a couple days of driving. It would pop and backfire and not want to run very well at all, and the symptoms would change as the car got warmer, and the outside temp effected it as well. I know it sounds kinda dumb, but with some of them getting looser, and some tighter, valves would stay open, or not open at all, and all kinds of weird problems would occur. Just a thought!

 

had the same problem with mine was the valves needing some adjusting might wanna check that

 

Check for a broken valve spring. Also check your MAF clean it with some electrical cleaner. Clean your MAP as well. Check TPS voltage, also how old are your O2's?

Just some places to start

 

map? where is that on 95?


The car is running rich. I should be a bit more clear on my back fires... they only occur after high RPM's like around 5800-6200. Thier more frequent when you drive the car before the computer goes into cycle.

Thanks for all the replies I'll probably check my valves this weekend, but they don't seem to be making any out of the ordinary noise.

 

Ok well what springs are you running? cam? Lift? could be floating the valves. Also if you are running stock injectors and the tune is maxing them out you could be seeing the resualt of gas being shot at a closed intake valve.

 

Well I took you guys advise and I redid my valves today. I did hte 1/8 turn on them... car feels peppier ...and the engine is quiter now (still loud but good loud) Only problem is that the Rich condition is still existant. I swapped 02's about 30K miles ago... I left them in when I went to Jethots and I'm wondering if that might of done something to them... Is there any way to check these things? or my AFR?

 

my car ran liek that when one of the injector clips wasn't in all the way, i couldn't tell by looking. i found out by pushing down on all of them and then they started to click in again.

 

Ya are probably floating the valves,the lifters pump up and hold the valves open. After a few minutes it settles down and runs right until the next Bonzi run.
Sound right?