backfiring...please help
backfiring...please help
i have an 87 tll 96000 miles on it....after 3,000 rpms all you hear is loud popping...i replaced the acv and it didnt make a difference....the weird thing(at least it seems weird) is that my stock boost guage maxes out and it actually passes the line....thats when all the popping begins...i dont think its fuel cut because all i have done to it is a cat-bacl exuast....please help me out!!!!!!!
Originally Posted by Mint87RX7
your guage is showing you boost spikes, check your turbo system before you blow your engine
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i havent checked the wastegate its sounds like it could be it....and i have a cat back exhuast....when i changed it the mechanic said that my main cat is bad.....im trying to get that racing beat dp and presilencer......ill checl on the wastegate tomorrow and ill let yall know.....could it also be the 02 sensor?
Joined: Dec 2003
Posts: 6,598
Likes: 10
From: Temple, Texas (Central)
Originally Posted by SupraBen
What PSI do is fuel cut usually set at? I have an FCD, so I've never actually hit fuel cut. 

i have my money on the waste gate, he doesnt seem to be having idle issues, a common sign of tps issues.
but just incase it is your tps and you dont already know:
to test:
http://rx7turbo.com/tpstest.htm
and to adjust:
http://rx7turbo.com/tpsadjustment.htm
but just incase it is your tps and you dont already know:
to test:
http://rx7turbo.com/tpstest.htm
and to adjust:
http://rx7turbo.com/tpsadjustment.htm
Last edited by vicious525E; Jan 16, 2005 at 12:41 PM.
BOOSTED Vert
Joined: Sep 2002
Posts: 2,307
Likes: 0
From: Miami
the wastegate is easier than checking the tps.... one, make sure the line from the turbo to the actuator is on, second grap the rod push it away from the front of the car. make sure its not excessively hard to move..plus if you dont have a rough idle then you most likely dont have a tps problem..
well right now i have an idle problem but thats because my throttle cable is tooo tight....i removed my throttle body and didnt check that cable...i dont think i have a bad tps....i talked to someone about porting my wastegate today(cause i dont want to mess anything up) but i had no i dea i had to take the turbo off...so now im gonna take it to a performance shop and see if they can do that for me.....i thnk it really is the wastegate though....it makes sense.... so when you hit boost cut you start backfiring?how is that
No....not yet...im still working on it....i replaced the wastegate actuator line and its fine....it moves freely....the tps isnt the problem....I emailed a guy at rotary ressurection and he said it most likely the secondary injectors.One of them may not be coming on..He said check a "resistor pack" under the afm but i have no idea what that looks like...so im just having someone else take a look at it....it may also be the wiring..Did your car sounds like poppin popcorn?
My car had a nice tone to the exhaust, now a week later it sounds like a duck when i get on it...It only back fired once scared the **** out of me thought i broke something!!! but seems to be working ok hasnt back fired again "YET"...



