Thread: backfire after injector install

Hey guys, I installed some evo 560's on my gtir motor and now i'm getting alot of popping and backfiring at 0% throttle. I am compensating for them with e-manage, which works perfectly until you let of the gas. I noticed some of the plastic tips of the injectors had small cracks in them. Could that be it? If not let me know what you think! Thanks

I could be wrong, but deceleration enrichment is pulse width controlled. Now you're dumping about 50% more fuel upon deceleration which would lead to the back firing. I don't think e-manage can do anything about this?

This doesn't happen at idle and 0% throttle, just letting off, correct?

Correct, it only happens at 0% throttle on deceleration. It's very annoying.

Time for real fuel control.

So you're saying there is no way to fix this without a true stand alone? That sucks, I wish someone would have told me this before i bought the thing. I assume everyone on here using the emanage has this same issue then but they either don't care about it or never talked about it on the forums.

I was under the impression that the ecu completely cut fuel on deceleration. Can you explain pulse width?

Did you make sure to replace the injector O rings and then pressure test the fuel rail to make sure it is not leaking?

My car was backfiring after I installed new injectors and failed to pressurize the fuel rail and check for leaks.

I never pressure tested the rail, how do you do that? It's not leaking outside the rail at all. I just found it weird that the car drove completely normal except for deceleration. There is no miss fire at idle or any other time, just decel.

no the injectors do not cut off during decel. Pulse width is the amount of time the injector stays open measured in m/s. Even a safcII has a decel fuel adjustment and you can adjust for different throttle postions. I just think the emanage is not tuned right.

It must be newer cars that cut the injectors on deceleration then. I've tried taking as much fuel out of the map as possible at 0% throttle at different rpm points. It never changed anything. I wanted to sort this out before i get it tuned professionally, so it's defenietly not tuned "right".