EK9MAX

Having some bucking problems that just started after installing a fuel pump.

I'm gonna swap the plugs out tomorrow with some fresh ngk bkr8eix.

I'm running around 10-13 psi.

What gap should I be running? The set I'm taking out are factory gap at 0.32 I beleive.

Thanks!

APoner

Threw them in at stock gap. 16 psi and no ignition break up.

If you put in a pump and the problem started after that i would check there first.

EK9MAX

My injector duty cycle looks good.

My tuner (evans) looked at the logs and think it's either fouled plugs, or the gap is too big.

Here is a pic of my plugs that I just took out. I tried to squeeze a 0.30 plug tool in there and it wouldn't go. I would guess it to be around 0.27-0.28......

APoner

Did you hard wire the pump? If you didnt, i would. Stock wires are barely good for 12 amps. Most after market pumps are happy at 15amps I say amps because when you have a higher load (the new pump) on the stock wires the pump wont see 15 amps under heavy load. You will get the same symptoms you are describing.

If you did hard wire the pump i would check grounds and relay connections. See if the relay you installed is unusually warm or making a buzzing sound

EK9MAX

Ya I wired it in with the sos 12gauge wiring kit.

I'll swap plugs and if that doesn't fix it I'll check the relay and grounds

EK9MAX

Do my plugs look ok?

s2000Junky

yes the plugs look good/typical. Your gap of 0.30-0.28 should be right on the mark for your boost amount/400ish whp.

EK9MAX

Great. Well I'm gonna drop some new plugs in there anyways to eliminate that possibility.

CoolGuy094

X2 on this. I have no problems at 16 PSI with the stock gap on those NGK's.

camuman

mine are gapped down. if you are getting break up i would eliminate gap as a potential problem. i cant remember the exact number, but mine are gapped way down. like around 22. i was having some break up issues and this eliminated it all. its weird though you didnt have the issues until you swapped the pump. have you logged the runs where it breaks up?