Spark blowing out... i think....

[SleepinGVR4]

So I've been having problems with the spark blowing out. It only does it at high rpms. Its not fuel cut because I know what that feels like. It just starts popping.

I've replaced the plugs and regapped them to .026-.027, that seemed to help. Tried another coil pack, and tried Hill's COP, didn't help. Plug wires are new.

I also noticed its kinda leaning out up top but I have zero knock. I've seen the wideband as high as 12.5. Part of the problem with it leaning out was the line between the fuel pump and the sending unit had a hole it in. But I fixed that.

Mods...
Built motor
E316G
850cc injectors
supra pump (rewired)
FMIC
EVO 8 mafs
Keydiver chip


Any ideas?

 

What plugs are you running? I've run that turbo and never had any issues with spark blowout. Are you sure it's not a lean misfire? Is it every gear?

 

[ktmrider]

^^ +1, 15-20psi you should run BPR7's, above 20psi run BPR8's.

 

I've never run 8's. I always run the same plug BR7ES non projected. I tried 8's in a customer's street car and they seem to foul quicky on a street car. I really think there is another issue somewhere.

 

Quoting SleepinGVR4:
So I've been having problems with the spark blowing out. It only does it at high rpms. Its not fuel cut because I know what that feels like. It just starts popping.



Are you sure you're not too rich?

 

[SleepinGVR4]

Quoting ktmrider:
^^ +1, 15-20psi you should run BPR7's, above 20psi run BPR8's.



Where did you get that info? I'm running BR7ES's, there is no need to runs BPR8's. There is a guy in PA putting down 650 WHP running BR7ES's so I know I don't need to run the BPR8's.

Quoting Keydiver:
Are you sure you're not too rich?



Not according to the wideband. Jeff, I don't have the dual image mod hooked up, would that have something to do with it? The wire is just secured under the dash because I wasn't sure how to hook it up. But now that I know I just need to ground it. I'll hook it up.

 

[ktmrider]

^^ Geesh, tons of posts on plug usage and boost levels. Run what you want but I can tell you that the plug heat range can do precisely what you are describing. Don't rely on "someone else putting 650whp", unless you mirror his setup exactly.
Poor/bad gas, high IAT's, fuel pressure drop or instability, list goes on.

 

Hate to say this, but consider replacing your wires when you have spark problems. Other peoples comments might be more to the problem, but "knowing the wires are good" is meaningless.

I had a car, bought new wires, plugs, distributor, after a motor rebuild. Fired it up, dead on one cylinder. We spent 2 days chasing fuel injectors, ignition timing and valve problems that didn't exist before I swapped the "know good brand new" wire on the dead cylinder for one of the ones we had replaced.
Problem went away instantly.

The bad wire even passed the (in my opinion useless) screwdriver test, ie grounding it to the valve cover.

 

[4thStroke]

Funny this came up. I was just at English talking to Aaron about this. I was getting a quick stutter at 35 to 37 psi from the Evo3 16G. Aaron just I just need to gap them down to .020. They are the 7s with E85. It only does it when Im cruising, drop down a gear or two and go. From a dig and rowing through the gears, they arent blowing out.

But at 20psi (assumption), your problems may be elsewhere.

 

[SleepinGVR4]

Quoting 687OF2000:
Hate to say this, but consider replacing your wires when you have spark problems. Other peoples comments might be more to the problem, but "knowing the wires are good" is meaningless.



I have brand new NGK wires. Plus I mentioned in my first post that I swapped a coil on plug setup on my car and it didn't fix the problem.

 

[SleepinGVR4]

Quoting 4thStroke:
But at 20psi (assumption), your problems may be elsewhere.



I had it set at 24 psi

 

[4thStroke]

Gotcha. Mine were fine until I got the car to hold more boost, and only then did the spark blow out.

Try gapping them down to .020 and see how it runs. You shouldnt need to do that, but if it holds you over until you find the correct solution it might be worth it.

 

[turbowop]

I had issues when I first started using methanol injection. I was using BPR7es but changed to the non-projected BR7es and haven't had an issue since. This is at 30psi.

 

[ktmrider]

What kind of fuel are you running and/or any alky/meth/water? Also which FMIC do you have?
Just a thought, 24psi on a E316g is really close to the max efficiency range. High EGT's or IAT's w/o high octane fuel could be causing hot spots in the combustion chamber. Your O2 may not pick it up either, but could explain the leaning out at WOT and heavy load.

 

[SleepinGVR4]

Quoting turbowop:
I had issues when I first started using methanol injection. I was using BPR7es but changed to the non-projected BR7es and haven't had an issue since. This is at 30psi.



Whats the part number for those plugs?

I always put 93 in my car. Yesterday I even put race gas in it to see if I could figure out which fuel map my ecu was using. It still did it.

I have custom ETS intercooler, so i'm sure thats not that problem.

 

[ktmrider]

^^ That's good on the race gas, how much did you put in and how much 93 was left in the tank?
Make sure you note that Whop is running methanol with those plugs and 30psi. Not to keep harping on it but those high cylinder pressures, warmer ambient air temps, and no race/E85/meth is what I am "leaning" towards as your issue.
Pun intended on Leaning BTW...

 

[1941Galant]

Since he is at work, I'll answer for him. He had about a 1/4 tank of 93 left, and then dumped 4 gallons of sunoco blue (112 octane) in. It wasn't cutting out as bad, but we also installed my COP at the same time, which works fine on my car at 30 psi. His A/F ratio was around 12.3 w/ the race gas in the tank, and it was cutting out around 6k rpms. He was also not seeing any knock.

 

[BoostedAWD91]

last night we went out and tested it in the nice cool air and it would pop over 6k at 23 psi and wideband was at 12.5. it pulls hard all the way up to 6k and shifting before it hits 6k it pulls all the way strong . it seems to only be a problem over 6k

 

[SleepinGVR4]

Quoting ktmrider:
^^ That's good on the race gas, how much did you put in and how much 93 was left in the tank?
Make sure you note that Whop is running methanol with those plugs and 30psi. Not to keep harping on it but those high cylinder pressures, warmer ambient air temps, and no race/E85/meth is what I am "leaning" towards as your issue.
Pun intended on Leaning BTW...



It doesn't matter what the ambient air temp is, it still pops. My injector duty on pump gas at 6K rpms isn't even at 50%.

This is driving my crazy.

 

[SleepinGVR4]

Come on someone mention something I haven't tried already.