Car stutters ~6k

[Drifter27_04]

This is for a friend.

He has no way of putting on here so I am.

His mods....

8.5 c/r piston, built head +1mm values, 280 cams, solid lifters, SMIM, 75mm TB. 3" in/ 2.5" IC piping. Large FMIC, tube ex header, 3" GM & MAFT, Precision T & E SC6176 T3/T4 w/ external w/g (17psi), no FPR, 950 injectors.

If there is anything that is needed to know please ask.

His problem is that he is getting a studder in mid to WOT range. we have change the wires, plugs, coils, transister thinking that it maybe in the ignition but still no success. He can pull the plugs and they still look as if he put them in new or they are black as black can be (I assume this is b/c of running no FPR).

 

[boosted86]

try a smaller gap.

 

[Drifter27_04]

I think believe he has the plugs gapped at 25 now

 

[LandoAWD]

What plugs?

What pump?

 

[Drifter27_04]

255 Pump & NGK BPR7ES Plugs

 

[Boosted98gsx]

First off, get an AFPR. 2nd off, either reduce plug gap, or get a boost a spark (ARC-2).

 

[Drifter27_04]

I have been telling him to get a AFPR for every and a day now but he is one to think its not needed


Do you think that this could be a problem. He did say that he gapped the plugs at .018 once already.

 

[Boosted98gsx]

AFPR, set base fuel pressure (different from 1g to 2g, and I don't know what he has), if that doesn't solve it, look at your coils. If you're still breaking up at .020, then the spark is not powerful enough. I wouldn't gap much lower than that.

 

[Drifter27_04]

we have a 1g and I just got off the phone with him and he said that his plugs were gapped at .020 now

 

[Boosted98gsx]

Check the wires, check the coil pack, check everything relative to IGNITION. If the car is tuned to a proper A/F ratio, airflow is probably blowing out the spark. Hell, change the plugs, see if that solves it.

 

[Drifter27_04]

Look over a few longs if possible and see basically what maybe wrong.....we have not dailed in the MAFT yet

 

[redtsi252]

for some reason I dont think its the spark plugs...I have NGK BPR7ES at what ever gap they come with from the box...and Im not having any problems at 15lbs or 25lbs of boost