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Fuel Cut, Spark Blowout, Missing, Gap

240 Views 9 Replies 6 Participants Last post by  John M
I am a little confused.

When I was first installing my manual boost controller it boosted way too high and hit major fuel cut (extremely hard engine jerk)

I have since gotten it to just about the right point, it hits 12 - 13 psi in first and about 10psi in all the rest. But sometimes when pulling in 1st gear, I get what I thought was fuel cut. Now I am not so sure. It happens for a split second somewhere around 5,000rpms but then stops and resumes pulling. There isn't any jerk, just a lack of power and a change in engine sound. It then goes right back to normal. And this is happening around 13 psi, so I am lead to believe that it is not fuel cut becuase that should only happen above 14psi.

I am wondering if it could have anything to do with my spark plugs. I have 46,000 miles on these plugs and they were gapped to stock specs. I am wondering if this could be the cause to this strange feeling. Is it something like missing? or spark blowout? (what do those terms mean anyways?)

Thanks for your help, I would really like to run 14psi!!!

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I just installed a Blitz DSBC and had the same thing happen to me. John Adams told me to change the spark plug gap to .30 so I wouldn't get spark plug blowout.
Fuel cut is not a soft, "was that fuel cut" type of event. It is a sudden "what the hell did I hit" or "did my engine fall out" kind of feeling. It's like hitting a brick wall.

And yes, your gap is WAY too big for higher than stock boost. Go with .030 and you'll be fine.
So, the higher the boost the lower the gap?
I just did my plugs, & coils, tookt he car down the road at 7psi. No blow out, but i got alot of backfire.

What couses backfire?
I'm thinking my ECU has something to do with it but not sure. It seems to be modded & i think it's allwing a bit more fuel?
It may also be because i was running so low of boost, I may had been to rich.

After i get my Y-pipe in I'll up the boost & maybe i'll find out something.
The Accel setup is supposed to handle increased boost and still keep a largish gap - most run .035 to .040 with no problems up to 20psi. After a datalogger, the coils are my next mod. If I hadn't jumped on a set of the OZ Tubolare's 17x9 for $320 delivered, I'd be closer to that goal :)

Have you done anything on the fuel pump side? At least do the relay bypass to make sure you've got 100% fuel available. 8v at WOT sucks!
John M. I havn't done anythi9ng w/ the fuel pump yet. I was planning on doing the bypass but i don't know if i trust myself.
I gaped my plugs at .037
Sabotage said:
No blow out, but i got alot of backfire. What couses backfire?
Did you get the throttle cable set too tight?
Jeff Lucius said:
Did you get the throttle cable set too tight?
I don't think so, I marked it when i took it off, & set it back to it's original place.
I think I suffer from this, but I didn't before. It just started fairly recently under WOT. I have a manual controller set to 14.5, know it ain't fuel cut, I've been there before.

I am planning on new plugs/wires this winter. Need the procedure on this bypass too.
I have the text how-to in every sig. M Pro also has the procedure documented with pics - his link is in his sig as well.

I guess while I'm at it, I can also plug my patented "check your TPS" response. You'd be surprised how many cars have probles with these two things. (not inline to reduce bandwidth)
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