I installed My Whipple about 6 mos ago. I had no problems until I installed my headers and exhaust. I have no cats and straight through Magnaflows. The rear O2 sensors have been shut off. I have a problem when in first gear and the tires are spinning. The motor feels like the spark is being blown out. I bought new plugs and the high output COPs. They didnt fix the problem. I can now only assume that the problem is with the fuel. Any help would be great. I had the truck checked on the dyno but it would not fault on the dyno. On the street it will happen every time in first gear while spinning.

 

What gap do you have the plugs at? If the spark is being blown out, they need smaller gaps. What a/f is it running at wot? If its too rich, the plugs can fail to fire also.
On the dyno, if you can get the dyno operator to run the test in a lower gear, so the engine accelerates more quickly, you should be able to re-create the problem. If you can't do that, can you do a data log on the truck while you create the problem, so you can see what's happening?

 

A/F is 11.7-11.9 at WOT. My plugs are gapped at .32. The only time that this happens is when the tires are spinning at high RPMs. I am leaning towards needing bigger injectors and MAF. Does this not sound right?

 

With the tires spinning in first gear, the engine is actually not fully loaded - that's why I suggested getting the dyno guy to do a run in a lower gear to demonstrate what happens when the engine spins up faster. Its possible that the load drops enough that the engine leans out, or that the dynamics of the air intake are different with fast runup and the cylinders see more swirl.

I doubt that more fuel is needed, and I doubt that the maf is the problem. You could confirm this with data logging, as you could see if the maf is pegged or if the injectors are on too high of duty cycle, but I'd be suprized if that's it.

 

Thank you! I will try to have them run the dyno in 1st gear. I'll let you know the outcome.

 

How big are your injectors now? Do you have the factory MAF?

 

Factory MAF and Injectors.

 

Have you datalogged the truck yet? Also, this may sound silly, but have you disconnected the battery, waited 15 or 20 minutes and reconnected it?

 

No chance he is bumping up against the rev limiter is there?

 

This can happen anywhere from 3,000 to 5,000 RPMs. I data logged this happening on my diablosport tuner if anyone can view it from their computer.

 

you should sent it to me

 

Send me your e-mail to abigjj@comcast.net

 

I sent you an e-mail