First of all, I have alot of mods, probably all but turbo kit. look under my threads, the mods are under "all vishnu owners, check out photos..."
I have the occasional Burp/hesitation/ missing a step at WOT, usually when someone messes with me and wants to "get it on". the mis-step burp happens for a milisecond, and sometimes it happens in succession when you keep the foot into it. At or near WOT. I have been messing with the boost tables, and have been running consistent 25 psi of boost without taper. I first thought the spark was being blown-out, as I read in a previous thread. once I got the boost down to the sweet spot, which IS 20-22 psi, the problem stopped. I "had" to get on it today with a Camaro Z28 SS. the longer I held the gas at WOT, the more it hiccupped! the boost WAS at the sweetspot, 21 PSI, but now what?????

I took the plugs out that where gapped at 26 4 months ago, and looking at the plugs, they LOOKED fine, but the gap was 36!!!!!!!!!!, so in conclusion, the spark MUST have been getting blown-out. that is a long way for a spark to jump without boost getting shoved into it! Less boost, less change for a "blow-out burp", but consistent boost, more likely hood of a burp blow-out.

Conclusion: (do this now!)

1. lower the boost to its sweet-spot 20-22PSI, play with it to find the sweet spot!
2. check the gap on the plugs. I have the colder plugs in there, and I believe you need to change the plugs more frequently. ( Im changing mine every 3 months) If you do what I recommend in these 2 steps, your problem will be RESOLVED once and for all!! well, it solved My problem. And yes, the camaro stayed in my rear view mirror.

 

Has anyone done the steps above and agree with me? someone owes me a beer next-time we meet!! It seems like you have to change the plugs quite frequently! Will someone answer me? did it help your problem?

 

i shall call you a liar if you can hold 25 psi to redline. Was this 25 psi on pump or racegas? Getting spark blown out could be caused by many things. You just found one cause. It could also be a leaky bov aswell.

 

Yes I did find one cause, the 25psi to redline is on race gas 110 leaded!

 

What are your spark plugs gaped too ??

 

originally gapped at 24, after a 3 month time frame I re-checked and the gap "grew" to 36-38! and these were the colder plugs!

 

I am having the same problem too....


Have you tried anything else besides the spark plug gapping? I have checked ignition wires, spark plugs & spark plug gap. Checked all vacuum lines as well.

I recently just installed 720cc GReddy Injectors and a 255 Walbro Fuel Pump, this started happening a few days after the install. Do I need a tune? Or is something screwed?

Im still running stock BOV (holds boost fine @20 psi), Buschur Exhaust and an AEM intake with no tune... lol

I don't know what else to check unless I am running too rich..

 

I'll probably get smacked for this but i ran high boost levels on 9.5:1 compression for a long time. I had the same issues over time. Some say it's due to the consistant heat of the long pulls being to much for the plugs.

I started using the ZEX spark plugs... has 3 prongs coming into the center electrode. They were gapped to 28. After over a year they were the same. Finally i ruined them by cranking up the boost to much 13psi without pulling any timing.

My piont is... the ZEX plugs were definately worth it. A lot of people use them in NOS applications for the same reasons. They are very pricey but my experiences with them were great!

 

Unless you have a larger turbo, you dont need the big injectors, I would re-tune it as you have too much fuel and not enough air to mix with it.,no your not screwed, when all that fuel is in the combustion chamber, there is a Larger "fire" as you stuff MORE fuel in there! my 2c

 

I would have to disagree with you here to some degree. On my Power FC I was hitting 100% duty cycle even with a walbro fuel pump. Now this could be because of the stand alone, but it was on the stock turbo

 

On a standalone you have to run bigger injectors due to less overlap of the injector pulses.

 

This was on the stock injectors...or am I not getting what you mean?

The Power FC L-Jetro (MAF) is basically a plug and play unit out of the box for a stock evo.