Alright ever since i switched to my new plugs (1 heat range colder than stock) for nitrous, i have been having severe misfires. but only under certain conditions. if i beat the **** out of it at WOT it runs like a raped ape and as long as it is under load it runs fine and and runs awesome on the spray (To a point, keep reading)

But once i set the Cruise Control or maintain speed anywhere between 50ish and 85ish (2000-3000RPM's) i have a flashing SES light and severe RPM fluctuations. If i get the speed up to 85 it stops, if i keep it under 50ish it stops, if i am on the gas i and i pass 110mph app.4500RPM's the SES light begins to flash.

Also when this happens, my converter refused to lockup causing EXTREME gas consumption

it is driving me insane, below are the steps i have taken to try and remedy the problem:

1. Check All Plug wires (appear externally unmolested)
2. Check connections on all coilpacks
3. Check connections on wiring harness connectors
4. Check Connections on Fuel Injectors
5. Changed Sparkplugs from NGK TR6 to an Autolite Equivalent
6. Stand next to the truck with lit match and a gallon of gas screaming obscenities at the truck scaring my neighbors and at the same time threatening my truck that i'll burn it to the ******* tires if it doesnt start cooperating
7. Explain to police officer that i wasn't going to commit arson
8. Refill gas tank after burning half a tank testing
9. have a jack and coke
10. went to autozone and bought new set of plug wires
11. new plug wires have no result
12. remove coil packs from my truck
13. remove coil packs from my fathers 02 yukon
14. realize we have different connections and i wasted an hour
15. Have another Jack and Coke

and now i sit here, with a still misfiring truck, and a half bottle of jack with my name on it,

HELP ME

This all started after i recieve a 10lb bottle from MTI with a significant about of air in my bottle, upon the nitrous hit i heard a pop and then a squeal and then it went away and hasn't come back

oh yeah, HELP

 

Do you have a wideband? Is it a random misfire (P0400 i think) or is it always a certain cylinder? Do you have logging software? If possible, log your afr and then try to get it to do it again. If no fuel then it will go a bit leaner on that bank. if no spark then I think it will go richer (unburnt fuel will read as being richer right?).

 

bad gas, bad coil pack or bad motor would be my guess. clean the MAF and make sure you dont have any leaks in your intake after the maf....mostly around your nitrous nozzle. what did you gap your plugs to?

it serously took you an hour to pull coil packs? thats a 5 minute job topps haha.

 

welcome to my world, I have been tracking this gremlin for about 2 weeks now. I am running a plug that is 2 heatranges colder and mine is missfireing at the exact same time as yours. I am also throwing an 02 sensor code aswell. Bank 1. I am going to try and change that and see if that helps. I am going to try and go back to warmer plugs and see if that solves it as well. If you get any closer let me know because I am about to go nuts aswell.

Oh and I was told that the higher stall could be causing the problem.

 

did you flip around your MAF sensor plug ?
he probably thought/talked about it for 45 min before that. . . .

 

Seems to be a common problem around here huh?

 

What plug gap are you using?

 

It is a random misfire and my AFR on the spray was accurate as of tuning time but no i dont log it


gas is good, Shell V-Power

I'll clean the MAF when i get home, and i'll check my intake as well.

and i was tired

I'll keep you updated

.035 i think

 

I have a similar problem, happens at part throttle at around 2000-2200 rpms. Code clears on o-it's own after a day.

 

I would try opening the gap up some for when you aren't running the nitrous.