Choking for air?

[RedogOnyx]

Hey all,

I posted a few days ago about the 3x ref high wire, but I read something on the net about a guy that had a rag in his stock air box and it would cause the car to miss and stumble above 2000 RPMs cause the car couldn't get enough air

Now I currently have a stock upper on a stage 2 lower and I just trying to find the time to put the upper on (moving and divocring and all)

Car has new plugs (only 5 I couldn't budge #2 and I'm going to the shop cause if I break it off I'm SOL) new ICM and new coils. Wires are about 6 to 8 months old.

I'm also going to have him check the fuel pressure.

The car misses less since the new plugs (Stock ACDelcos v ACDElco rapid fires #14) but #2 still has the Rapid fire in it. After it's done missing, it will pop out the exhasut

[RedogOnyx]

ANybody?!?!?!?

[pocket-rocket]

You only posted this an hour and a half ago. Most people probably only browse the board once a day. Have you run the car in the dark to look for wires arcing? I know you said they are new, but that doesn't completely rule them out if they got chaffed/pinched. How is your timing chain? Fuel pressure wouldn't be a bad thing to check either.

[RedogOnyx]

No Arching.

I was running the car last night around midnight before I left work

[pocket-rocket]

Does the exhaust sound any different besides the miss? Just wondering if your exhaust is starting to plug up.

[60dgrzbelow0]

If the "popping" event presents itself when the car is at idle... take a 3" X 6" strip of printer paper and drape it across the end of the tail pipe(s)... it should lightly flutter like a Hummingbird in a hover against the end of the pipe... but....if the paper suddenly gets sucked back up inside the pipe... then one or more of the engine head valves is losing its compression seal ...and a Valve Job is indicated. If you have true dual exhaust, you can narrow down which bank is involved... but the definitive test involves both Dry and Wet Compression testing... and since "In for Penny...In for a Pound (ing)..." applies here...it makes better sense to pull and do both heads and have a "Balance of Power" in the engine afterward.

[RedogOnyx]

I hooked my scanner up to it today although there was no SES light and I got "P0336" which is CPS range or performance problem

Which one is it? the 7x or the 24x? (I would think the 24, but I'm just taking a stab) and I read there is a relearn involved, how do you do that?

[RedogOnyx]

If the "popping" event presents itself when the car is at idle... take a 3" X 6" strip of printer paper and drape it across the end of the tail pipe(s)... it should lightly flutter like a Hummingbird in a hover against the end of the pipe... but....if the paper suddenly gets sucked back up inside the pipe... then one or more of the engine head valves is losing its compression seal ...and a Valve Job is indicated. If you have true dual exhaust, you can narrow down which bank is involved... but the definitive test involves both Dry and Wet Compression testing... and since "In for Penny...In for a Pound (ing)..." applies here...it makes better sense to pull and do both heads and have a "Balance of Power" in the engine afterward.

No not at idle, only at 2000+ RPMs after it stumbles and misses

[RedogOnyx]

Does the exhaust sound any different besides the miss? Just wondering if your exhaust is starting to plug up.

Not really, except for the popping with the missing.

I want to get it fixed because I know the car's dumping fuel into the exhaust and that WILL plug the cat and this cat is only a year old. (old one rusted though)

[Tbay99Venture]

You might be able to run with the 24x connector unplugged just to compare the behavior, but you'll need to have the engine already warmed up before the PCM will go into closed-loop mode and attempt to use it. As for the 7x, have you checked the condition of the terminals? The ICM was replaced but maybe the older female connections aren't seating down on the pins, or are corroded. Is the twisted wire pair rubbing against the trans, exhaust heat shield or something else and wearing through the insulation?

[86FieroSEv6]

"there is a relearn involved" . . . are you referring to cam/crank correlation factor? I believe you need a bidirectional scanner to initiate this process.

[Superdave]

I'd throw in a new 7x sensor and see if that helps (that is the one in the back of the block just above the oil pan). I've seen that one do some strange things.