Missing pretty bad under load

Redog · 05-11-2011, 04:46 AM

OK this only started about 3 days ago.

Under load the car misses pretty bad. Tonight it was really really bad. I thought I was going to blow a gasket or a the engine.

Anyway the car brought up a p0101 code, so I replaced the MAF sensor and it seems to be the same or worse

Plugs and wires less than 18 months old and at most 12,000 miles (probably more like 9,000 or 10,000) Fuel filter replaced last June.

Even does this in park revving the engine. Didn't see any grounding or arcing.

Headers are leaking pretty bad on the front 3. Have the gaskets, but haven't replaced them yet. Could this cause this problem?
Could the shift soldnoid do this? I think mine is going. Any other ideas?

[ion] C2 · 05-11-2011, 06:04 AM

unplug the upstream O2s and see if it still happens to rule out exhaust leak causing it

vacuum leak

a.graham52 · 05-11-2011, 07:21 AM

why would shift solenoid in your trans cause a skip in park/nutral and engine revving

highly doubt those are related. agreed with pulling the pre cat o2 to rule out the exhaust. after that get a scantool on it and find out what cylinders are missing and go from there.

Cliff8928 · 05-11-2011, 12:41 PM

Check that there is no source of un metered are getting into the engine. (cracked intake coupler, disconnected breather hose, etc..)

You can check for +12V (Pin C, pink) and ground (Pin B, Black/Wht) at the MAF. The other side of the ground (G102) is at a splice pack near the starter.

Jroc26 · 05-11-2011, 02:19 PM

I'd say you probably have large vacuum leak somewhere and if that's not the case I bet one of the coi packs is going bad. You can try taking the plug wires off 1 by 1 while the car is running and if you pull one off without a change in idle that's your cylinder that's giving you the problem. You could also lay the plug boot near a ground, just use your rad support or something to see if you are getting a weaker spark from 1 or 2 wires.

Redog · 05-11-2011, 06:15 PM

It's weird that it didn't do it at all today

Drove to the post office this afternoon. Normal driving, nothing happened. Drove to work, opened it up 3 times, once to 4000, once to 5000 and got pretty close to 6000 the thris time (don't worry top speed was 50) so IDK

I'll see again tonight

alerored04 · 05-11-2011, 11:09 PM

Unplug the MAF and run it that way. See if it behaves the same. I something similar happen years ago, turned out to be a broken MAF wire going into the plug.

Redog · 05-25-2011, 05:15 PM

Unpluged the MAF and it did the same thing.

My header bolts are backing out, would this cause missing? A guy at work thinks so. I know the car feels like it's losing a little bit of power.

Tightened up the front bolts, that I could get to and drove the car and the same thing happened. Going to try the rear when it cools down a bit. I'm THINKING the rear might be a bit easier just due to the shape of the rear header.

AZFire316 · 05-25-2011, 05:21 PM

The car acts the same with or without the MAF connected? if so then I think something with the MAF is the issue, the car shouldnt run the same with it disconnected as it would with it connected.

a.graham52 · 05-25-2011, 09:23 PM

fix whats not right first. unmetered air could get into the exhaust and the car would think its running lean adn try to run very rich.

jawa · 05-25-2011, 10:38 PM

i had a simular issue, it turned out to be the ign. modual

Redog · 05-28-2011, 12:30 AM

^^ That's only 2 years old on my car

UPDATE: I swapped my stock MAF back in. It still misses but not as bad, but runs like a dog. Seems so much slower compared to it with the LS1 MAF.

Found a HUGE exhaust leak at #2 header. I could hear it better with the stock MAF on. I mean it's really loud. I didn't hear anything from the rear headers, but I found that the rear header looks like it has studs and a stock metal gasket.

So I guess I'm going to swap those gaskets in the front and I'm going to try to remove the header so I can paint it with VFT Flameproof black