Trying to track down the stumble on the right side of my engine. There seems to be some kind of miss on the right side of my engine. It has a bad stumble/hesitation and wants to stall at take off. The Idle drops down to 500rpms at idle everytime I stop then eventually pulls it up to around 1000rpms. I can kind of hear something in the pass side header, im guessing its excess gas hitting the header. Its not a pop but almost like a steam heater type of noise. The problem has been going on for a couple of weeks now. Last week I found out I had a pretty bad exhaust leak on the pass side due to bolts coming out of the header. I changed the spark plugs and repaired that last weekend and now it got worse doing what it is doing now. I'm getting horrible gas mileage and a real lack of power. I checked the bolts and plugs today and there is no carbon marks on the plugs like last time from an exhaust leak after 100 miles of driving after the fix. I checked the plug wires as best as I could with a visual inspection and they look fine, no burns nothing. Checked them in the dark and didn't see any arching. I may take them off and route new ones over the cover to just rule that out completely and be able to guarentee they can't burn.

I also re-adjusted all the rockers when I did the plugs to. I changed the coil and opti a couple weeks back due to a different problem so I don't think thats the case. I also noticed the vent tube coming off the pass side valve cover had oil on it and I took it off and the throttle body, where the vent tub e hooks up, had oil in it. Is that normal?

 

Went for a drive tonight, waited for it to warm up then took it for a WOT run in 2nd gear and a couple stop and goes afterwards. I logged it via freescan and uploaded it. I also logged some diagnostics, which I have no idea what it is but I'll upload that to. The idle wasn't as choppy this time and didn't really drop to much.

http://www.mediafire.com/?zm222um2miz

http://www.mediafire.com/?ntdyrnquqcj

 

Not unusual to find a bit of oil in the vent tube from the passenger side valve cover, and a small accumulation in the top of the throttle body. That is typical of an engine spending a lot of time at high RPM/WOT where there is little manifold vacuum to help the PCV system evacuate the crankcase. If there is a large amount of oil:
-make sure your PCV valve is not plugged
-check for excessive ring blowby
-make sure the valve cover vent baffle is not missing under the vent hose connection grommet.

The only place there is a major imbalance in fuel flow to the right side of the engine is at idle. Its adding about 13% extra fuel to the left side, and 23% extra fuel to the right side. Most of the other cells seem to be within 1 or 2 counts of each other, and not adding a significant amount of fuel (ignore cells 17 and 18 because they are mathematically derived from the other cells). That would indicate that whatever your problem is, its mainly affecting the performance at idle. The cam and how well its tuned for it would be a major factor. The MAP is typicallly 56-59kPa at idle, so it doesn't appear to be a bad tune, valve adjustments, etc.

This could be a case of a small exhaust or vacuum leak affecting primarily the right side of the engine. You mentioned in another post that the exhaust leak was due to a bad heli (not "hemi" ) coil on the #2 header bolt. Did you get that fixed?

Look at records near 542. you are opening the throttle, but all of a sudden the RPM drops from 1075rpm->500rpm, the air flow drops significantly and the system voltage drops from 13.x to 12.1V. The left O2 sensor bottoms out near 0.040V. Is that when it stumbled? It happens similarly at record 886, but not as severely.

 

Ok yea I've just notiuced some oil coming into the manifold.. Haven't really been driving it except for the track. I don't have time or money right now to fix the heli coil, but I was actually able to get the bolt in there with a washer for now and I pulled the plug and checked for carbon marks and it seems that it has fixed the exhaust leak for now.

That is exactly when it stumbles and almost stalls. The throttle breaks up under 2000 rpms and I can even hear in the car, it has more of a raspy sounding exhaust instead of the smooth grumble it had the first week I had the cam in. I can also feel the lack of power compared to that first week. I originally checked the vaccuum lines last week when I did plugs, but ill go over them again. Isn't there a tool I can hook up to make sure it is pulling enough vaccuum? At record 886 I don't think it happened as severe because I didn't come to a complete stop that time. Like I said, yesterday I checked all the new plugs and surrounding area for carbon marks but nothing. And that knock is gone to so from what I can see and hear the exhaust leak is gone. Ill double check tomorrow morning for vaccuum and exhaust leaks..