This is a continuation of a post I had in the forced induction section. I am hoping for some help here. This problem has been ongoing for a month now. I have replaced intake gaskets, plugs (TR6s'), wires (Crane), and am currently running the stock pulley and Magnacharger tune on my Radix and the problem still exists(I haven't tried a custom tune).
Usually ocurring during cold starts, I notice a misfire at idle and the A/F meter is reading downscale lean. When it warms up the mis at idle goes away, it does not mis noticably at any other time. After it warms up it consistently registers more lean on the A/F meter. It usually even stops doing the lean - rich cycle during cruise and just holds @ stoichiometric. If it does cycle, it will do so from lean to stoichiometric and not all the way across the band. It still shows in the yellow but MAY touch in the green @ wot. I have swaped my A/F meter signal wire between both O2 sensors and have received the same result. I would say this occurs 1 out of 10 starts. If it doesn't start doing it when it is started, it won't do it at all, it will run just fine and fuel mixtures will be just fine. I can usually notice a slight decrease in power @ wot when this occurs. I can shut the engine off after running fine and restart 10 min - 2 hrs later and the grimling will be back. This may take 4 days! The problem started with 1500 miles on the truck, about a week after I installed the magnacharger, and it now has 3500 miles. Most of the time when it misses it thows a P0300, random misfire. Fuel pressure reads 63 psi at idle and 58 @ wot.

Any insight would be greatly appreciated.

 

There has got to be a vacume leak someplace. Have you verified that your injectors are all pugged in, and on the correct injector?

 

Verified the injectors are all plugged in when I reinstalled the blower after the intake gasket swap and I don't think it is physically possible to get them plugged up wrong due to the length of wire coming out of the loom, unless you cut the loom of course. I have tripple checked for vacume leaks visibly. I may get a can of ether after it in the morning while it is idling and check for raise in idle speed.

 

Please call me tomorrow. At this point I want to get your supercharger in and looked at. PLEASE be sure to install the factory pulley.....removing it normally voids the warranty.

 

pm me your # and extension.

 

No need for PM, its all over the web

805-642-8833 Ext. 252. If I do not pick up please have me paged.

 

have you logged which cylinder the misfire is on, checked plugs and wires?

the lean thing is something I get immediately after start until everything is up and running as long as afr lines up after 5 minutes of driving I wouldnt worry about it. If your commanding 14.7 cruising around I wouldnt worry. What are you commanding at wot? Have you tuned the engine for part throttle operation, if not that is your problem with the cycling afr? any kr? Need alot more info I think the afr and misfire are 2 different things

 

I don't have any software to log anything and I just have a narrow band A/F meter. When the problem occurs, there won't be a noticable mis at idle if the truck is restarted after 10-30 minutes, but it will be lean and stay lean for as long as I drive it, which is as much as 50 miles(for sure). It typically is only noticably missing (by feel) when it has been shut off for an hour or more. After the problem initially occured I pulled all the plugs and they all looked normal and no signs of abnormal discoloration. A week later I installed new plugs and wires. I have not done any kind of tuning. It has the tune which came with it from magnasun. When I crank it, and it is missing, it will always register lean until it is shut off. If I immediatly restart, the problem is usually still there.
Remember...It cranks and runs fine 85% of the time. I drove it for over 150 miles sunday with no problems with multiple starts and all types of driving conditions. When I cranked it after dinner Sun night(after about an hour), It had a bad shutter and did as I have described above for the next 20 miles until it was shut off. It was not cranked again until mon morning and has performed flawlessly all day.
I really want to get this narrowed down to a Magnasun problem or a Chevrolet problem. I don't want to go to the dealer with something like this without being sure what it is. They will most likely say it is the blower screwing things up and give me a big hassle cause it is still under warranty.
I will be soon installing a cam, headers, and a custom dyno tune. If it is a tuning problem it could be fixed then. I want to get it figured out before then if possible.

Thanks for your help.

 

Update. My truck finally stayed messed up for 3 days straight. Finally I can fix something that is broke right? I took some advice and uploaded the stock program and then reinstalled the Superchips. It was immediately fixed and has been doing perfect for the last 4 days! Maybe the moment of truth has arrived.
If it is as simple as this I think I may just

 

Here it is like I said. I'm saying problem fixed

I reinstalled the 3.25 pulley and it is running like a raped ape

Does anyone have any insight on why this may occur? I'm also wondering if something similar has happened with 1slow01z71's problem. Both of our problems have occured after the battery was dead or unpluged for a few hours or more. He hasn't solved his yet but he hasn't done anything with the tune yet. I just did a reload and Wahlahhh! went from crap to glorious in 20 minutes! Been perfect for a week!