briand069

Hi all,
I'm stumped at the moment. I am trying to troubleshoot this problem but have hit a road block on where to turn next. Car idles smooth, drives fine but when you hit the throttle at idle it hesitates then revs fine. If you go WOT off idle it backfires through the intake once. While cruising, going WOT it will backfire once through the intake and appear to run fine. I've attached a log of a run and it looks like the left side leans out. Rec #'s 4492,5328 & 5754 are just before it backfires when going WOT on the freeway. At the end of the file, 3-4 times at idle I hit the throttle and it hesitates. What I have tried so far is plugs, checked wires, opti is new but not replaced for this problem, fuel pressure checks out, compression looks good (within 10 psi) and I have checked for vacuum leaks and cannot find any. This is the LT1 in my 69. All emissions deleted, mostly stock tune from a Corvette. If anyone has time and can look at the log and give me some more suggestions I would appreciate it.
Thanks
Brian

http://www.gigasize.com/get.php?d=5wk5wmbxfkc

Injuneer

"Download Error - This File Has Been Deleted."

briand069

Odd. I just downloaded it again from another computer. Can you please try again?
If that one still doesn't work, try this one.




http://rapidshare.com/files/37825449..._run2.csv.html

Maybe this one will work. :/

Mystery Bird

I have recently developed the same problem. Adjusted throttle body for split BLM's and it got worse.

Injuneer

In your post "this one" is a box with a red X in it.

briand069

Well, I'm not sure what to try next for uploads. I can click on both links and download the file though. If they don't work what else can I try to host the file?

briand069

If someone wouldn't mind, can you please see if this link works.

http://www.mediafire.com/?zcwyt5zkzwt

Thank
Brian

Injuneer

It downloaded. Almost gave up when I clicked "download" and it popped up a hotjobs sign-in screen.

Huge file, will be a while before I can get to it.

briand069

Right on. Sorry about all the trouble posting the file. Most of the issues occur around the record numbers I listed but it you see something else let me know.

Thanks
Brian

briand069

Ttt

Mystery Bird

Mine went away when I pulled the coil wire, put some dielectrical grease on both ends and turned the throttle body screw out about 1/2 turn.

briand069

Well, I seem to have finally figured, well fixed at least, my troubles. After rechecking everything mechanical electrical I wet back to the tune. I had tried several different F-body bins and all resulted in the same hesitation/backfire trouble. The PCM I have came from a 94 Vette with the $EEB file but I could never get it to work because I didn't have the CCM. But, after downloading the most recent Tunercat I saw they added a option "Data stream fuel enable". So I reloaded my original tune with that option unchecked and low and behold it worked. I've read that loading the different bins shouldn't matter but for what ever reason mine seems to like the $EEB tune. Go figure.

Brian

mel0n666

my 94 z28 does the same thing...... i dont think it has ever not done it... i have just assumed it was because of the cam and because of the 2500 stall tq converter.