Surging problem

me too

i have a gt40 crate engine also with 30# injectors and a c&l mass air meter and i too am having surging issues sometimes not all the time....the thing sometimes almost cuts off and then surges up to about 1300 and then back to almost cutting off...then sometimes it runs perfect.....what kind of maf are you using i am using a c&l and i have heard alot of people saying almost the same thing

I have the same problem with my trick flow h/c/i and am running 24 pound injectors with calibrated C &L maf. I heard c &l ar junk. Mine only does it for about a minute after start up. Soon as I get the cash im gonna buy a diff maf

I am requesting this thread to be moved to the general tech board, as you guys won't get much help here...
http://forums.stangnet.com/showthread.php?t=698148

JR has done a great job with this thread...

jason

My first question would be 30# injectors? That's a little much I would think, how much horse does the crate GT40 engine put out stock? What throttle body are you using? I'm running a C&L and don't have a issue. I also have a tweecer with a custom tune I created. I had a warm starting surge issue, but I checked everything then realized that it's just plain to rich, so I cleared the start-up table (used as a multipler against the base OL fuel table) and then set the global fuel multipler to 1 (lower than 1 makes it richer, higher than 1 makes it leaner, 1 states just use what's in the OL table). This seemed to fix the issue.

So basically my thoughts are that first your running really rich because the computer thinks you have 19# injectors and the computer doesn't know the proper amount air coming through the TB as well as the correct MAF air flow thus, making it rich, (then the computer uses timing to keep the car running as a secondary if the idle drops to low) and your idle comes back then your rich again and it starts all over. (surging)

This is all assuming you are running a stock computer, sounds like you need to go and get it customed tuned to work properly.