New injectors.... Idle ?????

[BJMarshall]

Put in POD's on Monday. Once I got it bled and it cranked, it would hardly idle. Idle speed was terribly low. I adjusted the low idle screw until I got the idle back up to where it should be and locked it down. Since then, my idle speed has been dropping slightly. Any idea what is going on?

Barry

 

[Greenleaf]

You'll need to turn the fuel screw in a bit , little by little after driving it to monitor boost, smoke and EGT



Your new injectors take more fuel psi to pop so you now have less fuel at idle speed. By adjusting the fuel screw you'll be increasing the fuel rate (to accompony the new squirty things) and increase idle speed.



After above adjustments, then adjust idle screw.



Don't get too carried away with the fuel screw. There is a limit as well as much more effective methods to increase fueling. If I have heard this once I've heard it 100 times... . "My fuel screw is bottomed and my pump is maxed"



BJ don't do it. Take it easy and play it safe. When your ready for more power there are other steps to take.



GL

 

[BJMarshall]

Thanks Scott. I think I got the fuel where I want it for now. When I set the fuel and the low idle right after I put the injectors in, I marked them. Even without either of these changing position, my idle speed has decreased some more. I was just wondering if I may have a problem developing.

 

[bgilbert]

Nah , just more fuel and advance the timing about 1/32" of an inch since you have an early 91. Has your fuel pressure been checked ? Lift pump might be goin south. Can't keep up with the demand for fuel. Also make sure your low idle screw is locked down, it will back out, nut loosen, screw will have a mind of its own sometimes...

 

[Greenleaf]

yeah, them idle screws can take on a mind of their own... ... ... when you have the pump repaired/cleaned etc. and then operate the thing with a loose idle screw lock nut at say, 4,000 rpm's. The pump don't always want to return to idle speed

 

[BJMarshall]

Sorry guys, I messed this one up myself. In all of my adjustments, I had gotten the bellcrank linkage too tight, and it wasn't even hitting the low idle screw. Got it all set back right now and it seems fine. I'm sure none of you have ever done anything like thins before :-laf

Bill, I've got the timing bumped up a little already. Just shy of 1/8 on the factory marks. I feel like this is a little high, but I am going to set it right before I go back to the dyno.