I just got done swapping a built short block and stage 2 cams in my Lightning. The engine is running now however it is not idleing properly. When you put it in gear the engine wants do die for a second. Also the rpm is pretty jumpy and the engine shakes like there is a misfire but then when you are driving it there is no sign of a misfire/no backfires. Only when it is idleing is the missfire like condition present.

I checked the IAC and even swapped out one on my friends truck, So that is out of the question.

TPS is right on a .989 v with Accufab

Vaccum lines are good however the vaccum on the guage is at like 15 or so Inches of mercury. Used to be 20 but that could be the cams.

Fuel pressure is good.

I am going to check the plugs but I dont think that could be the problem. I switched from It 22's to It24 gapped a .035

The thing is the truck runs great other than low RPM Range. What else could be my problem.

Please help me out ASAP
THanks
Zach

 

If the needle is steady at 15 and not jumping I would agree that you don't have any leaks. However if it is jumping around you may have a small leak.

I suggest this with some reservation so please be carefull.

I have chased down vacum leaks in the past by taking spray can carb cleaner with the small red straw and spraying it around the manifolds gasket area's.

If the engine speed increases or changes it would indicate a leak there. Just keep it away from the air intake and squirt away.

The only other thing would be to double check all your electrical connections which I am sure you have done about 20 times.

You might try driving by a church tomorrow since it is sunday
Good Luck

 

Could it be that the engine Rpm is just too low for the stage 2 cams? I am running the same program do i need a retune for the cams?

 

what's your engine idling at?

with my new motor (crower stage 2 cams) the thing cut off at idle sometimes. when coming to a stop and turning at the same time (like a u-turn) the truck would die in the street. sometimes if I left it idling to warm up or whatever it would run fine for 5 minutes and then out of nowhere just die.

I believe Sal bumped up the IAC% on my last reburn and since then (over a week) it hasn't cut off once. has a rough idle due to the cams, but not cutting off anymore. hope this helps. also, normally I don't recommend messing with the throttle body stop, but you might try doing that to open up the throttle blade just a hair in order to raise the idle.

good luck.

later,
chris

 

Hey superfords how did you go about breaking in your new motor? It is idling around 600-700 RPM should the engine be shakey like a missfire at idle?