I have read EVERY thread on idle surging problems on this entire board!! Nothing helps. I am actually helping a friend (NufNuff) try to figure out the problem..Here's the problem, and everything we've done to try to eliminate it:

The car is an 86 IROC with a built 357..It had a high performance TPI on it, and ran fine for a year..All we did was put a Super Ram intake on..Now the car searches at idle from 500 - 1500 RPM's before dying..Here's what we've eliminated by either replacing it, or verifying its functionality:
Replaced Distributor, Cap, Rotor, Coil, Wires, O2 Sensor, TPS, IAC motor, Entire Throttle Body, New runner Gaskets, Verified no vacuum leaks through every possible method , New MAP Sensor, New Computer, Verified programming is correct, Tried every variable of chip programming suggested through the board, as well as others, (Even tried a stock chip) Ignition Timing is correct, All Sensor voltages are correct, Every ground on the ECM is Good, Fuel Pressure is good, Vacuum is good Map Sensor reads 50 KPA, TB Butterflies are open enough, Done all of the IAC Setup Stuff.....WHAT'S LEFT??..........EVERYTHING CHECKS OUT........So why won't it idle????

The only thing left is putting the TPI back on, and that'll cost the 3 tenths we gained with the Super Ram, but at least it will stop cutting off at Stop lights..
Thanks for any last ditch info..---Dusty

 

Anyone???

 

Did you make sure the super ram lid has a good seal?? Those can be a pain in the *** cause alot of them are warped out of the box!! You can call LPE and get the billet lid whitch will fix that problem. Other than that, I sounds like you have tried pretty much everything.

 

Have you checked to make sure throttle plate is tight? that actually happened on my old Bird, way back when it was a 2.8. Other than that, I'd make sure the air intake doesn't have a hole in it, and the IAC vavle is sealing. Otherwise your up poop creek

 

Yeah...I think I'm up the creek...No paddle..Tried 2 different Throttle bodies..Have the billet lid..Ugh..Don't know what else to do..Keep 'em coming!! All suggestions welcome!!

 

Update: Replaced the Intake Base gaskets.....No Fix..Any other suggestions????

 

Have you looked to the MAF and relays yet? Checked the injectors themselves? Simple stuff like burnt wires, fuel filter etc.?

 

Spped density car..No MAF.. Replaced MAP...and injectors..Now trying to do some more programming..

 

Did he convert with this engine swap or last year?

 

He converted last year...Everything worked fine then.. We think we may have stumbled on something...The desired idle on all the chips has been 550, so we think the computer is trying to make it idle down there ( which it obviously won't with this cam.) So we're going to try bumping that up to 800 or so, and seeing if that helps.. It was just an oversight I guess??

 

When you set the timing did you remember to disconnect the bypass wire first and then put it back together after? Also the bigger intakes like 2 to 4 degrees extra base timing. Just loosen the distributor, and advance the timing as much as 15 degrees to see if it makes the problem go away. Don't worry it won't ping at idle just don't rev it with it advanced. That will give you a diagnostic aid to see if it's a timing problem. Then you can set it correctly or back to where it was if that doesn't help.