Ok Everyone, I have been doing search after search after search and I keep coming up with inconclusive information. I am determined to solve this problem and make sure others here on the board can solve a similar issue.

Heres the setup:
360ci, XFI280 cam (230/236), Brodix IK200, Accel Superram, Edelbrock HiFlo Base, 30# Inj, AFPR, DUI Distributor and plug wires, MAF, all emissions, anything else?

Problem:
I just built this motor, and I am having a b***h of a time getting this lil thing to idle. With TB closed (idle), it will start, but die immediately. If I put the corner of a rag or something into the throttle, it will idle around 600-800 rpms. Super rich, im crying in less than 5 minutes of it running. If I tap the throttle quickly, it will surge to about 3k rpm and come back down to idle. During this time I have set the timing to 6*. TPS is set at .49 (i have a question in regards to this). Tried to adjust the IAC, but it has proven futile. I disconnected the MAF and it perked up, idled fine, throttle response was there, but was sluggish in low rpms when driving around the block. I borrowed a MAF from a buddy to see if that would solve the issue, no dice. I have two IACs, used them both, but no change in performance. In reading about these, I understand that if you cannot recess the pintle, the IAC is bad. Both of mine recess with a good amount of force. Pulled TB and cleaned it extensively, IAC passages as well as Throttle Blade passage.
I have gone thru and looked for vacuum leaks everywhere I could with the given room I have around the SR and its runners... nothing. I do have a slight whistle however when it surges around the TB area for the first 2 or 3 minutes. After that it goes away. I cant quite reach the egr vacuum hose to check to see if thats the problem yet. I wired in a heated 02 sensor, dont know if that would effect anything. Im hoping I have covered everything that I believe could be hurting my car. Please help me to find the problem and solve it. I am trying to avoid throwing parts at the car to fix it until I know exactly what is making this happen. Tomorrow I will be removing the plenum and such to ohm out the injectors. I will be as descriptive in my responses as possible to make sure everyone understands what I am dealing with. Thank you in advance for your help.


TPS question.. if you have an upgraded cam and headers..blah blah, does the TPS need to be set higher or lower to accomodate loping and idle characteristics?

 

Come on folks... please give me a hand here.

 

OK, first off. If it will run with a rag in the corner of the TB, adjust the screw on the TB out some. That will substitute the rag.

-lower fuel pressure if you can

-bump the timing to 10

-Is this on a stock chip?

-Do you have 24lb injectors you could put in it for now? The reason I say this is if no tune, it thinks there are 24s in there and is dumping more fuel. your car needs no more fuel AT IDLE than it did before.

Can you make a video?

 

Idle screw is out all the way, I can lower fuel pressure.. currently at 42 and holding. What setting do you suggest? No 24s in my possession. Retuned chip for previous build of Hotcam, vortec heads, same superram, same injectors.

I pulled the SR plenum off this morning, ohmed injectors.. all come in at 14.6. I vacumm tested egr. It holds vacuum, but on the gauge it shows a slight bleed off, like 1inch every 12-15 seconds.

My mind may be playing tricks on me, but i was thinking about the coolant temp sensor and the MAT sensor and thinkin I may have swapped them by accident... doubtful, but still worth investigating at this point. What do you think.

I can put a video together when I put his lil a$$ back together.

 

Ttt

 

Set the TPS to .54v, see if this helps. The ECM is expecting .54v and a low setting will cause a loping idle.

Reset the minimum idle: jumper A and B on ALDL, key on, wait 30 sec, unplug IAC, remove jumper, start engine and adjust idle to 450-550, stop engine, reconnect IAC. Check/reset TPS again.

Look for vacuum leaks by grabbing vacuum hoses with your bare hand; if the hose leaves your hand black, replace them.

Whistling around the TB; is it a factory TB? I have heard that BBK's whistle.

The CTS and MAT are identical sensors, no problem there.

Your injectors may be leaking/dripping even if they ohm out ok.

Do you still have a CSI?

Hope this helps.

 

Ok.. I have put the car back together, I pulled the IAC out one more time to make sure it extended as it should when pulling the connector off in diag mode.. it extended. IAC is fine. I said before that I tried two MAFs with no result. Well I went back into the car and ran thru the fuses. I found that one fuse that controls domelight, horn, trunk pull down, etc. was blown. Turns out that same fuse also dealt with Computer Command Control! I traced the short to a stray bolt that landed in the cig lighter, grounding out the circuit. Removed bolt, changed fuse, fired car...It idles all by itself now!!!

Now it still idles rich as all hell and has a stumble when you tap the throttle, and an occasional surge depending on where the fuel pressure is. TPS is now at .55, havent touched the IAC, fuel pressure is at 40psi. Im hoping the rest can be handled in the ecm with a tune. Any other thoughts?

 

I traced some of my issue to a couple of bad plug wires. When I get those replaced, I will update.