Sputters and then dies after rebuild

[krock26]

So I just got around to dropping my newly rebuilt B3 in about 2 weeks ago, and right away it had an idle problem.(It would only run over 2000 rpm) I didn't really have a lot of time to work on it recently, so fast forward to yesterday I start doing some research. I found a thread suggesting to unplug the coolant temp sensor and try starting it, and when I did it started right up and the only symptom was a fast idle. (~1250 rpm) I even drove it around the block a few times and in the driveway. Well I go out this morning to start it and all my problems are back. I went out and got a new coolant temp sensor and dropped it in, but still the same problem. The next thing I looked at was the IAC, in the Haynes book it says acceptable resistance is 7.7-9.7 ohms and mine had a resistance of 10.3 ohms. Could this be the cause of the issue? I can't seem to find a replacement anywhere but I can keep looking.

[krock26]

Forgot to mention, I pulled the plugs after the first start and they were gas fouled so I threw the old ones in and they got fouled right away too, so what could cause the engine to run so rich? The VAF moves smoothly, but pin 1 only has 5 volts going through it.

[milehighbear]

How about your IAC valve. Did you clean it out.

[ryanprins13]

I would say you have to fix one thing at a time. Replace the IAC first then see what happens.
Was this engine running fine before the rebuild or whats its previous history? If you were using it before and it ran fine what did you all replace?


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[krock26]

How do I clean it? Just carb cleaner?
And when I bought the car a couple months ago it did not run so I pulled the motor and just put it in a couple weeks ago. The PO said he heard it run and actually drove it but I'm not sure that's true.