Idle surges

Sorry I screwed up you disconnect the spout connector prior to starting engine make sure it's run with ignition and nothing else, set at 10 btdc then rshut off engine and reconnect spout. Then verify engine advances beyond initial setting. But your truck has to be over 8500lbs gvw and have eecIV if it's eecV then it's non adjustable. The only thing I can think of is the armature is on backwards and I dont' know how that could happen. I think that is what you call the stator

Shold be apic with this as I didn't see it in last reply

Timing with a light I covered in the previous answer directly from the manual. You may have to get this scanned. The dist teeth aren't worn down are they?

Does the problem go away when it gets warmed up after running?

It needs a pro type scanner as I mentioned in the previous answer as they can read by degrees. Auto zone scanners only read and erase codes nothing more. Besides the code they give may only be a code and not the actual problem that is wrong with the vehicle. What was the original code? If it was a misfire did you bother to check fuel pressure as low fp will give a misfire or lean condition code. Scanning and check fuel pressure should always be done prior to just changing parts, even if it is a n autozone type scanner.

Sounds to me like a bad IAC or a throttle body full of build up. Clean the THrottle body, and if you can post back a picture of the IAC I can tell you if it is able to be cleaned or not. The pintle in it should be free moving and the housing of the IAC should not be scored nor should the IAC.

Also check the Coolant temp sensor.

I would check the EGR valve. It can cause some of the problems that you are experiencing. You need to ensure that the valve opens and closes and is not stuck. This rascal should be located on the intake manifold.

Hello
Thanks for the donation.

The erratic idling is a symptom of a faulty idle air control valve. You say you already replaced this? It may also be a vacuum leak somewhere in the engine compartment. It is a new crate engine with 6k miles so I am guessing it was recently installed into your vehicle? If so then whoever installed the engine may have missed a vacuum hose somewhere.

Are there any engine codes popping up? If so, scan and post codes.. I do not believe the culprit is an O2 sensor, but if the problem does lie within the O2 sensor then the engine light would illuminate.

Hope this helps.
Thanks for using 2carpros. Com!

Since you DO have codes on, the first thing to do is to get those codes. You can have your vehicle scanned for free at most local part stores such as AutoZone, O'Reilly Auto Parts and Advance Auto Parts. Since the issue is only itermittent then it does seem like it would be more on the electrical side then mechanical, ruling out the vacuum leak. Post the codes you receive and I will follow up.

Thanks for using 2carpros. Com!

Great. Thanks for that info.
First off, the code 67 is - Neutral Drive Switch Circuit Open. This probably is indicating that the neutral drive safety switch is faulty and needs replaced. The purpose of the switch is to prevent activation of the starter (by creating an open circuit) when the transmission is in any gear other than P (park) or N (neutral).

Possible causes for the code 53 are the TPS is not seated properly, faulty TPS sensor (not likely since your sensor is new), faulty ECA, or VREF circuit shorted in vehicle harness. Double check the wiring and installation of the TPS and post your results. If you need some installation instructions for this component just let me know and I will post for you.

Hope this helps.
Thanks for using 2carpros. Com!