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That's cool. BTW, how do you find the sniper? I'm interested but have concerns with reliability.Data stream is a wonderful thing. I believe it should be mandated that the driver can call up the data stream on the center console without any special tools or paywall. My Holley Sniper shows datastream on the handheld, and already I've been able to diagnose two failures just my looking at it.
IAC at 155 is going to lead to high idle speed. Question is "why is the IAC commanded to 155?" Does the IAC actually work?Truck warns up to op temp. CTS reads as it should. This is what I noticed on the drive, I was reading the scan tool along the way:
- Commanded desired idle rpm is 1000 rpm regardless of gear, or driving conditions. If I turn engine off, then restart it goes to 600-650 rpm, which seems more appropriate.
- The actual rpm at idle, in gear matches desired idle speed. However, in P/N is idles at 1500-1800 rpm. After the truck has been driven it slowly drops but only to about 1200 rpm.
- At the same time as this is happening, the IAC steps are 155. Really high. Spec is 5-30 steps at 525 RPM.
- Furthermore, regardless of gear, or driving conditions, IAC steps are always pegged at 155. Even cruising, 0% throttle, no AC, no lights or other loads. IAC reads 155.
Would this explain the high rpm at idle or high commanded desired rpm?
I wouldn't expect so. if the fueling is too rich, it should adjust the fuel trims, not add more air. I don't know why you have a Code 15 for low coolant temp, when you say the coolant temp is good.Another theory, could the ECM be opening the IAC Valve more, to add air, to try balance the rich fuel condition due to the Code 15, low coolant temp, aka add fuel?
"Integrator" is short-term fuel trim.What do the block learn numbers mean?
Will do.Clear the code, see if it comes back.
Your onto something here and again I feel it is the 410 CKT wiring as we've discussed.I dont think it is possible to have Code 15 with "CTS reading correctly" at the same time. thats weird. Code 15 is probably related to the demanded 1000 Rpm Idle. But it does not seem to be able to control, (not even trying actually) Idle Rpm, not sure why but the most obvious reasons would be a vaccuum leak or faulty IAC, in that order. The fact that it ends up at 1000Rpm in gear is just the converter lugging it down, the IAC at 155 all the time means the ECM is not trying to control Idle speed, not sure why, again maybe Related to code 15, as in it thinks the engine is cold, maybe not -40 any more since it starts but still not right.
Also, the ECM leaning out could point towards an Erroneous CT reading, in the way that the ECM is in the Fuel map block for a Coldish engine while in fact the engine is a lot closer to operating temps, where the engine needs less fuel. For that to be the case though the ECM would have to be in Closed loop, that is the only way for it to detect the Rich running, that again points towards CTS reading too low but not really cold, because i think it does not go into closed loop until the engine has warmed up some.