80mm TB tuning issue
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From: The Chicken Ranch, California
80mm TB tuning issue On my initial startup of the day, my truck won't idle worth a crap since I put on the BBK 80mm TB. It fluctuates between 200 and 1000 RPM until I give it some gas and get a little warmer. After the first start, it's not as bad throughout the rest of the day, but it still idles like crap. Did the idle relearn process more than once, doesn't help. Changed idle control valves too. Ideas? TIA
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From: The Chicken Ranch, California
The TB was used, got it from a friend that never had any problems with it. The IAC motor that was on it wasn't working for me, so I put my stock IAC motor in it, no change. No codes so far, it's been over a week since I put it on.
do you have a cam? you may have to drill a bigger diameter hole in the top of the throttle body to allow more air to enter the iac motor chamber, not the blade, the hole that goes to the iac.. ive had to do it a couple of times and it fixed that problem, only after adjusting the throttle blade adjustment though... jes
Well, other than the IAC motor, I'd suggest also checking out your TPS, and MAF meter. I know a dead or faulty 02 could cause some issues there as well, but you'd have codes popping up. The same would go for a faulty TPS sensor-codes. I went through the same hell you're going through, and three separate times. But, this was prior to some experience. First, I had a bad MAF meter, second was a faulty IAC motor, and next was a front 02 sensor. All caused idling issues, but only one of the three problems didn't throw a code-the faulty IAC motor. If no one chimes in that happens to know for certain what it is, I suggest investing in one of the used TB's with sensors that are usually available in the F/S section. It'd cost you in the neighborhood of around $50.
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12 Second Truck Club
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From: The Chicken Ranch, California
I'll throw my stock TB back on and see what happens, that will help eliminate the IAC motor since I've used both IAC motors on the 80mm. Haven't tried swapping the TPS yet, but watching my TPS on a scanner it appears to be fine.
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From: The Chicken Ranch, California
New info which confuses me even more. I have remote start on my truck, have always had it, never had this issue before TB swap. Now, when I remote start it, the key not in the ignition it idles fine, TPS in scanner shows 0, IAC steps show 0, perfect idle. I put my key in the ignition and turn it on, TPS goes to 2%, IAC steps start fluctuating between 3 and 8, crappy idle. I've swapped TPS' and IAC motors, same thing either way. Even did the TPS relearn thing like Another User instructed to get the TPS back to 0 in his other post. Will try putting stock TB back on and see if it still does it. Let me know if you have any ideas with this new info.
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From: The Chicken Ranch, California
Swapped back to stock TB with the same electronics as the 80mm TB, idles perfect with or without key now, TPS 0, IAC Steps hover right around 50.
lol, yup.... thats why i normally just pull them off, or modify the hole... damn aftermarket stuff....