I’ve had this problem where if I’m coming to a stop and put the clutch in the rpm’s will stay at about 1500 and then drop to idle once I completely stop. Anyone have any clues what it could be?

 

I think this is intended, with stock ECU/PFC the car idles at 1200-1500 while rolling and settles back to 750 when completely stopped. I've heard it's to make it easier to get into gear or something while you're still moving.

 

Check the clutch switch and clean ISC.

Dale

 

Please provide details on the vehicle's engine mods.

 

This has been the case with almost every manual car I've ever owned.
I assumed its normal.

 

LOL maybe this explains my weird idle. It idles high, and sometimes hangs higher after extended freeway use. ABS is deleted. Maybe there's nothing telling the car I've come to a complete stop?

 

Dash pot working?

 

The ECU gets vehicle speed from a sensor in the transmission, not the ABS system. That transmission speed sensor actually goes through the dash/speedometer/odometer which converts speed to a digital signal for the ECU. It's all spelled out in the factory wiring diagram, although it can be tricky to follow when a signal jumps from one page to another.

 

How would I check?

Good to know, thanks, crossing things off the list

 

More intended for the other bloke's symptoms, sounds peculiar that idle rpm would hang, but only while moving.

Process should be in the manual, if you download it, but that's not at hand for me at the moment. Typically when they stuff up, the push rod barely protrudes from the housing, normal is 8~10mm.