Another idle thread 89 240sx

[s13coupe88]

Hey sorry for posting another weird idle thread but I looked online for things to try and couldnt find one that matched my car situation.

Car info240sx s13 1989KA24E freshly swappedNew royal purple oil and K&N filterNew air filterI put in some fuel injector cleaner into the gas tankAutoNo air conditioning beltThe car does have a hole on the exuast, but its a fart cannon so im going to replace it anyways. Maybe the hole affects my idle.

My car is idling funny, when the car is in park or neutral it idles at 950-1100 rpms at the start but after a few seconds/minutes it goes up to 1500. When its in drive/reverse it idles at 750-850 rpms. I bought the car a couple of weeks ago and the engine was freshly swapped a couple of month ago. I knew the car was idling a high but i had a good deal and I just wanted to be in a 240 instead of a kia lol.

I honestly didn't understand a lot of what i read online but I tried lowering the idle from the ECU by turning the screw, but it didn't really do much.

What do you think the problem may be?

On a side note, i just changed the oil from some cheap oil to royal purple and the car idles 150 rpms higher is that normal?

[vancouverbc]

did you disconnect tps when you adjusted idle?

zerothread/254123

also, see idle -stalling in tutorials.

[s13coupe88]

Yea i disconnected it but I could not find the idle adjust screw that was in the picture.

My car is the 89 so its the single cam so i thought maybe its some where else but i couldn't find pictures for it.

I adjusted the screw on the ecu but it didn't seem to do anything.

I also forgot to mention the car doesn't have a exhuast manifold, i think... i have to check to make sure, would that affect my idle?

Also the car's idle jumps up and down 300 rpms

[vancouverbc]

the screw on ecu doesnt adjust idle. its for reading error codes.

Intake manifold SOHC