Checking idle speed

[Leung]

After getting my exhaust all hooked up, the Apex'i instructions said to rev my engine to 2500 to check for exhaust leaks. I found none but when i let off the gas, my rpms drop to around 300 and then catches itself.

My friend who was with me yesterday said i need to adjust my idle to around 800. In the Haynes manual pages 1-26 and 1-27 it says to hook my digital engine analylzer(i've got the same one in the image) to the tach terminal ( image 31.3 bottom left corner of page 1-26). The text says to hook the negative probe to the blue wire, where do i insert the postive? i'm guessing the other wire that's on the two pin connector.

The other thing is it talks about a "concealment plug" that's ontop of the throttle body. Image 31.7(upper right corner of page 1-27) is far too unclear due to it being black and white. Was there some kind of cover that went over the idle screw? because i don't see that "plug".

Thanks in advance.

[Cb7GHOST]

maybe its just that crap you have to scrape off that keeps the screw from turning

[NAiL05]

Do not use the adjustment screw. Thats really really last minute. Thats the last thing you should touch and last thing you should think of touching. Is any CEL on? If its before the o2 sensor usually it will throw something. If its after your just gonna have to follow piping. Using water or some sort or carb cleaner (dont go to liberal with this since it IS flammable) and listen for a change of tone. If you hear the exhaust tone change there is your leak.

[Leung]

oh no theres no exhaust leak that i know of, i'm only worried about when my idle drops down to 300 and then catches itself. that's why i'm whipping out the engine analyzer.

[Leung]

ok my guess was right, the positive was the other wire in the in that two pin connector(the blue wire was negative).

i got my idle adjusted to ~700rpms.


the only thing that baffles me is Haynes says to disconnect the IACV plug and then adjust the idle screw. when i unplug it my car cuts out. I ended up having to adjust the idle with the IACV still plugged in so i hope i did it correctly.

[Shay91Racer]

idk... maybe reset your ecu?

[Leung]

my battery sat unconnected for a day already. I don't think anything would have been left on my ECU prior to this adjustment.

I think i solved my low idle too.. the other day when we were revving the engine, my negative cable was loose( HEE HAW). Today i replaced the negative clamp with a newer one and tightened everything. Not once did my engine stumble like the other day.

[Shay91Racer]

hmmm... turn the screw...