stock idle rpm's

is it suposed to idle @ about 2-300rpm?

88' 4.0, pukegoat, 4x4, 231

thanks

I believe it is 750

Remember the first mark on the tack represents 500 RPM.

Mine has always idled a little low, as a matter of fact both the 87 and 88 do. A couple of things to look at are the TPS adjustment, dirt in the IAC and the idle air bypass. On the drivers side of the TB there is an orifice (air passage) in the top, throttle air bypass, that can be adjusted by popping the round slug out of the side of the TB and removing the screw (torx) adjuster and cleaning out the passage, then reinstalling the screw adjuster. Keeping track of the number of turns when removing it, sure helps getting it back to the same position (I marked mine with a felt tip). You can try some fine adjustments, with the idle air bypass, but often the O2 sensor is gonna have the tendancy to adjust the idle back close to the original idle. When your done adjusting the idle air bypass, a little dab of gasket sealer will keep it in place.
Adjusting the throttle plate stop messes with the TPS adjustment and is a whole can of worms. Changing the throttle stop affects the idle RPM, but also changes the TPS setting which can also change the idle a little.
The O2 sensor can also affect the idle. as can the motor temp. sensor and, other things, there are a whole bunch of inputs for the idle (even in open loop cold operation).
I messed with my idle for months, making fine adjustments and finally ended up going back nearly to were it was and making sure my tune up was optimal so it idled a little low, but idled nice.

edmaude said:

I believe it is 750

Click to expand...

You are correct. It should be around 750rpm.

lol...oop's...i did a gauge swap to the tach (had all other gauges cept a tack) and noticed it was ideling a little low...after my intake install it idels higher now (i sprayed the carap out of the t.b. with cleaner too...so maybee i fixed something.

thanks