LilJayV10

iTrader: (39)

A while back I did a H/C swap on my friends 93Z. Car runs fine but we have never been able to nail down the idle.

The cam is 230/236 from TEA with their ported heads.

I have messed with the idle screw because it idled to low. It will idle fine in park but when you put it in gear with your foot on the brake the rpms will start to rise some.

The throttle body is stock.

What do I need to do?

96capricemgr

iTrader: (1)

The computer is the ONLY way to adjust the idle. The only way you can change the idle with the screw on the TB is if you move it so far you max out the IAC's ability to compensate.

Stroked96Bowtie

iTrader: (22)

Exactly...does happen...I had mine hung too far open for a while gave me that same condition.

BALLSS

what you "need" to do...

have the PCM tuned for your new mods

DON'T touch the idle screw but since you have...it needs to be returned to where it was.

how do you do this???

you get software to now read WTF your IAC counts are...they certainly are wrong now if you have moved the screw around

the IAC counts want to be about 32 (30-35) WHILE TPS volts are .67 vdc with TB blades closed and 4.5 vdc full open. you can measure TPS with a volt OHM meter or with scan software.

In the end after you have done all of this you "may" have to drill the center hole in the TB out 1/64" more than it is now if your tuner can not get the car to idle right.

some open idle screw and then slot the 3 holes of the TPS to "trick" it and bring its vdc in range....I don't subscribe to this method but some do.

LilJayV10

iTrader: (39)

That's what I was wanting to know, to get it back where it was originally.