rpms come down slow

[big reazon]

Here are my scanmaster numbers my motor is surging a little bit and the rpms are slow to come down after revving in park. These are all idle numbers.
af 06-07
L8 40-46
bat 14.0
int 128
bl 127
mph 00
clt 165
ats 63
r 750 to 1025
tps .42
iac 27 to 47
cc 00 to 216
nal 00
02 468 to 523

 

[jasjamz]

Turn you IAC screw in until you see .46 on the tps, see if that helps.

 

[big reazon]

af 06-07
L8 36-38
bat 14.0
int 128
bl 134
mph 00
clt 162
ats 61
r 800 to 900
tps .42
iac 53 to 57
cc 22 to 244
nal 00
02 468 to 523
Tried adjusting iac and got these numbers

 

[Eric Stage I]

Get the IAC down further, around 10-20 in park, hot.

When the surging happens, watch the BLM and see if the number is changing (switching between cells).

You might also consider resetting the ECM and driving around to let the BLM's relearn.

If the rpm's are coming down real slow in park, check to make sure your park/neutral switch is working. If it thinks its in drive, the IAC will come down slower.

 

[big reazon]

Will check the park neutral switch haven't driven the car waiting on shifter. Have tried lowering the iac but it will not go very low at all. I even bottomed out the idle screw spring and restarted the car to see the first set of scan numbers. blm wasn't moving with the surge at all from what I recall but I can check again in the am.

 

[TurboDave]

Turn you IAC screw in until you see .46 on the tps, see if that helps.

.46 !! NO, NO, NO. That value takes it out of the idle values.

 

[TurboBuRick]

.46 !! NO, NO, NO. That value takes it out of the idle values.

I thought .48 was the limit.

 

[TurboBuRick]

For now just ground the p/n wire.

 

[jasjamz]

I thought .48 was the limit.

It is for his Turbo Tweak chip...Dunno what Dave is freaking out over lol

 

[Razor]

If you open the blade on the TB the IAC will come down. Period. But while opening the TB blade with adjuster screw you must keep an eye on the TPS and keep it below .46. So its adjust TB screw.. then adjust TPS.. then adjust TB screw.. then TPS.. etc.. back and forth.

Me.. id open the blade screw like 1/2 turn(rpm will go up temporairily).. check TPS.. then go drive car so it can relearn. When you get the car back.. take a look again at the numbers. 1/4-1/2 turn adjustments then check TPS.. then go for a drive. You'll get it.

HTH

 

[TurboDave]

It is for his Turbo Tweak chip...Dunno what Dave is freaking out over lol

Not freaking out. It just bugs me a little when questionable advice is doled out. It's just that the "tipover" point from idle is about .46 on most. There's no need to set it anywhere near that high. .40-.42 is the ideal setting, once that and the IAC is adjusted properly and the problem still persists, then the P/N switch may be at issue. Possibly as simple as a mis adjusted shift linkage.

 

[big reazon]

Alright I guess I have to just drive the car to get the iac to relearn because i have let it idle in my garage until it got warm several times haven't driven the car still waiting on shifter.

 

[~JM~]

Would the IAC valve being stuck cause this problem?

My car wouldn't idle worth a damn for a while. I pulled my IAC & found it bound up & unable to move. I cleaned it & lubed it lightly & that seemed to help. I eventually went ahead & replaced it. Been good ever since.

Good luck
~JM~

 

[big reazon]

I have another throttle body I can swap on and see what happens got a couple other suggestions that I am going to try first.

 

[big reazon]

Still haven't driven the car found the park/neutral switch and made sure it was in park still had the same issue. I read on here that some have ran without an iac valve so I tried unplugging it and the rpms instantly shot up to around 2200 rpms on start up and stayed there don't know if that helps any.

 

[big reazon]

even with the throttle screw backed out to the point where it was not touching the throttle arm.

 

[Razor]

even with the throttle screw backed out to the point where it was not touching the throttle arm.

Wrong.

IAC = idle air control. Meaning the higher the number the more air its passing. If you need less IAC=less air passing= open the throttle blade. Backing out the screw closes the blade and increases IAC. Not decreases it.

 

[big reazon]

Wrong.

IAC = idle air control. Meaning the higher the number the more air its passing. If you need less IAC=less air passing= open the throttle blade. Backing out the screw closes the blade and increases IAC. Not decreases it.

That was with me disconnecting the iac. I put on another throttle body and my iac was still up in the 70s bottom the screw out opening the throttle body as much as I could without removing the spring and I got into the high 20s low 40s again. I posted a video and A buddy of mines on here said my rpms are normal. Now its just a matter of getting that iac number down its not the normal 1.5 threads that most use and it is outside what I can do without cutting the throttle spring but here is the video.

 

[Razor]

Drive the car and let it learn

Don't drive the car you'll pull your hair

 

[big reazon]

ok will do.