BULLET99Z28

iTrader: (9)

after installing my ported tb last week, my car idles high-13-1400, then gradually comes down really slow to about 900, or if i'm in stop-n-go traffic, as soon as I push the clutch in all the way, teh idle goes way back up again and takes forever to come back down. Any websites out there showing how to check tps voltage,etc, or maybe a relearn procedure?

STANG KILLA SS 2

iTrader: (6)

mine does that to
but mine is cause of a too large IAH trying to compensate for the huge cam.

Shurtz8

I've got the same problem, just not quite as bad.

Shurtz8

I just ported my Tb too, by the way. I noticed a diff in acceleration too!

SUX2BU

iTrader: (14)

Whats a IAH?

JasonWW

iTrader: (2)

Why isn't there a sticky for checking the TPS and IACV?

I measured the resistance of my 99 LS1 TPS across the terminals and got:
B and C = 1,250 building to 2,200 and then goes down to 1,078 ohms
A and C = 1,290 building to 2,170 and then goes down to 870 ohms
A and B = steady 181 ohms

Does that sound right at all? I assumed the resistance in the TPS would build steadily, not go up and then down.

JasonWW

iTrader: (2)

Yep, the TPS resistance should scale smoothly up to 6,000 or so ohms. I replaced mine for $30.

Is there an easy way to check the IACV?

intense3123

I know TPS voltage should be under 1 volt at idle (somewhere around .6 or .7 volts.) And at WOT it should be around 4.6 volts. Try spraying the holes of your IAC with some electronic-safe cleaner like maf cleaner. Could have some carbon and **** built up in there.

JasonWW

iTrader: (2)

That type of testing requires a proper working car and you have to tap into the wires. I think it's easier to just check the resistance. That way you eliminate everything except the TPS.

In my case, some water got inside and corroded the traces on the film. (I opened it up and looked )

How can we check the IAVC? I've taken it off a few times and it doesn't seem to change it's position. I'm guessing that may be a test right there.

mjr_350

Not sure if this helps but over here when i had my old 3.8 V6 (now have LS1) you would turn the ignition to on but without starting and fully pump the accelerator 10 times to reset the TPS as to where it should be.

Im not sure if its the same for the LS1 though