Raptor99

Put on a ported TB today, and now my idle is high. It normally runs about 500rpms, but now it's around 1,000rpm. Not only that, but it's like it has cruise control on all the time now. I'll be driving along at 30mph, take my foot off the gas, and it'll stay consistant Something wrong?

xfactor_pitbulls

iTrader: (16)

Funny you put this thread. I was going to start one too. After my install, which is everything in my sig, mine idles at around 900. But when you are coasting down it sticks at 2K. I think mine is due to the fact that the throttle body is drilled for the cam and is still letting too much air in due to movement of the car. Is yours drilled as well?

Brandon

Raptor99

I'm not sure if mine's drilled, I'll have to check it tomorrow. I got it used from a board member, so who knows

jimmyblue

iTrader: (11)

Make sure the idle stop screw is backed out enough
to seat it, and that you do not see daylight past the
blade when closed ("lumpy" daylight would mean the
port-job munged the seating circle). But I think that
"cruise control" more likely means vacuum leak (check
the TB-manifold O-ring), overdrilled hole, cables too
tight (hanging the TB slightly open) of crap in the IAC
that keeps it from seating. Seems to be a high incidence
of plain bad IAC motors when dealing with the fancy
powder-coated "professional" TBs. Might swap your
old IAC servo on after blowing out the IAC bore and
checking the seating circle for crud.

jimmyblue

iTrader: (11)

Make sure the idle stop screw is backed out enough
to seat it, and that you do not see daylight past the
blade when closed ("lumpy" daylight would mean the
port-job munged the seating circle). But I think that
"cruise control" more likely means vacuum leak (check
the TB-manifold O-ring), overdrilled hole, cables too
tight (hanging the TB slightly open) or crap in the IAC
that keeps it from seating. Seems to be a high incidence
of plain bad IAC motors when dealing with the fancy
powder-coated "professional" TBs. Might swap your
old IAC servo on after blowing out the IAC bore and
checking the seating circle for crud.

Another_User

While we are on the high idle subject, if your idle is high beyond the IACs capability to adjust, will the PCM pull the maximum amount of ignition timing that it is allowed in order to try and bring the idle down?

NLang

iTrader: (12)

Just back-off the idle set screw and slam the thing closed a few times. Do this until it sticks and then give it a 1/4 turn back in. Be sure to reset the comp by pulling your negative. Either the person who ported the unit didn't do this before sending it off, or the person you bought this from screwed with it.
I bored hundreds of units for all makes and models a couple yrs back. Every now and again, one would slip through the seat test. Just one of those hard to 'see' details.

Raptor99

I just talked to the guy I got it from, and it sounds like I need to twist the screw in a little more, because he backed it out a tad to compensate for his cam. Just in case that's not enough though, how do you loosen the throttle cable?

'Trust'

iTrader: (24)

Make sure he didnt port under the blade too!

NLang

iTrader: (12)

No no no, not twist in, twist out. You want to loosen the screw to let the blade close more, you don't want to open it more. That's what's causing your high idle. The guy must have tightened (turned in) the set screw to compensate for the cam. If he had backed off from the factory setting, it'd provide less air, or just stick when shut quick. You're backwards...

Raptor99

Yeah, my bad. I knew what to do, just worded it wrong

I got everything worked out though. One and a half turns got me around 600RPMs again for idle. Had to reset the PCM fuse though to ditch the code. Thanks for all the help guys!

NLang

iTrader: (12)

Ragtop 99

iTrader: (7)

He didn't!