minimum idle rpm question

[88canadianvette]

what would the minimum idle rpm in N be for a 88" with a 4+3 warmed up?

 

[JonM]

500-600 RPM...controlled by the ECM

 

[c4ever]

I sit at 550-600. 500 was too low in regards to alt charging properly espcially with lights,wipers,etc. I did a TPS and idle adjust and she idles steady and never dips to 500 anymore.

Carlo

 

[vader86]

around 600rpm

 

[vigman]

550-600 is my 88 AUTO

In gear!


Vig!

 

[88canadianvette]

everybody is alot lower than me. im at 825 in gear outta gear...whats wrong with my car?!

 

[vigman]

Vacuume leak?

Mis adjusted cable, leaking throttle body ( around throttle plates).... Dunno?

What happens if you get under the hood and push the throttle plates closed?

Vig!

 

[88canadianvette]

when u say leaking around the throttle body..u mean air right?

i checked the throttle cable, everything seemd fine.

 

[vigman]

Right

I ment air... you can tell by grabbing the throttle shaft ( where the cable attaches )and trying to move it up & down. Not the way the cable pulls it though.

Vig!

 

[88canadianvette]

i ddi that..everything seem'd ok. car seems to rum just finre i was just always wondering why it seem'd to idle a bit high..as long as its not acting up i think i will just leave it...but that ac compressor is coming off as soon as i get the chance!

 

[vigman]

There is a set screw in the throttle body

it might be set to high.. and the computer is out of range... try backing it off a tad!

Vig!

 

[dan87vette]

Hi 88canadianvette,

Did you ever find out anything about your high idle situation? I've got the same problem with my 87... idles about 8000. I have set min idle speed and TPS a couple of times with no results. In fact, with the IAC closed and disconnected, I can't get it to go any lower than about 750, and that's with the throttle body screw backed out so that it doesn't even touch the throttle. Seems like it must be a vacuum leak, but I have been over it with a fine-toothed comb and found nothing. I even swapped out the throttle body, but the idle didn't change.

It's funny too, with both throttle bodies it is hard to tip-in the gas from idle. No matter how gently I try to feed in the gas, it will often suddenly jerk down, sometimes revving the motor to 2000rpm. Kind of annoying sometimes. With the engine off, the gas pedal operates smoothly. With the engine on, it doesn't want to crack the throttle plates open smoothly... like it's a vacuum lock or something.

 

[RedRagTop]

Hi 88canadianvette! I also have an 88canadianvette and idles around 620 or so, sometimes seems to drop a bit down depending on sitting at light with brakes on in gear (auto) but hasn't stalled out on me yet. If yours isn't too LOW I would be tempted to leave it. Most guys on these posts seem to have the problem the other way, car idling down to a stall. RJS
PS. Did yours come with the Canadian Climate Package (forgot code, at home)? What all does it include?

 

[silver 80]

Could it be just dirty throttle body? A lot of dirt not letting the plates close all the way. There is a section in vette mag pg 28 . It said that the most common problem being a high idle.

 

[Dcalebaugh]

Had the same problem with my 86. I adjusted the tps, tried the idle screw, not much helped. I finally did some research and pulled the throttle body off and cleaned it, along with the aic valve. Once done I disconected the battery for a sort time allowing the ecm to reset, hooked it back up and bingo, nice idle at around 600. It was at around 900.

Dave

 

[Daryllawman]

I have a 88 also and it stays around 600......:cool