idle speed fluctuates?????

[lilkel]

every now and then when my vp V6 is started the revs shoot up to about 1500rpm stay there for a few seconds then come back down then go back up when i put the car into drive it normally drops back down to normal revs??? if i let it idle it comes back down on it's own too!! it's not the auto choke as it's doing it regardless if the cars been driven all day or it's the 1st drive for the day!! any ideas anyone????????????

 

[superchargedv6]

had that problem with v6 vr and it turned out to be the idle air control valve on the throttle body. took it to holden and they suggested pulling it off and cleaning with carby cleaner ( the valve that is ) as they tend to get a carbon build up and then put back on and reset computer to relearn the idle. didnt work for me cause i had to buy a new one for about $85 from holden but it may fix ur problem.

 

[greenfoam]

Also the car is supposed to rev higher when it first starts from cold, then it will slowly come down after X amount of seconds

 

[lilkel]

Also the car is supposed to rev higher when it first starts from cold, then it will slowly come down after X amount of seconds

but it does it regardless if it's the first drive of the day or the 50th! it does it when it feels like it! but not all the time!

 

[VTSSDUDE]

Yeah I say clean out your throttle body, take out t he IAC, clean the top part where the spring is. Clean the mounting where it seals up agains. Then see how you go. If not then replace the IAC.

Cheers,
Jim

 

[VpV6]

I think my VP used to do it..

You start it... usually when its hot... and the revs go to about 1400-1500 then about 5 seconds later it idles perfectly. When you put it into drive it makes a huge bang, because the revs are so high.

It wasnt the IAC, or the TPS, or the MAP, or the MAT, or the CAS, or the O2 sensor. Wasted about $200 replacing them all.....

Turns out that one of my injectors (is still) was a bit leaky. Since I had a really crap battery that cranked the engine over at about 1RPM it would flood a bit. Then when it started it would go up to 1500 to try to clear itself.

Replaced the 260CCA Massey "Ignition Plus" Battery with a Expanded Calcium-Calcium 560CCA Battery, engine now spins over at about 1000RPM and only gets to 1100-1200RPM then drops down quick!

Hopefully your problem is similar, but if you battery is OK.... then it may be something else!

Good Luck!!

 

[rip38L]

i'd say the battery is the problem because it's only about half the size that it should be so i'll get a battery and try that 1st cause i really need 1 anyway!