" GRUMPYVETTE?
I have a TPI Corvette with the nearly stock TPI engine
My problem .Is I have a VERY high idle speed .. like 2500 rpm ..
Thing I have done .. replaced
EGR
IAC
TPS
Charcoal Canister
Took it to a Corvette specialty shop they can,t locate the cause
I no what some are going to say ...Vacuum leak ...can't find one ...neither the Power Brake booster line ...nor the PVC valve or line...make no difference if I pull the hose and place finger over the end..
Any suggestions?? "
a very high idle speed can ONLY occur when theres large volumes of air moving thru the intake , thru your throttle body, IAC or your intake gasket seals or an open vacuum line are the source of the problem..period
Id suggest removing the throttle cable and TV trans cable and adjusting the throttle body blades and IAC as a first test and get a decent multi meter to verify the engine rpms and tps voltage
you will find more detailed info in the links below
your simply going to need to locate the route the extra air flow is using, Id start with removing the throttle body and IAC and cleaning those and installing a new gasket on the throttle body and setting the IAC to specs along with the tps and idle adjustment screw and leave the throttle cable and tv adjustment cable disconnected until you locate the source of your problem, and read the trouble codes for any clues
WATCH THE VIDEO, READ THE LINKS
http://www.youtube.com/watch?v=9CPqbaSg ... re=related
http://redlinedetection.com/pages/video/
a propane torch is both safer and easier to use as a method to locate vacuum leaks
(DONT LIGHT IT) just SLIGHTLY open the valve so its allowing gas to flow at a low volume,start the engine and let it idle at the lowest speed you can then place the tip of the UNLIT torch at any suspected vacuum leak and listen for the rpms to increase and watch the tachometer, gas flowing into a vacuum leak will increase engine speed.
look for loose or missing vacuum hoses, cracked or broken power brake connections, emissions system hoses that are loose, vacuum connections to the trans or ignition, loose connectors missing or loose bolts cracked hoses missing assessory connections etc.
naturally this only locates leaks to the outside, and its possible for the intake to suck air from the lifter gallery, so that also needs to be checked if everything else seems to be ok.
read this
viewtopic.php?f=44&t=464
http://www.centuryperformance.com/tunin ... g-148.html
be aware that the lower runner gasket is not interchangeable between the drivers and pass sides of the engine on a tpi and if installed incorrectly that results in hard starts a big vacuum leak and an engine that won,t idle
http://www.harborfreight.com/lcd-automo ... 95670.html
READ THESE LINKS
viewtopic.php?f=32&t=168&p=202#p202
viewtopic.php?f=32&t=3518&p=9276&hilit=lars+idle#p9276
viewtopic.php?f=80&t=728&p=1243&hilit=lars+idle#p1243
viewtopic.php?f=39&t=617&p=20099&hilit=tv+cable+adjustment#p20099
viewtopic.php?f=44&t=882&p=1390&hilit=propane+leaks#p1390
viewtopic.php?f=32&t=168
viewtopic.php?f=55&t=3145&p=8395&hilit=throttle+body+cleaning#p8395
http://www.youtube.com/watch?v=zMok2y05 ... re=related
I have a TPI Corvette with the nearly stock TPI engine
My problem .Is I have a VERY high idle speed .. like 2500 rpm ..
Thing I have done .. replaced
EGR
IAC
TPS
Charcoal Canister
Took it to a Corvette specialty shop they can,t locate the cause
I no what some are going to say ...Vacuum leak ...can't find one ...neither the Power Brake booster line ...nor the PVC valve or line...make no difference if I pull the hose and place finger over the end..
Any suggestions?? "
a very high idle speed can ONLY occur when theres large volumes of air moving thru the intake , thru your throttle body, IAC or your intake gasket seals or an open vacuum line are the source of the problem..period
Id suggest removing the throttle cable and TV trans cable and adjusting the throttle body blades and IAC as a first test and get a decent multi meter to verify the engine rpms and tps voltage
you will find more detailed info in the links below
your simply going to need to locate the route the extra air flow is using, Id start with removing the throttle body and IAC and cleaning those and installing a new gasket on the throttle body and setting the IAC to specs along with the tps and idle adjustment screw and leave the throttle cable and tv adjustment cable disconnected until you locate the source of your problem, and read the trouble codes for any clues
WATCH THE VIDEO, READ THE LINKS
http://www.youtube.com/watch?v=9CPqbaSg ... re=related
http://redlinedetection.com/pages/video/
a propane torch is both safer and easier to use as a method to locate vacuum leaks
(DONT LIGHT IT) just SLIGHTLY open the valve so its allowing gas to flow at a low volume,start the engine and let it idle at the lowest speed you can then place the tip of the UNLIT torch at any suspected vacuum leak and listen for the rpms to increase and watch the tachometer, gas flowing into a vacuum leak will increase engine speed.
look for loose or missing vacuum hoses, cracked or broken power brake connections, emissions system hoses that are loose, vacuum connections to the trans or ignition, loose connectors missing or loose bolts cracked hoses missing assessory connections etc.
naturally this only locates leaks to the outside, and its possible for the intake to suck air from the lifter gallery, so that also needs to be checked if everything else seems to be ok.
read this
viewtopic.php?f=44&t=464
http://www.centuryperformance.com/tunin ... g-148.html
be aware that the lower runner gasket is not interchangeable between the drivers and pass sides of the engine on a tpi and if installed incorrectly that results in hard starts a big vacuum leak and an engine that won,t idle
http://www.harborfreight.com/lcd-automo ... 95670.html
READ THESE LINKS
viewtopic.php?f=32&t=168&p=202#p202
viewtopic.php?f=32&t=3518&p=9276&hilit=lars+idle#p9276
viewtopic.php?f=80&t=728&p=1243&hilit=lars+idle#p1243
viewtopic.php?f=39&t=617&p=20099&hilit=tv+cable+adjustment#p20099
viewtopic.php?f=44&t=882&p=1390&hilit=propane+leaks#p1390
viewtopic.php?f=32&t=168
viewtopic.php?f=55&t=3145&p=8395&hilit=throttle+body+cleaning#p8395
http://www.youtube.com/watch?v=zMok2y05 ... re=related