My IAC goes down to 0. I know I have a vacuum leak but its strange, the iac starts out normal then as the engine warms up it drops to 0 and a whistling starts up towards the back passenger side 2 injectors. The thing is it never idles higher than 50rpm above the target rpm. I know the throttle blades were cracked open because of a dirty iac passage. I have since cleaned out the IAC passage entirely and cleaned the motor as well as the throttle blade bores (took the TB off the engine to do this). I will be resetting the throttle blade stopper to try and get my iac counts up but what the hell is with the whistling at the injectors?

 

More than likely you have a an intake leak of some sort that is allowing air to be pulled in near the injectors.

I've have experienced an intake leak that allowed water into the cylinders until the engine warmed up. so it's not a stretch to imagine you have a leak after it warms up.

Why don't you do what mechanics have done for years with a thick lubricant in spray form. As the engine is warming up and you see the IAC counts start to fall, use a thicker than normal spray lubricant like PB Blaster and spray near the surfaces that could leak near the sound source. Then see if the sound goes away and what the IAC counts do.

And don't mess with the throttle stop.

 

Throttle stop is already messed with, I need to fix it. The previous owner cracked open the throttle blades rather than fixing the IAC.

And how exactly do I fix a vacuum leak around the injectors?

 

If its leaking past the injector o-rings, just replace the orings, there are like $2 for a set of 8.

 

I have the same problem with the 0 count, I also have a engine rev problem. I was going to check the fuel injectors, and replace the O rings. I did the following to resolve my problem and have not yet. When the rpm drops so does the count for the IAC.

I just tried the hose from the brake booster and still the engine revs/surges.

The car does as follows, you start the car and it runs normal for a minute then the car`s rpm increases to 2000 then drops down to 600, increases to 4000 then drop downs and continues to do so. It is a constant increase/decrease in RPM.

We have changed the following on the car. Some may not apply to this case.

A new opti spark accell
A new ICM module
A new Map sensor
A new IAC valve
A new PCV valve
New O2 sensors

We had the computer programed by Mad tuner.

The car was running good and one day this started. We have taken off the vaccum hoses from various places and plugged then and no change. The only thing that was not re-checked was the transmission, it was rebuilt one year ago. Some things may not apply just wanted to give everyone the whole picture. The EGR has been removed from the system re programing the computer. The vaccum hose from the internal heater and other devices in the car, when that hose was removed and plugged the car did not rev up immediately. It took a minute or so more then it did exactly the same thing as stated above.



PLease help if you have any ideas.


nash

 

intake leak intake leak intake leak when the comp sees target idle it will shut off or lower iac counts so it wont idle highif ya wanna find leak when motor is cold or when you hear the whistleing sound spray carb cleaner near it and u will hear the engine rpm rise when it does u have found the leak butt its prolly a intake

 

Well tried PB blaster around the injectors, saw nothing that looks like they're sucking (engine wasn't whistling at the time but the IAC counts were 0) backed off the throttle stop and IAC at idle is ~15 right now. I also redid the gasket for the top plate on the TB with sillicone instead of the single paper gasket that was there before that looked like it had been leaking. If its still leaking vacuum tomorrow once the sillicone is set il'l pull the injectors (what a bitch to do) and put new orings on.

 

If you think thats a bitch to do you had better sell your car then. It only takes 4 bolts to remove the fuel rails and then the injectors pop out.

 

Try pulling the fuel rails along with the injectors. plus theres o-rings that decide to stay with the intake, o-rings that decide to go down into the intake, all sorts of things to go wrong

 

I've had my fuel rails off more times than i care to remember. I've never had any of those things happen. I have SVO injectors and the injectors don't have clips on them anymore and when i pull the rail 99% of the time the injectors stay in the rails and don't even come out.

 

Thanks guys, I will check the injectors. I will change the o rings, and clean the injectors. If that does not work I will check for a intake leak.


nash

 

try doin what i said above and save yourself some agrivation and doin stuff it might not need

 

I will pick up some carb cleaner and give that a go.


nash

 

ya gotta diag it right otherwise your just wastin time and money and car is stillf+++ed up

 

It's not an intake leak unless my intake somehow got cracked. I sprayed water while it was whistling at the injectors and the pitch changed if you'd read what was said. The thing is i spray pb blaster and it doesnt suck it down.