Idle / Vacuum problem?

[rvnwlf]

I've searched but can not find anything quite like what's happening.

It's a 02 GP GTP with 170,000 miles.

When starting the car it will not stay running. Essentially the idle is to low. If I press down on the gas peddle 1/4" or so then turn over the engine the car will start and the idle will be around 1,000-1,500 and stay running. If I remove my foot from the gas peddle the idle will drop down to 300 and the car stalls out.

After reading other posts this is what I have done. I have already replaced the IAC (twice just in case one was bad), MAF (OEM), TPS (because after removing it and re-installing it was throwing a Check Engine warning).

Yesterday while driving I was hearing a whistling sound when the RPM's reached 1,800-1,900 under load going up hills.

Could that sound be a vacuum leak and if so could that cause what is happening. I'm not sure where to start looking if it is. All the hoses look fine. Should I just start removing all of the connections and check them one by one?

Any help would be appreciated.

Thanks,
Kurt

[iefalcon]

The rubber connection to the throttle body from the pressure regulator and purge solenoid, and the one rubber connection to the LIM on the passenger side, they can all crack along the time and temperature causing leak and spike whistling sound while the motor is turning. Especially the LIM one tends to crack underside. So they are the good starting points to begin with.

[J57ltr]

You definitely have a vacuum leak. There are several methods to find them.'Carb spray, unlit propane torch. Just b careful, make sure to check the inside of an elbow and the underside. Replace anything that seems loose or otherwise secure it. I used zip ties for a lot of the leaks I had. Remember each one adds up.

Jeff

[rvnwlf]

Thanks for the suggestions, is it safe to use the propain method on a warm/hot engine?

[J57ltr]

Yes, just put a hose on the end of the torch head and just barely turn it on, just enough to hear it when it's near your ear, but not as high as when you light it. Then move the hose to the air filter and you should notice the rpm change. Then start making the rounds of the points mentioned.

Jeff

[rvnwlf]

Sounds good. Where it will not even run sitting idle right now there shouldn't be any problems manually setting the plunger on one of the old IAC valves so it will idle around 1,000 and leaving it unplugged to do this testing.

[rvnwlf]

After running the propane test there were 5 different locations that the RPM's went up at/ I was able to use zip-ties for 4 of the spots and it looks like I will need to replace 1 hose. Even with just the 4 locations being fixed the will start and run idle on it's own.

Thanks for the Help.

[Scottydoggs]

if you have an advance auto they sell the best T's and vac line for like a buck a foot. the t's cost 2 bucks for two in a pack. they are little white t's.

call it 5 bucks and you've got 90 % of the lines changed.