Any tips? I've sprayed carb cleaner all over the place. No changes. I've replaced the IAC and TPS. New used EGR solenoid, but my problem stayed the same. I've replaced all the vacuum lines that I can get to with red silicon lines, all the ones I can get to without taking off the upper plenum. I'm starting to think maybe its a small gasket leak somewhere, but 1900-2300ish seems a bit high for a small leak.

Any suggestions? For a while it would only be high one it was up around operating temp, but for the past week its been goin all the time.

 

First off, get yourself a MityVac (it will save a lot of money later) and hook it up to the small side of the T in the back of the upper plenum, where the booster hooks up. Then, if you're reading much less than about 14 or so" Hg, then you have a vac leak. If not, you need a digital multimeter (or DMM) and hook that up to the TPS. You should be reading around .55 VDC between the blue and black wires (whichever those are on your engine). If that's off, and you can adjust the TPS, adjust until you have the right reading. Now, if the idle is still high, adjust the idle stop screw, the screw that is against the cable side of the throttle lever at the top. Adjust until you get around 700 RPM hot (and in Drive if you have an auto, dont forget to set the parking brake and block the wheels, manual should be in Neutral).

 

Shops can test for vaccum leaks pretty easily and cheaply. One guy here locally put smoke through my system and I had leaks that I thought I fixed or didn't know about. Also check your injector o-rings. Those caused me bad leaks.

 

Injector O-rings causing a vac leak. That's one I haven't heard yet.

I've wanted to buy a digital volt-ohm meter for a while just to adjust the TPS but haven't gotten around to it. I've been just starting the car, moving it until I get a good sounding idle and screwing it there , lol.


Smoke through the engine...that sounds like a great idea, too, since I've probably got some manifold gasket leaks somewhere and others.

The engine was supposedly rebuilt about 10 years ago, but from the looks of it, it was probably done by some mountain men with a just a wrench, a screwdriver, a Hayne's book, and an urge to cheat people outta their money.

 

I had some vacuum leaks on my ride and was driving me nuts..the brake booster was leaking which is an easy test,either unplug it or step on the pedal while its running and if the rpms stumble or drop its probably bad.The other one was the Vapor canister solenoid ..it was stuck open creating a vacuum leak.Unplug the hose from the solenoid and either use a vacuum pump on it or put a hose on the fitting and blow through it.Shouldnt be able to blow through it(solenoid in closed position) the computer opens it at a certian rpm to let fumes in..So thats something to consider if you havent checked those yet.The smoke machine is an great set up, we use at our work for those times we cannot find a small leak.Good luck

 

I didn't even know there was a solenoid on the smog canister


My RPMs drop about 200 if I pump the brake hard while at a stop. But they climb soon after I stop. Sound like a problem? I always thought that was normal.

Anyone know what kind of popular shops might have this smoke machine thing? That's actually got me excited.
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Which opening on the solenoid should I not be able to blow through? Or is it all of them?

How'd you replace that one? Do places like AdvanceAutoParts or AutoZone carry something like that? I wouldn't think so. Something to get at a junkyard probably?

 

If you start the car up ..let it idle and step on the brake the rpms shouldnt drop..or if the engine starts to stumble.The booster is leaking..it has a large diaphram and its like a large vacuum leak...usually the car will die when your driving coming to a stop.The solenoid sits right on top of the can ,unplug the large line to it..one that comes from the engine.Install another rubber hose onto the fitting and blow through it.You shouldnt be able to blow through it..if you can its stuck open..The smoke machine can be purchased through Merles ..dont know if you have one in your area..I think it runs around 800 bucks (not sure) but remember seeing it.. in there catalog.Might want to try a tool company like Snap-on,matco..etc.Oh the solenoid itself isnt available ..you must purchase the whole canister..unless you can find one in a junkyard..I seen the same one on a olds cutlass...

 

I need to check out that solenod too. I have been chasing vac leaks for a while and I think that I have gotten most of the big ones.

 

Valves adjust wrong, lifter(s) bad, camshaft rounded off all cause vac leaks too.