Actually the easiest way is to spray engine start or ether around the intake gasket area if the revs noticeably change then hey presto

 

Doesn't work all the time but it works none the less

 

That seemed to do it! changed out the intake manifold gasket (couldn't find a throttle body gasket locally) I've gained an inch or two of vacuum at idle, the idle is nice, smooth, and right where it should be. engine braking is also smooth and consistent. thanks for the help guys!

 

Good one

 

Bad news, the high idle is back with a vengance! Randomly will idle at 4k+ but its completely random. Sometimes it works fine, which leads me to think sensor issue. Also i'm having a random cutout issue where the car will be barely running and will die under any load. Please help me save this car from having to be replaced!

 

Oh... Duh, found the high idle issue. Cruise control cable nuts came loose and were tightening thus opening the throttle. The bogging issue remains though. Possibly fuel pump?

 

I checked the fuel pump (pressure wise) as well as the regulator and injectors. pressure is holding at 43 psi (with the vacuum line disconnected) and around 37 psi with it connected. when the engine is cold the pressure drops off slow after shutoff but after it's warmed up it seems to hold pressure for quite a while. with the problem being intermittent it sounds more like an electrical issue. I'm going to hook up a pressure gauge to the fuel line so I can see if it drops when the issue occurs just to be sure, but I would think that if it's a mechanical failure it wouldn't be intermittent would it? school is coming up as well so I don't have the money to just throw parts at it. any input?



again, the problem I'm having is seemingly at random the engine will lose all power. any load is out of the question and i have to keep at least 50% throttle just to keep it running. plugs and wires are relatively new, ignition coil resistance is within specs. triple checked TPS and the resistance is smooth with no dead spots. i have also installed a new crank position sensor. can't seem to find anything on hmaservice about this problem.

 

Can you monitor the MAF output? I recall a recall where they did something with the MAFs wiring to cure random low speed poor running/stalling action. If you can possibly swing a laptop and just record everything through the FIC's datalogger you might see something interesting on one of the sensors if the car acts up while you are driving.



Chain car parts stores will check your battery free. Possibly also your alternator. Can't beat free.



If there is any way you can get the problem to repeat on cue, you will be way closer to a solution. It can't be TOTALLY random, unless there is a loose connector somewhere.

 

it's the coil. started doing it during a drive today so i pulled into a parking lot and stuck something on the gas pedal to keep her runnin, it was misfiring badly so i started pulling plug wires to see if it was isolated to a certain cylinder. turns out cylinder 2 and 3 were both dead, no spark from the coils at all. limped home on 2 cylinders and sure enough that coil was way out of spec. after it cooled down it started up on all 4 and the resistance was much closer to specifications, must be due to heat. now the question is, do i get an oem replacement or do i try the gm coils i've heard of? hmmm

 

OEM lasted 12 years . . .