my car has been acting wierd for a few weeks now. at first it didnt start but i got that figured out. now sometimes when its idling when i first start it, the rpms will drop almost all the way down then it will stall. sometimes it wont stall it will just drop the rpms. it seems to be boggin abit when i step on it also. i was wonderin if it was maybe the fuel pump. i have no clue though cuz i have never had a problem with a fuel pump before, so i dont know the symptoms. im gonna get a fuel pressure gauge next week sometime and check it out. but i was just lookin for some opinions of people that might have had the same problem.
thanks in advance
corey

 

Kid,

So, how's the pressure? If it's fairly normal, you might want to look at the IAC and throttle body condition. A sluggish/dirty IAC can do that.

 

i didnt check it yet. im waitin till this weekend to pick up the gauge. what should it be at? can i check the IAC thing myself? thanks for responding. im tryin to get this cleared up. i havent driven the camaro in a few weeks and it sucks lol.

 

Fuel pressure with the engine running should be 37 PSIG ±3 PSIG. If you remove the vacuum line from the pressure regulator, the pressure should measure 43 PSIG ± 3PSIG.

You'll want to connect and disconnect the pressure guage with the engine off, just in case there is a bit of spillage.

The IAC and throttle body cleaning is fairly easy. You'll need to remove the IAC to service it. Remove the electrical connector from the IAC. Unscrew the IAC unit from the throttle body.

You can gently rock the pintle back and forth and allow the spring to extend it until it comes apart in your hands. Clean everything with lint-free cloths and a mild solvent. Harsh solvents can affect the insulation of the stepper motor coils. It's generally the dirt and buildup on this worm shaft that causes sluggish IAC operation.

When the worm gear on the pintle shaft is clean and dry, apply one drop of clean light oil to the shaft and work the pintle back into the rack gears of the motor by the same rocking motion. It takes a while to get the pintle back into the worm gears, but you'll get it. It is important to get the pintle fully retracted into the housing so that the pintle is not forced against the gears when reinstalling the IAC unit in the throttle body.

While the IAC is out, clean the air passages in the throttle body. The orifice in the TB where the IAC resides is the seat that the IAC valve closes against, and it can accumulate a lot of carbon, dirt, and debris. The easy way to do this is with carburetor cleaner and a small stiff brush.

When everything is clean and dry, replace the gasket if it is damaged, apply a little anti-seize to the threads, and torque the IAC to the proper specs. (13 ft/lb for '85-'89 , 30 in/lb for 1990-on.)

Only a little dirt and varnish can completely "kill" the response of an IAC valve:



This might help show you where to find the parts and what to clean:



When you finish the TB and IAC cleaning, you may or may not need to readjust the throttle position. If it hasn't been toyed with, it should be O.K. If someone has tried to adjust the idle rate with the throttle stop screw, you'll have some more work to do.

 

ok thanks vader. ill check the pressure and see what its at. if its where it is ill look into those other things. thanks again

 

ok i got a stupid question. i checked the manual about releasing the pressure on the fuel system and it says to pull the fuse. it said the fuse is in the slot marked fp. but i cant find one that says that. i looked in the fuse panel under the drivers side under the dash. if there is another fuse block somewhere i have no clue where it is. anyone have any idea where the fuse might be?

 

anyone have an idea where it is located?

 

The FP fuse is actually located on a wire up by the battery. (firebird) Easiest way is to simply unplug the connector back by the fuel tank (above the axle).

 

should i run the car till it stops? so theres no pressure in the line?

 

You really don't "need" to do that. If the car has been sitting for awhile, the fuel pressure will have bled off. Even if the car has just been running, just have a rag handy when screwing on the gauge. If you do it quickly, not much fuel will spill out.

 

I'm having the same problem as you it seems, let me know if you have any progress, thanks.

 

well i finally felt good enought to get the pressure. i was sick for the last few weeks, nasty bug i might add. the pressure is fine, right where the book says it should be. when i drove it today it just seemed like when i stepped on the gas it just didnt have the power it did before. would it be easier to take the throttle body off to clean the iac and the passages? or should i just replace the iac unit?