my car idles like crap. if im stopped in gear, it will stall...if i put it in neutral, it barely wants to run and the idle surges anywhere between maybe 650 and 1100, so i dont think it's the idle speed. if i put the car in gear and give it light steady gas, it will go for a sec, stumble for a sec and then go. if i go above maybe 1750 theres no problems, still puls nice and hard and runs like it should. but it gives lots of trouble at idle. ive been thinking about possible problems:

Vac leak: all the vac lines are fine, except maybe a line that runns to the tcc switch, that line goes under the car and the switch is right next to the trans, could have come unplugged but i doubt it. i also have a home-made egr blockoff which may leak, but i have a real one on order that im gonna put on. also the carb gasket is new, been on there for about 4k miles, as long as ive had the engine in.

spark/timing: i dont know what the hell the timing is at...its different every time i check it, but i think its cause the damper is old and the outer ring slips. otherwise, everything in the dist. (including the dist. itself) is 4k miles old, havent looked at it since i dropped the distributor in (correctly...it ran fine until now) and i dont think there should be a problem in there

fuel: the pump is 4k miles old, the filter is liek 2 days old. the carb is an edelbrock that was on an old blazer i bought. im gonna rebuild the carb on saturday hopefully. maybe thats my problem right there. but otherwise i dont see anything else fuel related causing this

last night i re-set the choke, its working fine..opens all the way. i also cut open the pcv line and put a tee in, which runs to the charcoal canister, this has been disconnected since i put the motor in. the problem was present before i did this, but now it seems a little worse...

any ideas?

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350, Comp 262, Edelbrock Performer intake 600 cfm carb and exhaust, headers

[This message has been edited by CamaroZ_85 (edited October 31, 2000).]

 

Well, an IAC can do that when its on its last leg. Also check your TPS. Make sure its not fluctuating volts.

OOPS, your not TPI......LOL Disregard

[This message has been edited by UB-HSTRY (edited November 01, 2000).]

 

Well, it could really be a million things. First off, i don't know what you mean about the TCC switch, unless you've added something aftermarket, no 700r4 has any kind of vacuum lines connected to it The TCC is controlled strictly by the ECM. Still, don't rule any vacuum leaks out, make sure your carb is tight, and the same for al the lines. Spray everything down with carb cleaner and listen for the engine speed to increase. If it does, something in that area is leaking and NEEDS to be fixed.
Other than that, it could be anything ignition related. From worn out tune-up components (or fouled plugs) to a beat pick-up coil. You need to get a handle on the timing too. If you can't accurately check/measure timing you're just playing with your **** .
Fuel related, probbaly not. BUT, when did this problem start. If it started fairly recently, they just made the switch to winter formula gas which could be causing your problems as well. MPG and performance suffer with this crap. Combine winter gas with dubious timing and it'd be even worse.
...ed

 

Your car won't have a vacuum switch for the TCC unless it's originally a Canadian car.

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1984 Silver Z28, 383 cid 4 bolt, ARP Fasteners, 2 1/2" Cowl Induction Hood, 600 cfm Performer Carburetor, Torker II Intake, Performer RPM Heads, XE268H Cam, Magnum Roller Tip Rockers, MSD6AL Ignition, Blaster2 Coil, Recurved HEI Distributor, 700R4, TransGo SK, 2.73:1 Limited Slip Dana 44, Terminator Headers, Custom 3" TIG Welded Stainless Exhaust, Flowmaster Muffler, 4 Wheel Disc Brakes, Oil Cooler

 

the vac switch is aftermarket, came with my tci lockup kit, which i installed since i ditched the computer. and i found what the prob was....at first the carb base was leaking. changed the gasket, put on the egr block and it still ran like ****. sprayed around and found the carb itself is a leaker...gonna rebuild it sat. thanks guys

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350, Comp 262, Edelbrock Performer intake 600 cfm carb and exhaust, headers

 

What do you mean spray everything down with carb cleaner?? How does that help detect leaks??
Reason why I ask, I think I have a vacuum leak somewhere, and I am looking for the best way to detect leaks. I have a TBI system, can I spray it down or what??

What does TPS and TCC stand for??

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Godti
'89 Trans Am (Red)
305 TBI 5spd

 

What you do with the carb cleaner is run it along places where gaskets meet. If you know that you don't have any faulty vacuum lines, the leak is in a gasket somewhere. Take the carb cleaner, and with the engine running, spray it along the tbi base, the manifold base, and any other places where a vacuum connection is made. With the engine running, the carb cleaner, if it finds a leak, will cause the engine to bog down. I recently had one where the TB meets the manifold.

TPS is the throttle position sensor, located on the Throttle body by the IAC.

TCC is the transmission converter clutch. I think its located between the tranny and the engine, on the fly plate or someplace, i couldn't tell you for sure, but from what i'm told its a pain in the *** to get at...

GOod luck,

Mike

definatly check the TPS... it could be going...


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1989 RS.. Newly installed 350,bored out 30 over, Hypereutectic pistons, double roller cam, double roller timing chain, accel wires, blue streak cap and rotor, platinum plugs, chevy caprice 350 chip.

 

if you spray your leaky carb/throttle body with carb cleaner, the cleaner will temporarily seal the leak, which will make your idle smooth out or increase. doing this allows you to find where you have a leak. example...i sprayed around the base of my carb and the idle jumped up...that meant the base gasket was leaking. after i replaced it, i still had a poor idle, so i started to spray down small areas of the carb to look for leaks. my carb has a top plate that comes off...which is sealed with a gasket. i sprayed around that gasket and the idle smoothed out again. so to fix my problem, im going to rebuild the carb this weekend. of course you need to check all your vac hoses first, as this is a more likely place for a leak to occur. TPS stands for throttle position sensor, which is only found on computer controlled fuel systems (TBI, TPB, MPFI[multi-port fuel injection]) it tells the ecm how far the throttle is opened. I dont deal with this since i have a carb motor. TCC refers to the system controlling torque converter lockup.

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350, Comp 262, Edelbrock Performer intake 600 cfm carb and exhaust, headers

 

Actually, the old trick was to use Starter Fluid. If there was a vacuum leak, it would suck the fluid in, causing the engine to race a little. Carb cleaner is probably safer though

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Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Appretiate the info. Not to many people respond to my questions.
Thanks


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Godti
'89 Trans Am (Red)
305 TBI 5spd