I bought this car not too long ago.... the idle was really shot... it wouldnt idle on its own... I fixed that (TPS, vacuum leak repairs) but the car STILL feels like its missing alot of the power it should have. Any ideas? Its got a straight pipe instead of the cat, but thats leaking (a new cat will be going in soon) PLease help guys, I cant think of anything else.

Thanks,
Tris

 

lots of stuff to try.

unhook the knock sensor to see if that has any effect.

Check your plugs with an ohmmeter or replace them, same for wires.

Get someone to turn the engine over with a plug & wire removed from the engine to observe the spark... looking for weak coil.

Look inside your distributor cap.

Look for obstructions at your MAF if you have one.

Check throttle blade for full opening.

Check if your EGR is functioning properly.

Do a compression check on all the cylinders.
pull your valve-covers and check for rocker-arm adjustment, and observe rocker movement looking for flat cam-lobes.

Check your initial timing.


Exhaust leaks can cause a significant loss in power. The more leaks you have and the closer to the engine they are, the more power you lose.

 

Well, theses leaks are quite big ones... right where the cat should be. Throttle blades are opening all the way (I had the plenum off) MAF is clear, checked cap and rotor, clear.

 

at least look at all your plugs.

Is your TV cable adjusted & functioning properly? or is this just a problem with engine power?

 

I cant drive it yet... I did when I bought it (for two hours, to get it down here) tv cable is fine... better than fine... its just the engine. Oh, and another problem, when I start the car up, and idle it for a bit, and shut it off, then try to start it again... it almost always wont start... I have to wait for a while before it does... IDEAS?

 

Did you say you checked your base timing with the ecm disconnected ?

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1984 Camaro Z-28 LG-4
Q-Jet, dual snorkel air intake, underdrive crank pulley, Hypertech Street chip, SLP y-pipe and 3" cat back with hi-flow converter, Edelbrock Performer intake,Accel ignition. Running better now.

 

I'd do a fuel pressure test and see if you have adequate pressure and no leaking injectors.

 

yep good call on the fuel press & injectors. Sounds like leaks. Low power may be a clogged filter too.

 

Haha.. I will change the filter today... no, havent checked timing yet (my light is broken, gotta get another)

Thanks guys...

 

I am changing the plugs on the GTA now... some are fouled, black, wet, and smell heavily of fuel.... what could cause this?

 

If they're still wet with fuel I'd suspect leaking injectors. If it's oil you may need some valve stem seals as well.

 

NO, they were wet from cranking the engine over a little bit before I did the plugs... its easier to do them when the engine is warm, in my opinion (plus it keeps my hands warm too).

 

Well, did the plugs... she has a REALLY nice throttle response now! Sounds a bit smoother, and is idling a bit lower too... remember, I still have to adjust minimum air, IAC, and TPS, so idle will be even smoother after that. Keep the ideas coming!

 

I had the EXACT same problem with my GTA. Change the Ignition Coil (my crappy Accel blew after 5000km's). Car would start but I'd have to wait a while after turning it off. Anyway, I put a stock unit back on and have never had a problem yet!

Steve

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89 GTA G92
305 TPI WC 5spd w/3.45
Accel Cap & 8mm Taylor's
Custom 4" Cold Air Induction
Jet Airfoil
K&N Airfilter
160 deg stat/fan switch TB Bypass - Steel Rad
Cat back 3" Exhaust w/Terminator Muff.
HiGh FlOw Dynomax Cat
Spohn LCA's - KYB GR-2's
Autometer Vac+Oil Temp

 

Hmmmmm... a weak coil would explain alot too... including lack over power!

 

And the fouled plugs I just pulled out!