I've had many problems with my car since I've bought it, but overall it's a solid vehicle. This past winter I replaced all gaskets, belts, and a few hoses. Shortly afterword the car was losing power and running like crap after a minute or so. Some days it would run fine all day, others like crap all day. In this time I replaced my O2 sensor, replaced fuel filter, checked my MAF sensor, and replaced my EGR valve after a code 32. I finally had a friend run diagnostics on it, and he determined it to be a stretched timing chain, jumping around on me and said it was 30 degrees off (!!). I replaced the timing chain and gear, set the timing and got things nice and tight. The car now runs fine, but it still feels weaker than it should and throttle response is less than good.

When I open the throttle i hear a 'ffffffwt!' air sucking sound that lasts about a half second before it revs up. I can't find any missing or disconnected air lines. Computers not throwing any codes, only mods are K&N and throttle body airfoil. Ignition system is in good shape, new plugs and wires, it idols perfectly.

Any suggestions or advice would be great!!

Thanks

Mike T

'91 GTA

 

MD,

Welcome Aborad!

Where is you base ignition timing set?

What is the idle vacuum reading?

 

Timing os 6 degrees before top dead. How do I read my Idle vaccuum???

Thanks!

Mike T

 

MD,

You'll need to connect a vacuum gauge to an intake manifold vacuum fitting (like the HVAC or FPR connector) and read the vacuum directly. Hot idle vacuum on a stock engine should be around 18" Hg, and the indicator needle should remain rock-steady with no dither, wandering, or bounce.

 

What will this reading tell me? What could the results mean??

Thanx

MikeT

 

Low vacuum can mean a valve timing problem, worn cam lobes, poor valve sealing, or a vacuum leak. A bouncing needle on the gauge can mean a sticking or damaged valve, bad cam lobe, tight (pumped up) lifter, or gasketing problem.