92 Z28 has me puzzled

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Ok, a friend has a 92 camaro 350 TPI, mostly stock, has headers, pulleys and thats about it.

the first thing i noticed was the tach said 3500RPMs and the scanner says 2500, the higher it revs the more OFF the tach is.

2nd thing, timing is set at 7-8* base, if you go full throttle it is at anywhere from -4 to -2 and it says the knock retard is at 20*!!

it is always reading knock, it has 92 octane fuel.

the knock sensor was unplugged and it still read knock and still pulled 20* timing out.

fuel pressure is at 42 at idle, anything higher and it runs like ****.

it shows a lean 100mv until about 3500 and then it goes to about 870mv durring a WOT run.

it hesitates, and feels like it is running lean.

the TPS checks out fine, the MAP sensor is new, and so is the knock sensor.


it also has MSD 6AL, new MSD wires and NGK plugs.


ive tried running 6* timing ive tried 9*, ive adjusted fuel pressure anywhere from 38-49.....

forgot to mention it has an adj. fuel PR.


any ideas of what the hell could be causing all the timing to be takin out? im guessing thats the reason its running like ****.


also, its a 92 so its speed density, no MAF.


any help would be appreciated greatly! its always the FREE jobs that get me the worse.... (damn friends cars)


thanks,


Joe

 

Disable the MSD box for the purposes of diagnosis. Once it is running properly again, reconnect the MSD box if you want.

 

so, i tried a few things:

i ran a bottle of injector cleaner through the tank, replaced the fuel filter, and i adjusted the TPS. At idle it was at .46 volts, i rasied it to .50 and it helped out ALOT, the car is so much better. The timing issue is still present, at WOT the timing is at -4* wich i thought it should be around the high 30's??

besides the timing being way retarded it runs alot better, doesnt hesitate, or feel really sluggish anymore.

i think the prom is f'd up somehow, and thats the next step.


anyone have a stock speed density prom?