Alright, its a 305(as far as I know) tbi 1989 firebird. It drives fine and then all of a sudden the SES comes on and I get a code 43 and it drives like crap(retarded timing). Ok, so I replace the ESC, reset the computer and it happens again, every time I drive it. I have to pull over and turn the motor off and on and then it drives normal. I thought maybe that is what it is supposed to do and that I'm getting detonation, but I even switched over to 93 oct gas with octane boost and that didn't help. I know I can't disconnect the esc because that is what tells theECM to retard timing(no Voltage). Would it possibly help to disconnect the knock sensor? I don't know what to do.

 

I'm having the same trouble with my car. Someone else will know more about it than I do, but you might have a bad knock sensor or a bad ignition module.

 

I got real tired of that kind of ****, so I changed over to carb and now I don't have to deal with sensors and the headaches they cause.

:hail:IROC-Z

 

Ignition module is new.....I think I'm just about ready to swap over to carb myself, but I probably need this thing running halfway decent b4 I'll have the money for it.

 

try checking for a worn distributor cap. My car suffered variable timing and it turned out to be a broken dist cap.
Prem.

 

Oh yeah, I forgot to mention, do not disconnect the knock sensor. You will still have the same problem, that's what is wrong with mine. The Chevy dealership cut the wire that runs to mine so that I would keep bringing it in for repair. Damn crooks, now I have to run a new wire from the knock sensor to the ECM.

 

Thanks for the input, but I just did a total tune-up...Anybody else?

 

Same problem, same code. Replaced distributor and cap and wow it drives like new.

 

You replaced the whole distributor?!... Did you put in one with vacuum advance so you can bypass all the BS?

 

maybe you ought to try trouble shooting before you start replacing parts? you can put a resister inline from the knock senser to lower the knock counts, i've heard teflon tape on the threads works too.

 

And do you think the two might be related?

If the problem started after your "total tune up" there may have been a problem with the components you used.

Describe a "total tune up" so we might have an idea of what was replaced.

 

They are not related because I thought that the tune-up would fix the problem but it didn't. I did plugs, wires, cap, rotor, module, coil, iac, esc, oil change, air cleaner, and fuel injector cleaner. Also, I have been troubleshooting, My scanner reads 0 knock counts 95% of the time, once and a while it will pick up one, but never more than that.

 

86,

O.K. I wasn't clear on whether the problem surfaced before or after the tune up.

You may have a failing detonation sensor or wiring. You could try to replace the sensor with a 100K resistor (3.9K for S/D ECMs) to test the theory.

 

Nope, I kept the ESC. Turns out the distributor wasn't turning freely anymore either. The new dist came with a new ESC also.

 

Are you thinking of the ignition module? The esc is on the firewall behind the fp relay...I don't know why that would come with a distributor. It isn't even connected to it.

 

Oh sorry, yeah a new module came with the distributor and I replaced the ESC. I meant to say the ignition module came with the dist not a new ESC.