Carb Question

[eazyj]

Does anyone know if the Rochester dualjet is supposed to make any noises when you turn ignition to on?

 

[darbysan]

If you are still running your ECM, you will hear rapid clicking form the passenger side of the carb. This is the Mixture Control Solenoid, and the sound is supposed to be there.

 

[eazyj]

Thanks man. I've tried two different carbs and neither of them started clicking. Do you know what might cause that?

 

[darbysan]

Could be just bad luck ( MSC bad on both carbs). Likely a bad ECM. You can Ohm the MCS in the carb. If it has resistance, it is probably OK. If it is Open, then the solenoid coil is bad. Have you pulled codes from your ECM? A code 12 means the ECM is "OK". Could also be a broken wire between the ECM and the MCS, or a bad connection at the ECM. Time to play "spark Detective"

 

[eazyj]

The thing is that my car will turn over but it won't start. I've checked the ignition coil, the ignition control module and have tried 2 different ECMs and 2 different carbs. What's weird is that the car will start if I unplug the distributor.

 

[darbysan]

Unplugging the dist puts the ECM into limp home mode ( Full Rich on the carb, so no clicking). It also effectively retards the timing back to your base timing. Assuming you set your timing with the dist unplugged. If so, it's possible that the 1) dampner has shifted, moving your timing mark, so that the timing you set is not really correct 2) the timing chain has jumped a cog 3) the distributor is maybe messed up inside ( don't know on this one).

 

[eazyj]

I haven't messed with the timing. Ive tried a different distributor and it didnt start.

 

[darbysan]

Sorry, I'm out of ideas. Maybe someone else can jump in