Flash84Z28

I just got my car drivable about a month ago after two straight months of dropping in the engine and tranny as well as a lot of other stuff. This past weekend I put on my Mac exhaust, fixed the torque arm bracket, and rear seal. Now it has a really bad stumble from just above idle until 2000 or so rpm. The idle is also pretty rough and lower than I'd like. Once above 2000 it is still kind of weak. A week ago it was fine.

I was thinking vacuum leak but can't find one anywhere. It does it both in park and drive, though not as noticable in park (higher idle). Also the A/F ratio seem okay becouse it show no sign of being rich or lean. The carb is a brand new Road Demon 650.

Any ideas? Your help is greatly appreciated!

Matt

todd200

Did you remove your distributer cap before you removed the torque arm to repair the mount? If you did, check to make sure it is installed correctly and you didn't bend or break the contact on the rotor or the wires are in order if removed. If you didn't remove it make sure it isn't cracked from hitting the firewall when the motor tilted.

Flash84Z28

No, I diden't even think of that. Thanks, I'm going out to check it now.

Thanks again,
Matt

Flash84Z28

Nope, still doing the same thing. I raised the idle but it is still pretty bad. Could a bad exhaust leak cause this?

Matt

todd200

I don't see an exhaust leak causing a bad stumble and low rough idle. If you are sure your ignition system is fine plugs, wires, timming,etc, start checking your carb. Mine did somthing similiar about a month ago. The car would idle fine but right off idle it surged and stumbled horribly until about 3 grand and it cleared up. As it turned out I had an actual "bug" in the carb. It was blocking one of the main jets and starving the motor for fuel until the secondarys opened. Start by checking your fuel pressure to help rule out a bad filter and to make sure you have the proper amount. 6 to 8 psi is what I've been told is normal. (I'm kinda new to carbs). Then worry about looking into the inside of the carb. Make sure your ignition is sound first! Might want to post this on the carb board also if you haven't already. Those guys know alot more than me.

Flash84Z28

Thanks for the reply! Last night I narrowed it down to the distributer. The plugs and wires are brand new and are fine. I took it apart and found a badly corroded ground terminal and corrosion about everywhere. I cleaned it up, sanded down all the metal and put it back on there a few minutes ago. Now it idles fine and there is very little stumble off idle. Amazing what cleaning up those metal contacts will do. I think my timing was a little off before too, so I statrted from scratch and set it to 6*. Now I can go out and enjoy the nice day, almost can take the t-tops off !


Thanks for the help,
Matt