Help, engine runs really bad
 

77 C3. The engine from cold to warm runs really bad. It will hardly idle at all on its own, it backfires from the pipe, backfires on any type of deceleration. With foot on the gas it runs strong and really pulls nicely but if I release the gas in gear, it putters and backfires. The engine also seems to be running 10c warmer than it did last season. I had the car shut down for almost a year while I was doing a paint job. It is strange that it would run warmer since when it was shut down I had the pipes going to the front cooler fixed.

I am ruling out the auxillary air valve since it would either run good cold or bad at some point in the warmup.

Would n't the same thing applie for the WUR, at some point it should run good.

How about the start valve being stuck open? That is open for only a short period of time so that maybe it is stuck open feeding extra fuel,

When I put the car away last year, it ran great.

I am ready to roll the car off a bridge seriously.

David

probably bad gas (old) put a inj/carb cleaner and an octan booster then check points gap.

you need carbs.

sounds like timing or bad gas; or both.

Bad gas might make sense. Right before I started having problems, I filled the tank. After I drove the car another five miles and then dropped off for the day, it suddenly started running like crap when I picked it up that evening. I will check it out.

Would bad ags make the car die when driving? When I was driving home from the mechanic yesterday, about five minutes in the engine dives while driving. I was driving along with the rpms around 3000 and I notice the rumble of the motor just stops. I put into neutral and the rpm's drop to zero. Engine is dead. I pushed home with my other car and got it to start while pushing in gear. Ran great with rpms up but again, did the same things it did before at idle and deceleration.

Thanks,

David

That sounds a little like a problem I once had with my '82 SC. Most of that problem turned out to be vacuum hose cracks. I replaced all of the hoses and many of the symptoms (backfiring, dies instead of idling once warmed up) went away. Might not be your problem, but that plus replacing the gas are cheap fixes. (Actually, gas isn't that cheap anymore, is it?!)

If the tank was empty for a year and you filled it recently, there may be some contaminents in the system. Tanks don't like to be empty for long, it encourages stuff coming loose from the inside coating. Now your filter may be clogged. Check the gas coming out of the tank for dirt; there is also a filter in the bottom plug on the tank.
Sounds like your engine is running hotter because of a lean mixture, like it's getting not enough gas.
What is a C3?