Lean Burn Question(s)....

[moparnutcase]

I know, get rid of it,lol. That may happen in the future but for now would like to make it right. Try to keep this as short as possible. This is for my '77 'Doba,12,400 original miles.
Fuel tank redone,sending unit rebuilt,new fuel filter(original one still on car when purchased),carb rebuilt(note stating system should be cleaned because of the debris found in carb),blew out fuel line. Lean burn computer has "remanufactured" on bottom(so replaced at some point,probably when car was fairly new.) Except for plugs, ignition system all original.
My issue.....when car fully warmed up in gear, if you do not feather the gas pedal to start rolling it will die. Almost like it has a miss til you get going(rough feeling). Has a slight stutter on choke but stays running if you hit the pedal. If you hit the pedal too hard and it quits it is a crap shoot if it will re-start, most of the time have to spray some starting fluid. If you just shut the car off by key and not making it quit with the gas pedal it will fire right back up.
No expert here so looking for suggestions. My thoughts lean(no pun intended)to the carb. Accelerator pump not working properly? Float not adjusted properly? If anyone can point me in the right direction would be much appreciated, thanks!

 

[493 Mike]

Just make sure all settings are "factory". The acc. pump is the same as any TQ on nonlean burn engine as far as function. These cars, when new were not very impressive. I was still working in a Dodge dealership back then.
Mike

 

[PurpleBeeper]

It does "sound" like an accelerator pump issue. Just take off the air cleaner with the engine off, look down the throat of the carburetor, & pull back the accelerator lever. You should see a nice long 2-3 second, powerful stream of fuel in both front barrels from the "squirters"...no sputtering, no weak dribble, etc.

And by the way, that is a beautiful Cordoba. I had a '77 400 4bbl lean burn Cordoba and it was very comfortable with lots of options. I put a '71 440 in it with a 292/509 cam and got it up to 150+ mph (based on the certified police speedometer I had installed)...it was bouncing off the 150mph peg.

 

[rlem1977]

As others have offered, it does sound like a carb issue. It may also be a combination of carb and timing advance issue. The computer controls timing advance upon acceleration. There is a coolant sensor that signals the computer to retard the timing when cold, advance it when hot. I think there is a engine load sensor that signals the computer to adjust timing as needed. Any of these along with a a potential carb weakness could be your culprit. Hope you get it going.

 

[moparnutcase]

The car is drive-able, drove it like that last year. Just have to be gentle on the pedal when starting out. Of course I would rather have it working properly. Need to wait for nicer weather and see what is up. Thanks!

 

[mopar 3 B]

The vacuum advance can on the drivers side of the computer can is working and there are no vacuum leaks? Stick a vacuum pump on the advance and see if the timing changes. You should notice an increase in rpms with out throttle movement.
Your Doba also has a aux vacuum can is it still intact?

 

[Billccm]

The two large connectors to the lean burn printed circuit board are susceptible to fractured solder joints. Maybe your remanufactured device addressed this issue, but if not it's something to suspect.
Get a can of deoxit and cotton pipe cleaners. Spray the connections to the lean burn and all sensors. Shine the contacts with the pipe cleaners.
Chrysler was once again way ahead of it's time with lean burn as all cars today have spark timing in the ecu. Unfortunately poor solder workmanship and the location of the computer itself caused many headaches.

 

[moparnutcase]

The vacuum advance can on the drivers side of the computer can is working and there are no vacuum leaks?

Will have to check that. As far as I can tell everything looks good with all the hoses. Not saying that there is not a leak but everything looks to be in good shape. Not that it pertains to the issue but the car still has its original belts and coolant hoses as well. Nothing is dry rotted.

 

[moparnutcase]

The two large connectors to the lean burn printed circuit board are susceptible to fractured solder joints. Maybe your remanufactured device addressed this issue, but if not it's something to suspect.
Get a can of deoxit and cotton pipe cleaners. Spray the connections to the lean burn and all sensors. Shine the contacts with the pipe cleaners.

Never can be sure about the computor,lol. Except for the initial stumble, car seems to run pretty good. I did a 420 mile round trip out to Carlisle last summer with the A/C on both ways and knocked down 16 mpg. Today I tried manually moving the accelerator cable and saw no fuel at all squirting into the carb. So, maybe the accelerator pump could be the culprit......

 

[mopar 3 B]

Never can be sure about the computor,lol. Except for the initial stumble, car seems to run pretty good. I did a 420 mile round trip out to Carlisle last summer with the A/C on both ways and knocked down 16 mpg. Today I tried manually moving the accelerator cable and saw no fuel at all squirting into the carb. So, maybe the accelerator pump could be the culprit......

Dad would have been tickled to death if his had gotten that. Can remember him complaining about the 11 or 12 mpg from the 400.

 

[moparnutcase]

Dad would have been tickled to death if his had gotten that. Can remember him complaining about the 11 or 12 mpg from the 400.

It does have 2.71 gears in it. And I kept the speed at 60 for the most part with cruise control for the highway portions of the trip.

 

[mopar 3 B]

Sounds like same standard equipment. Dad was in his late 60s by them but was known to have a heavy foot.
The car could not have been much over 5 years old at the time.

 

[moparnutcase]

Being my car is all original with just over 12,000 miles, I like to be "easy" on it, especially since it has almost all the original components it left the factory with.