84 Ramcharger 5.2 2 Barrel

[[email protected]]

Trying to help out a friend here. His old truck will run good at start up and after it heats up it starts to back fire and quits running. After it cools off will run again to that coolant temp and quit.

Has a ported vacuum switch that has been ruled out as we jumped the lines when engine was warm and problem still exists

Says it has been using a lot of gas. Had back fire and blew out the muffler with pieces of his catalytic converter.

I saw a part named Ignition Advance Control Switch that was listed seperate from the ported vacuum switch. Advance switch sounds like it
might be causing this just by name alone.

Truck is old but still has parts available. Any help on this system would be of great help at this point. Today I wrote off as mysery loves company.
Tommorrow I would like to be more prepared.

Thanks and Good luck

[[email protected]]

Originally Posted by [email protected]

Trying to help out a friend here. His old truck will run good at start up and after it heats up it starts to back fire and quits running. After it cools off will run again to that coolant temp and quit.

Has a ported vacuum switch that has been ruled out as we jumped the lines when engine was warm and problem still exists

Says it has been using a lot of gas. Had back fire and blew out the muffler with pieces of his catalytic converter.

I saw a part named Ignition Advance Control Switch that was listed seperate from the ported vacuum switch. Advance switch sounds like it
might be causing this just by name alone.

Truck is old but still has parts available. Any help on this system would be of great help at this point. Today I wrote off as mysery loves company.
Tommorrow I would like to be more prepared.

Thanks and Good luck

i posted this in the Magnum Area by mistake.

Actual name of switch i/m intereseted in is the Ignition spark advance switch

Thanks

[rhandwor]

Unbolt the catalic converter at the front flange. If you break a stud drill it out and use a new bolt and nut. If it still back fires use an ohm meter and ohm all plug wires. They will cause a back fire. Take a compression test a bad lobe on a cam or bad spring will cause a back fire.
To check for a stretched timing chain pull the distributor cap rotate the engine by hand past tdc about 60 degrees. Then turn back to tdc use white out and mark the tip of the rotor and the dist. base. Have a friend watch the rotor as you turn the motor by hand stop as soon as he says it started to move. If it took over 20 or 30 degrees you need a new timing chain.
I think you have some type of timing problem. A bad vacuum advance or bad temp. sensor if computer controlled can also cause problems. With the age of this truck I think it is a mechanical problem.

[jsweeter]

I would get rid of the truck. I had an 87 ramcharger and had the same problem. Messed with it for 2 yrs. and never figured it out. Sold it and a week later the guy came back around sayin the engine blew up.

Get rid of it or put a new engine in it.

[rhandwor]

This is probably good advise. Its amazing what a rebuilt short block and a valve job will do for engine performance.