1972 Kayot M/H Fuel pressure

[nickscarcare]

I am wondering if anyone knows what fuel pressure spec should be for this motorhome. It has a Chry engine, I think a 318. It has problems with power at 55 mph and up hills, has a slight misfire, someone installed a aftermarket electric fuel pump and I have about 7 psi out of it. It is backfiring at times. Any help would be appreciated. Got to try to find block numbers to identify the engine.

[steven kiser]

If you apply the brakes and torque it does it skip? I've had issues with the floats being out of adjustment and an air gap forming in the accelerator sleeve causing a lean pop. If this is a four barrel carb with a metal top and bottom and a black plastic (bakealite) center they had a habit od twisting and under slight acceleration there would be no acceleration squirt.

They also had issues with the egr valve. The amplifier would mess up and trigger the egr at slow acceleration. We would yank them and Chrystler offered a block off plate. Does this have the Lean Burn system in it? If it had the module with the advance diaphragm attached to the air filter housing it is. The modules would scatter the advance signal during acceleration and we would advance the timing and plug off the vac lead to the module to compensate for it.

Chrystler had an issue with the accelerator plungers shrinking in un leaded fuel. I remember having the cups and upper gaskets in stock. If it is the 4bbl i described there is a pretty good chance that if you remover the top of it you'll be able to see the twist in it and the chances are slim it will seal when it's reassembled. Not sure but i believe holly offered a bolt on replacement.

[nickscarcare]

This is a 2 barrel carb. It has no egr valve. This guy had 4 local shops tell him they could not work on it because it was to old and didn't have a computer?!?!? What kind of shop are they? I was just trying to locate a fuel pressure spec. If the 7 psi is enough or if it should have more like 13?

[liljoe]

7 should plenty, most pumps ( mech) put out 5-7, so 7 should have you covered.

[liljoe]

Think I would look at t-chain and see how loose it is, Seen simmular on these engines....

[steven kiser]

i would look into the carb throat while slowly pushing the throttle and see if there is a solid stream of fuel. Obviously not running. The stream should be constant. I'm thinking it's just going to dribble under slow acceleration