[Guest]

my 78CJ5 has a 304 engine and everything is pretty much stock except for a performer manifold with EGR and an edelbrock carb.
when it is cold there is a power loss but the engine feels smooth. when it gets warmed up it gradually starts missing/cutting out under 1700RPM. when it gets up to full operating temp, it cuts out pretty bad. this problem has slowly become worse after time. it first started about three weeks ago.
since then this is what ive done:
changed spark plug wires
changed spark plugs
changed distributor out for a rebuilt one
changed cap
changed cap
changed fuel filter
insulated the aluminum line between the fuel pump and the filter
swapped to a different coil to check
swapped to a different ignition to check
swapped to a different carb to check
ignition timing has been checked and played with, with no results
i then took it to a place to have it put on a scope. they told me that when i took it in, three cylinders were low on compression. they then deleted my vaccuum delay for the EGR because it was bad and leaking. a replacement could not be found. so the EGR was mounted directly on the manifold. they ran the test again. the compression levels were all at 125-130 now. i couldnt feel a difference when i picked it up it still runs like crap. i called them and they said their scope reads that compression is good, timing chain is good(not excessive play), the valves are good, head gasket is good. also it took them two days just to find the EGR problem.
anyways if anyone has any ideas or comments, please post them. any help is appreciated
Joey

 

[Guest]

my '77 304 was doing the same thing, so I rebuilt it. Mine was completly stock, and now has the edelbrock (no-egr) and performer carb... I had a burned valve on the #2 cyl, but I don't think that was causing it... I was also going through fuel pumps rather quickly, you might want to check that and see how dirty your fuel system is...

Florida Mud CJ-5
'77 RB304, t-150 D20 4" 35" swampers

 

[Guest]

the mechanic i took it to who put it on a scope said that the scope would have read any bad valves. he assures me that the valves are good. also when i swapped the carbs i visually inspected how the fuel pump was flowing through the hose that connects to the carb. it seemed solid and strong. but thats as far as ive gone as far as the fuel system goes. i was checking to make sure there was no air in there and the fuel pump was fowing strong.
thanks for the info
Joey