I have a 84 eldo conv. 4100 engine it bogs out even in park wont rev up and some times backfires. then out of the blue it will run perfect till next time I go to drive it then same thing. we checked converter, had dist. out, new gear on it, wires and plug check out. was told maybe a weak dist, should try a rebuilt. any thoughts? appreciate all sugestions.
thanks, DNE

What trouble codes are showing? R U working off the FSM?

only code that shows is Ithink 52 witch is just that its been cleared i believe
DNE

E52 means the power was disconnected....battery unhooked. When the power is lost to the computer, many bad things can happen. All 'history' is lost and the computer system reverts to the default program of the PROM. That program is only used when the engine/all its sensors are brand-new. The 'history' is what the computer learned in order to tweak the default program in order to make the engine system work to the best of its ability...given time/age. If the battery was recently disconnected, possibly given enough time, the memory will rebuild and the ECM can compensate. FSM? If not, you really should obtain this valuable tool. Many available on ebay. This is a must-have for the Cadillac owner who does his own work.

You need to verify fuel pressure is between 8 and 12 lb. all the time. A partially clogged filter screen (sock) in the fuel tank can cause intermittant problems and restrict fuel. This filter is 25 years old!! My 85,000 mile car quit 2 weeks ago out of the blue at 75 MPH. This in tank filter was so restricted, the electric fuel pump gave up. The pump was 49.95 and the sock was 11.00. at an AUTO ZONE. 2 jack stands and a few wrenches and I had the pump replaced in 2 hours. The 3 fuel hoses are easy to get to at the front of the tank. Starts quicker, and runs great. Mine would bog and hesitate at times leaving a stop sign and crank over 6 or 8 revs before starting cold for about a month before the pump quit.

I agree with Carnut, fuel pressure should be checked first. Vacuum lines or timing chain will cause intermittant problems as well.