454 misses/backfires....made worse!

[EXFFPM]

I carefully replaced the fuel filter, distributor cap, rotor, plugs and wires on my '93 Bounder 454/P30 hoping to eliminate the misfiring/backfiring. Upon restarting, my ampmeter/gauge did not register and the engine ran poorly and backfired when I stepped on the throttle. I assumed that I had crossed a plug wire and triple checked finding all well. Restarted engine and it ran fine, ampmeter read normal....but engine would load up and die after approx. 2-3 mins. Started engine again and ran rough with heavy black smoke from exhaust and would not idle. Engine readily restarted with one of the three results following repeated attempts. Chassis battery very low upon initial start, had to use aux. start button (coach batteries). Am at a loss.... any suggestions?

[EXFFPM]

I carefully replaced the fuel filter, distributor cap, rotor, plugs and wires on my '93 Bounder 454/P30 hoping to eliminate the misfiring/backfiring. Upon restarting, my ampmeter/gauge did not register and the engine ran poorly and backfired when I stepped on the throttle. I assumed that I had crossed a plug wire and triple checked finding all well. Restarted engine and it ran fine, ampmeter read normal....but engine would load up and die after approx. 2-3 mins. Started engine again and ran rough with heavy black smoke from exhaust and would not idle. Engine readily restarted with one of the three results following repeated attempts. Chassis battery very low upon initial start, had to use aux. start button (coach batteries). Am at a loss.... any suggestions?

[Gary RVRoamer]

Distributor cap perhaps rotated 180 degrees? That would put the timing off severely. I don't know if the 454 distributor can be installed that way or not, but check it out.

If it has a distributor cap and rotor (I thought they were all solid state by 1993), does it also have points and a condensor? Your problem sounds like ignition timing.

[Fred B.]

Not familiar with the newer engines, but black smoke indicates too much fuel.

[Toby]

EXFFPM
Make sure all of your vacuum hoses are connected. A lose one will result in rough running and back firing. s/Toby

[Gary RVRoamer]

Vacuum hose disconnected - good call, Toby. That's a likely cause.

[EXFFPM]

Good call on the vacuum hose....so far. Waiting to see if lack of sufficient voltage from weak alternator/drained battery resulted in computer malfunction? Have kept battery charged since then and running perfect. Replaced the alternator since first post but charge voltage not being read at battery or on stock in-dash meter. Can't seem to win.