weird miss and loss of power

[nosxih]

My 91 RRC seems to run really ruff when it warms up, most notably when in stop and go traffic. All is well when suddenly it loses power, it will coast fine but struggles under any load whatsoever. I also notice a muffled noise right in front of the driver under the bonnet(left hand drive) sounds like you're thumping an empty coffee can. Noise is reoccuring. Often when the road turns flat or downhill this situation corrects and she runs fine. Sometimes it is so bad that I creep along no faster than 10-15 mph.It has new fuel filter, fuel pump, o2 sensors,alternator. Any ideas?

[singingcamel]

next things to address is the electrical issues,if it has not been tuned up i would do so, tune it up ,rotor cap, plugs and plug wires.
also it may be plugged cats as well.that may your noise you describe

[CJH]

Check:

• Plug wires carefully, original ones are crappy, suggest replacing with Magnecore wires.
• Distributor cap, clean inside carefully & look for cracks or carbon tracks. Same for the rotor. Use caution when removing rotor, guts of distributor can pull out when removing rotor. If it is really stuck, break it to remove, then light coat of dilectric grease on new one.
• Coil for good grounding, clean all bolts, wires to ensure a good ground.
• Fuel injector connectors. If moisture gets in connector, terminals can corrode.
• Watch your tachometer when it's sputtering, a bad alternator will send alternating current to the engine computer & piss it off. A bouncing tach is a good indicator of an alternator issue. Or hook up a voltmeter set to AC & watch it under load. Less than 1.0 volt AC is acceptable (ripple voltage)
• A broken catalytic convertor as mentioned will cause all sorts of issues. Give it a smack & listen for rattling ceramic matrix material. Can sound like marbles in a can, or exactly like a rod knock (mine)
• Low fuel pressure, shouldn't be an issue with the new parts.

Good luck, hope you find it quickly!