Misfire and chattering relay

[scrofts007]

My 4.0l 2000 explorer has ben misfiring (particularly when cold) for a few weeks. I have changed spark plugs and leads, but it continues. Over the last few days there has been a distinct "chattering" around the steering column area that corresponds with the misfire. Once it's warm it's mostly fine, but can still sometimes continue. I thought is was possibly a fuel relay, but It has it has been converted to LPG and the misfire is worse on LPG than petrol - do they share the same fuel pump - I would have expected it to be different.
If they share the same relay - could it be this (Does the relay sit uner the steering column?)

Also whilst changing the plug leads I spotted a broken very small bore pipe (Probably only 2mm internal dia), but couldn't see where it attached to - it wa on the opposite side to the battery near the water and radiator top up area - is this important and where should it attach?

Thanks in advance for any replies.

 

[scrofts007]

OK I've just spent £300 on having the Mass Airflow sensor etc replaced and well as alterations to the idle screw, but the misfire is still there (It only happens when engine is warm, and is at low revs - about 1500 rpm - when asking the engine to work a bit - eg small hill. It coughs and judders, but if I give it more gas, it changes down, the revs rise and it's fine)

I've found a relay under the steering column, but don't know if it's anything to do with the fuel system (Could be a flasher unit for all I know!) - can anyone advise?

Thanks
Stuart!

 

[cfd911]

hi, i do believe it s very possible to have that chattering relay, one of our ford diesel's had a noise like a chirping noise under the steering colom that would occur at idle and while driving, the dealer said it could possibly be a relay contacts bouncing inside the relay and or the relay going bad.

now i know where talking about 2 totally different vehicles but i thought maybe this might give you alittle help.
about your warm misfire while under load it could be alot of things, but i would think it s either fuel or spark, when the truck is cold it get a richer mixture of air/fuel, but when warm it leans out and the computer takes over to give the best air/fuel ratio,
and if it bucks under mid throttle or load maybe it could be coil pack????????
it sounds like your on the right track, or at least thinking about it.

i m alittle stumped too that s why i m looking to get a dealer manual.
good luck.

 

[cfd911]

look at threads noticed, possible intake manifold leak or vacuum leak, maybe fuel pump relay just some ideas