I have a 86 F150 300 l6 and it wask skipping when idling and smoking horribly. I tried to narrow down the skip by removing one spark plug wire at a time. No matter which wire I umplugged there was no change in idle. This tells me that the skip is jumping around? I think. The day after that I went to start it and now it is running on one or two cylinders. Please help anyinfo would be appreciated. I've changed the cap plugs and wires.

 

[updated:LAST EDITED ON 17-Jan-02 AT 01:32 PM (EST)]It sounds like ignition problems, It could be wiring to the coil that is interuping the current flow or signal to it. It could be the TFI module on the base of the distributor or your pick-up(Hall sensor) in the dist.which would affect the fuel system(typical with these trucks) I would begin by checking all the conections on ignition system, also check all vacum hoses for leaks, a leak can cause the computer to go wakky and make it seam like an electrical problem or fuel problem also pull a plug and see if its black with carbon or white this could tell you if it is not burinng the fuel or its not getting enough fuel. then check for codes(if possible) then start testing components The Haynes manual for f-trucks is real good and has all the codes and test proceedures in it.There could be a number of things so systematical illiminate components(this procedure has never failed me!) Good Luck

400m

 

[updated:LAST EDITED ON 17-Jan-02 AT 01:44 PM (EST)]Thanks for the info. Don't I need a tool or machine to pull the codes. I've never done that so I was wondering how I would go about doing that? I checked for vaccum leaks all around the carb. nothing. Thanks for your help. I replaced the plugs and the old ones were competely black with carbon.

 

[updated:LAST EDITED ON 24-Jan-02 AT 12:37 PM (EST)]After checking your plugs and distributor, check your PCV valve and hoses, are they plugged? What condition are the air filter and oil breather filter? How about the fuel filter? These parts are relatively inexpensive to replace (and should be replaced regularly anyway), so if in doubt, replace them. The problem you're experiencing may be a combination of several things.

How old are your coil and plug wires? Usually you will benefit by replacing these anyway. The Ford stock coil and wires aren't so great to start with. Easy to replace, just a little more money. I usually get ones that are rated for higher performance (may as well save some fuel!) :P

You mentioned that you have a carb? Then you won't need a code checker... If you do have an EFI, you can get a code checker that is fairly inexpensive, I think Equus has one that costs around $20. You can get them in the automotive dept. at Wal-Mart. Definitely worth the money.

You can also get a relatively cheap tool that will check the condition of your spark plug wires. It works on induction, just hold the metal loop to the wire to detect the presence of a spark. I think mine costed me about $10.

A side note: After doing a larger-scale tuneup on an EFI engine, I like to reset the ECU by disconnecting the battery for a few minutes, so the computer can "re-learn" the engine characeristics from scratch. Also, I like to run some Duralube fuel treatment through the fuel system as well... Just a personal preference.

Besta luck,
Markus

 

"smoking horribly"---Black smoke or blue smoke? It sounds to me like it is fuel related, some things to look for are your idle mixture settings, sticking choke, leaking float...oh, check and make sure that your air cleaner is not clogged...malfunctioning EGR