I have a 1987 F150 4WD 300 I-6cyl. It has a rough idle and rough acceleration as well. I have done a compression check which is good. I have replaced the plugs and wires. While the truck is running you can remove plug wire #1 and the truck idle does not change. The plug wire is getting plenty of spark when grounded to the engine block. The only thing that I can think of is the fuel injector on #1 cyl. Any thoughts? Like I said the compresion is good and the cylinder is getting plenty of spark. A friend of mine had a Toyota that did the same thing. He removed the fule injector, cleaned it and it fixed his problem. Any help would be greatly appreciated.

 

yea id be suspicious of that fuel injector. Clean or replace it and see what happens.

 

If it worked for your friend it should work for you.Just remember to lube the o-rings before re-assembling.
:santa:

 

OK, I replaced the injector but as with my luck no help. If you rev the engine it misses, but say you rev the engine up to 3000 rpm and hold it the engine runs smooth. Any help would be greatly appreciated.....

 

I would now start with the basics; new fuel filter,clean the throttle body,check all vacuum lines......My money is on the throttle body.If its never been cleaned,its probly very carboned up.

 

New plug bad ? Not all new ones are good. What did you do to the engine BEFORE it started running poorly? You might go back to your last step.

Regards,
Curt