[Overtipper]

Hey there!

Here's a question for you - If you get a chance, read my "newbie" post, but here's the gist of the thing: My Dad's F150 (XL, 4x4, 4.9L, "Y") has a "skip" when it's idling. It does it all the time when idling, but randomly, not like every 3 seconds, or 5 seconds. The engine shakes slightly when it does this. I have a new distributor, cap, rotor, wires, plugs, and ignition module. There is a light knock also, which I believe is a pin or a lifter. No problems under power, but if I am sitting at a light (grrr!, lights!) it will idle, and then "skip" or "hesitate". Doesn't quit, but that skip is REALLY annoying. There is a check engine code, "vacuum leak".

I don't know if this has anything to do with it, but twice when it was wet out... it just quit. I had enough momentum to get it into a parking lot, but it wouldn't restart for approximately 3 hours. Once it sat that long, it starts right up.

Any ideas? I'm stuck... not knowing if one has to do with the other, and not too keen on throwing parts at it on my budget.

Thanks!!! Overtipper

 

[Mr Mac]

I remember my three F-150s that had the 4.9 I6 engines (1983, 1989 and a 1992) and every one of them had a slight skip at idle and I was assured by the best mechanic I knew at that time (my dad who was a professional mechanic for better than 50 years) that it was a normal thing for an inline engine to do so, I never worried about it. Still, you also get a vacuum leak warning so it might be time to locate and change out all your vacuum lines. It isn't a difficult or expensive job but getting all the right kinds of lines in the right places can be tough without a road map. I'll see if I have one. What year is your truck?

As to your other issue, it sure sounds like you're getting some water in something that doesn't need or want it! Normally I'd suggest checking the distributor cap but you said it was new so it might be that there is a sensor plug that is allowing water into it causing a short that the PCM reads as an engine issue. If it happens again, disconnect the negative battery lead for about 30 seconds and see if it will start right up. If so, find out what's exposed and fix it, if not, then...well, I'll get back with you then!

Mac

 

[Overtipper]

Hey again!

The truck is a 1995. If you have some kind of diagram, that would be aserious help.. all I have is that darn sticker on the inside of the hood to guide me... and it's in, well, pretty bad shape.

As far as the water problem, I was thinking that the water is running down the firewall to that big electrical plug (vertical on the firewall, drivers side). I started wrapping wires, but it's a slow process with my work schedule, and the fact that it's still in the 20's and 30's here.

I appreciate the help - I would hate to get rid of the truck, not only cuz it was my Dad's.... but I like the darn thing!

Overtipper

 

[Mr Mac]

I don't know if this is a real help but it's what I have...

 

[Overtipper]

Hey again!

Thanks for the info. I actually have a day off for a change, so I'm gonna spend a little time trying to figure out where that leak is. I'll let you know what happens!

Overtipper

 

[Mr Mac]

Thanks for the update!

Mac