Hey everyone, just as the title says, i have a 89 f150 5.0l 2x4 that has 66,000 miles on it and it just got done sitting for 7 months, with about 1\2 a gallon of gas in it. I changed the shocks right away, then put seafoam in the gas tank, and drove it to fill up with gas. Ran horrible. I put gas treatment in the tank, and changed the fuel filter. Little to no difference. It's missing at idle, nearly dies when I first turn the a\c on, and knocks when I'm driving at lower rpms. The two other issues I have to deal with are that my fuel float suddenly stopped working (related??), and when I'm decelerating i hear a rumble that almost sounds like a rough spot in the road. Any one have any feedback on what these issues could be?


I'm going out to change the fuel pressure regulator now.

 

7 months isn't very long, and doesn't require shocks, fuel treatment, or fuel filter unless it had those problems before storage.

An oil & coolant change would be top of my list, followed by inspecting plugs, cap, rotor, wiring, & tires. Testing fuel pressure with a gauge would be a good move, too.

The rumble is probably a U-joint. Chock the tires, set the e-brake, shift to N, crawl under, and see how far the front of the d'shaft can spin BEFORE the back end moves.

 

Thanks for the advice, U Joint is on the list to do after the engine is running good again(tomorrow?), it did appear to be leaking from the rear U Joint, but the drive shaft was nice and tight. FPR didn't really change anything, I checked for Spark, Timing, IAC, MAP, everything is fine. I replaced the cap, rotor, wires, and plugs about 500 miles before it sat for the 7 months, just to be safe I did pull a plug out and checked it, looks fine. Shocks were due anyway, I know it's not related to this issue. Tires were low, at 15 psi but now back up to 40, wiring at a glance is fine but I'm tearing into everything tomorrow to make sure all is well (making sure I have a new battery for my multimeter lol). I can't help but think that front tank's float showing past full all the time is somehow related too(rear tank's float is fine). It's never had any problems before, and it's been in my family since it was new (grandfather babied it until 4 years ago). That's what I'll be checking in the wiring first thing tomorrow just to make sure all connections are strong to the fuel pump, selector switch, etc.

You wouldn't happen to have a link to the wiring diagram for everything would you? it's a 1989 5.0l EFI

 

When you changed the cap and rotor did you mess with the distributor at all?

If not I would check the upper to lower on the intake manifolds. I did a friends truck an 86 with EFI multi port back in 05 that had a rotted upper to lower plenum leak.

How it got that way I don’t know sense he never took it to a shop nor does he work on any thing past the 60's.

 

Thanks, I'll check the intake after the wiring, as far as the distributor, I did not do anything to it, other than timing of course.

 

If you changed the distributor timing, that could keep it from starting. The fuel level can't. Read these captions:

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The "complete" wiring diagram would take a book like this:

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I recommend finding the oldest Haynes manual you can get (red cover):

 

Timing was fine before it sat though, thats the thing, 7 months and 3 days ago this thing ran like a gem.

 

How much has it been ran since refueling? are you sure it only had a half gallon of old gas in it? 7 months that fuel was old for sure...

Edit outta currosity you did check the air filter right? i had one set that a mouse got in the air box and chewed up the filter and it clogged the intake hose

 

The gas that was in it was definately older than 7 months, and it actually ran out of gas before I filled it up. I started it, with about a half or so gallon in it of new gas (gas can). I let it run to temperature thinking it just had to relearn, etc. Then it ran out of gas, so I put a full can of gas into it and drove it to the station and filled it up. Last night I put some 91 octane in the rear tank thinking that it would help me determine if the front fuel pump is having any issues. Nope. rear tank runs just like the front tank, but cost me about 20 cent more a gallon lol. Since the truck came back to life, it's maybe had 100-200 miles put on it, and a lot of time idling lol, thanks again for all the help everyone, waiting on response from a guy on craigslist for an older red haynes, exactly like the picture. Air box is fine too, I checked it when I changed the FPR (airbox was in the way of me sitting on the engine to reach the FPR lol)

 

My guess is the the Fuel injectors are clogger/dirty

 

Cool, I figure that's easier and more likely than the electric problems, so I'm gonna be cleaning the injectors in about 30 min, just got home with new gaskets, o-rings, and an old haynes manual for $5, craigslist is my friend. I'll let everyone know how it turns out, i look at the bright side, I'm cleaning all this stuff and checking everything, so whenever i actually find whats wrong it'll run great haha.

 

Sigh, my luck. I got everything apart and everything looked pretty good, injectors were pretty dirty (attached pic), and upper intake bolts were barely hand tight. Cleaned all the injectors, replaced o-rings, all was well. On the way back together I tightened the front fuel rail bolt to 70 ft lbs, and snap! it broke off in the intake. Tomorrow I'm goin to buy a easy out and hope I can pull it out without issue...anyone have any advice on this?

Here's the pic of the injectors, one is clean of course, the other isn't the worst of the 8 either...think this could be some of the problem?

 

Yea id say that had something to do with the running rough, good luck with the bolt

 

Those are just the pintle caps, and the deposits on them are from the PCV & EGR systems - not the fuel. It's the other end that would clog & create problems. The bottom end is designed to work even with those deposits.

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For the bolt: If there's anything sticking up above the intake, try to grab it with pliers & back it out BEFORE anything else. If that doesn't work, try to grind the broken end flat before center-punching & drilling it with a left-hand bit. Use penetrating oil so it can spin out easily. Put a long bolt into the other hole so you can compare the angle of your drill to it & stay in-line.

 

I did clean both ends of the injectors, but I couldn't see inside the other end to see how dirty it is. Given how dirty the end I could see was, I would think it was pretty dirty, but if not, this is yet another thing that can go into the "Things that aren't the problem" category.