So I just did a tune up..new plugs, wires, MSD distributor cap, oil, oil filter, fuel filter. It cranked up just fine and ran good for a while, then it started spitting and sputtering, died on me..it cranked right back up so I drove it home, it spit and sputtered again for a while, then kicked back into gear like nothing was wrong. It has fuel, fresh fuel and like I said, a new fuel filter. I changed out the air filter with a ram intake, so it's not an old air filter. the timing is right on it because it's sucking up air like a champ and has great throttle response...it was top dead center when I did the tune up. when I tried to take it out for a drive today it didn't want to run at all, every time I hit the gas it hesitates and then tries kick back up but hesitates again. The only thing I can think of is it's dumping too much fuel, when I hit the release on the fuel rail it shoots out in a big, strong stream. the spark plugs seem to have a lot of fuel on them, is there anyway to adjust the amount of fuel that gets dumped into it? I don't know, any suggestions as to what it might be, I'm at a loss for options here. Thanks guys..and gals

 

if it's doing it when hot it could be the coil. had the same thing happen to my '89 f150. ran good cold then got rough at operating temp, particularly when accelerating. might also be the fuel pressure regulator maybe. been years since I owned a blue oval with EFI(though that will change wensday if everything works out)

 

where is the fuel pressure regulator..it does it when it's cold or hot. does it all the time. I tried looking for it online but I can't seem to get a picture of it.

 

I think it's near the fuel rail on the driver's side. I don't think they're very expensive but it's been maybe 7 years since I pulled mine and 3 or 4 since I sold the truck. I think it's held on with 3 screws and has a small vacuum line with a 90 degree elbow on it.

however between '87 and '89 or so they had 2 different fuel systems for trucks with dual tanks. mine had the funky old system with 1 low pressure pump in each tank feeding the high pressure main pump so if you have the newer setup the pressure regulator might be totally different, dunno.

 

I have the one with dual tanks, the one main tank doesn't work, the plug in sending unit is fried..something I have to replace. I'm using the reserve tank and it ran fine. advance auto has one for about 22 bucks, think I'll go that route and hope it works out. if not, I'm at a loss I may have to break down and take it to a mechanic. I think that it has got to be it, I think that it's pushing too much fuel to the injectors causing it to run rough. I'll try the new regulator and see what happens..I'll let u know

 

they had two different systems for trucks WITH DUAL TANKS. one system has a main high pressure pump being fed by two low pressure pumps, one for each tank. the other just had a main high pressure pump for each tank.

 

Problem sounds like timing...If you adjusted the timing did you first disconnect the spout circuit>>>>CLICK HERE> Ford Fuel Injection » Setting the timing ...also I think that motor is 10 BTDC

 

yes i was about to say the same on my 86 f-150 when i did my timing without unplugging the spout circuit it acted the same but eventually wouldnt run at all. it could also be an injector problem a short in your fusible link. Add some heet to your gas if it is injectors that should help clear it out or any other octane product that you would like i would suggest lucas fuel injector cleaner.

 

Like slip ford said , if you have the base timing set at TDC thats a problem , remove the spout and set the base timing at 10 deg BTDC...

 

No what is the spout circuit? Where is it located? I'll try that in addition to replacing the fuel pressure regulator.

 

Your supposed to click on the link that I posted

 

someone mentioned HEAT and that reminded me of a time when I filled both tanks at a crappy gas station and the gas had water in it. I dumped some HEAT in and that solved the issue. I knew a guy that thought he had water in his fuel and he used HEAT and that cleared it up for a bit but next fill up it stated it again. turned out to be a coolant leak and the steam was getting pulled into the intake. wouldn't hurt to spend the few bucks and get some fuel system cleaner or HEAT and while you're at it you should get that other fuel tank working, maybe the other pump is on it's last leg. in any case I've learned the hard way not to let things slide. even if the problem won't get any worse something always rears it head at the worst possible time and suddenly that minor issue you've been putting off manages to be a contributing factor to a larger crisis.

 

Sorry I'm on my iPhone. Didn't see it

 

"the timing is right on it because it's sucking up air like a champ and has great throttle response...it was top dead center when I did the tune up"

Huh?? Please elaborate.

 

we made sure the crank shaft was lined up with the paint lines that came on it from the factory, the motor was top dead center. if the timing was off, from what I was told, when engine goes to suck in air it will be either very week or suck in then blow out.