I have a 89 F250 with less then 40,000 miles on a US Motors 5.8L. I went outside to start it up without touching the gas pedal and it fired right up like usual. It ran for a second and died which also happens sometimes. I went to restart (after everything had stopped moving) and the starter ran and ran and ran with no fire. What the hell? Finally it popped and spuddered and died again. I got in it and put the pedal to the floor and turned it over again. After turning over for a while it fired, revved, and as I ran it down I noticed it was running rough, missing badly, and wouldn't idle. I checked the rotor and it looked fine inside. I hope it is a spark plug. What's wrong with my truck?

 

More info is needed:

-Stupid Question, don't kill me for asking, got gas in it?

-Got the smell of gas anywhere? How much PSI is your system holding?

-Check the spark?

-Any recent fixes/problems we should know about?

-Sounds more like a fuel problem to me, fuel pumps working ok?

-Check your Fuel Pressure Regulator, does it hold a vacuum?

 

Its not a gas problem, the truck runs with my foot in the throttle. When the rpms drop is when you can tell something is wrong with missfires, blue smoke, vibration. Sounds like its not running on all 8. I hope it is just a spark plug or wire but could it be a valve or broken connecting rod?

 

Sounds like my truck. I let the oil level get down to 2 or 3 quarts. A fter I changed the oil the truck ran real bad, stalled, shifted bad would not idle smooth.Yesterday I cleaned the cap and roter, but most effective was I cleaned the throttel body with a whole can of T.B.cleaner. I also ran a can of Seafoam into the brake vacuume line. Today it ran as good as it ever has. Look into the throttel body if it's dirty clean it . It can't hurt.

 

actually, it sounds exactly like a gas problem, sounds, to me, like something a FPR would do.
Do you sometimes have to start it by putting the gas pedal all the way to the floor?
Honestly, the blue smoke part is what concerns me, sounds like its running way rich.
But there is the possibility of it being the ignition too, I would like to know why you ruled out the gas issues right away? Could you clue us in on why?

-Rad

 

I knew it wasn't a fuel problem because the truck would actually run for long periods of time, just real rough. I just went outside to make sure it was doing the same thing to describe it better and it magically fixed itself! It ran like crap for a minute and then cleared up back to its old flowmaster raspy rumble! I love Fords!

 

A Fuel Pressure Regulator, as I have seen does this. Mostly they run, they usually start hard, but do start, seem to run and will run for a long time, like crap, but will do it, with increased fuel consumption.
Does it do this when it's cold? Usually they start right away after sitting overnight, since the fuel has had a chance to trickle out of the main line and the fuel inside the vacuum line has evaporated out.
Usually they're tougher to start when they're hot and only sat in a parking lot, off, for about five minutes.
The blue smoke, is usually a clue that they need to be checked.
Now, with said, I could be wrong, but I've seen this same scenario many times.

If you want, it's a very simple check, all you need to do is pull the one single, red vacuum line off the manifold, which leads to the FPR, and apply vacuum to it, sometimes it's apparent that its saturated with fuel, that's BAD, time for a new one.

Sometimes, you have to actually apply a vacuum to them...either by a vacuum pump or you could do it the "simple" way...suck the heck out of with your mouth and hope the FPR is ok, otherwise you often get a mouth full of gas. Either way, if it holds a vacuum for 5 seconds (guesitmate) or more, it should be ok. It would make me feel better knowing this was checked, but thats just my $.02.

Hope this helps, otherwise, it sounds like an ignition tune-up should do the trick.

 

Thanks for the two cents, I'll have to check the FPR and definitely perform a tune up if this problem persists.

 

Another thing that could possibly be wrong (if you have the EEC IV computer system) is the actual PCM module on the distributor.

I had this problem when i tried to set the initial timing on my 351W, and i slipped on the wrench and hit the module. It stalled and sputtered, then it died. Then it seemed like it just wanted to start at random when it wanted to. It would crank crank crank, and then i would put it to the floor and it would come alive, then revv really high, and sputter on its way back down then die. Didn't feel like it was running on all 8 and felt like the timing was so far off that the engine was running against itself.

Had to take the distributor out and replace that PCM module, was only $30 at Autozone, with a lifetime warranty. If you do get it, make sure you get the dielectric grease that helps in cooling it. And after you get the mounting bolts out, it slides down before it comes off as there are 3 prongs that go up into the distributor housing. Good luck, let us know what happens!

 

if it starts, pull the codes from the computer. sometimes the check engine light wont come on even with a problem it should register.

 

You do not need your engine running to check your codes. Run a Key On Engine Off (KOEO) test and post your codes here. Your computer has stored any codes.

 

if you dont know how, it tells you how to do it on fordfuelinjection.com let us know if everything gets fixed and what was wrong

 

Who make's the Us Motor's ?? I'll be looking soon for 351 Windsor but Carb. It's 87Ho