Alright.....Here is the list of repairs so far:

main bearings
rod bearings
plugs and wires
fuel pump
oil pump
various gaskets

Now I cant keep the thing started. Its really shaky when I first start it up and then it keeps idleing out after that. Every time I come to a stop it kills. It seems to have gotten much worse since I replaced the fuel pump. Im assuming its something to do with the choke. Does that sound right??

 

Also, two questions. Where is the fuel filter located...cant find it? What gas mileage should I be getting?

Its an 87 with a 5.8L

Thanks!

 

The fuel filter is directly below the driver's side floorpan on the inside of the framerail. It should be silver with a black connector on both ends. If you do not have this filter(it will be directly in front of the frame mounted fuel pump), look towards the back for a black cartridge with a screw off bottom. There may be a filter in it. If you have both filters, replace the silver one and remove the screw in cartidge filter. Also, check the firing order and the plugs and wires. The firing order will be stamped in the intake manifold just behind the distributor. Should be 1-5-4-2-6-3-7-8. The wires will go counter-clockwise on the cap. Also check for vacuum leaks. A major vacuum leak will cause your concerns. If all this checks out, and still runs like crap, repost and you can get some more info possibly on the EEC system.

Robbie

 

I will get the filter taken care of. There really isnt anything wrong with it...I just figured I would change it for the hell of it. The plugs are fine. The fuel pump was bad, and the problem has started to get worse since I changed it. Plugs and vacuum lines are fine though (first thing I checked). Its hard to believe that I have has all these problems because the past owner didnt change a $16 pump. Oh well.

 

Just a thought, your truck also has a low pressure supply pump inside the gas tank. If you have dual tanks, one in each. It supplies fuel from the tank to the frame mounted pump. The frame pump cannot syphen fuel from the tanks on its own. To check the tank pumps, pull the rear line off the frame pump and have someone turn the key to on, the in tank pump should pump fuel for approx. two seconds.

Robbie

 

I would hook up a fuel pressure gauge to the service port on the fuel rails. Eliminate the fuel system. I think your barking down the wrong street. If you can drive your truck fine and it only dies when you coast I doubt its the fuel system.

I would check firing order for sure as someone else stated. Also check IAB valve, Check for vacume leaks. You had the intake off. Its easy to forget to put something back together or plug something back in. Check the PCV valve on the back of the intake.

Dave

 

Also,


Unless your motor isn't factory your have EFI. The choke is handled by the EEC-IV computer. Its not really a choke its more like a start up fuel table and another table it runs from during warm up untill it reaches operating temp and then goes into closed loop.

Dave

 

We pulled the carb off last night and we are going to rebuild it tonight. We checked for all of the other things before we narrowed it down to the carb. Ill let you know how it goes. Thanks!

David

 

Ok its carb. disregard the EFI ****.

 

We pulled the carb apart and it was a mess. Everything is back together now and running well. I guess I will have to see what happens next. I do have another question though. It is carberated.....but it has an EFI symbol on the front next to the grill. why?

 

Someone has changed it out before you. Only explanation. That is if it is really an 87 model truck and not just one someone put the 87 sheet metal onto.

Robbie

 

yea, last i checked, 87 was the first year of that front end, and it was fuel injected.

 

why would someone change efi for a carb? Doesnt make sense to me. It looks like everthing is stock.....honestly nothing would suprise me at this point....

 

maybe they had a truck with a 302, and they needed an engine for that truck. to stupid to make the conversion, so they just went the stupid way and put the carbed engine in it.

 

Actually, I own an 87 f150. It came with a 351w 5.4 4bbl holley 4180c carburetor stock from the factory. From what I understand, 87 was a transitional year where you could get them with EFI or carburetor. Find a chiltons manual for that year, it has both in it, and is very helpfull. (I have one)

It also has a mechanical fuel pump on the front right side of the engine.

I'm not sure if the carbureted version has the body mounted fuel filters, but I'm gonna check cause maybe that's whats wrong with mine!

My truck cuts out and boggs down when you give it very much gas pedal, and sometimes when you let off afterwards, it backfires. Sometime I can barely keep it at 55mph. I replaced the power valve in the carb thinking it was blown out, but no improvement.


My truck is also what they call a heavy half, which means it came stock with a lift kit and overloads on the leaf springs, upgraded shocks etc etc.

It also came with crappy one piece 4 wheel drive hubs that cost $165.00 each!

Clint (aka UH60L)