Hi,

My 1998 F150, 4.6L auto 4wd does not move much but I always start it once a week. Right now it has about 47,000 miles on the odometer. The trip meter reads 333 miles and the fuel level reads 1/4 tank. This week it started and ran for a few minutes then died.

I have checked the shrader valve and get a little fuel there. The fuel inertia switch has been checked as well. It is so windy out that I cannot tell if the fuel pump is spinning up. The fuel pump fuse is good. The fuel pump relay clicks pretty loudly and the check engine soon light blinks. I switched that relay with a similar relay and found the same clicking problem but at least the truck would start (but it dies after a few minutes). I have put the relays back where they belong.

My fault checker shows nada- it comes up with a display of 8888.

So, something is screwy. Would anyone have a suggestion of something to check?

 

You should get a LOT of fuel at the shraeder valve, but it sounds like you're not.

That means you have a fuel delivery problem. Possibilities include fuel filter, fuel pump, and the power to the fuel pump.

Have no idea what you're using as a "fault checker"....

Steve

 

could be fuel filter. i always check the simple things first

 

Hi,

I installed a new filter half a year ago. I'm going out now with a new Ford fuel pump relay, maybe that willl do the trick. The fault checker I mentioned is my DTC tester. I'd really expect to see a fault there. I'll jump the wires to see if the pump spins too. And I'll try the rubber hammer but there is a skid plate in the way so it may not work so hot.

 

A "DTC checker" cannot, in any way, tell you that you don't have fuel pressure or why.

You need a fuel pressure guage and a multimeter to properly diagnose the system unless you plan on swapping parts until you get lucky.

Steve

 

Problem has been solved. Fuel pump relay was replaced but that did not fix it. I pulled the tank and checked the fuel pump. I sent 12 volts to it from a secondary power source and it worked. I hooked it back into the wiring harness but it did not spin up. Noises were under the hood- clicking at the relay and at the Idle air control valve. I unhooked the IAC and then reconnected it. I went back and set the key to off then to on and the fuel pump came to life.

Now she starts but I doscovered small holes in my exhaust so it's cat back time.

 

Ok, got the same problem replaced fuel filter and fuel pump worked for a while then stopped and I'm not driving this thing right now, just strating it and letting it run to keep the battery fresh. "I unhooked the IAC and then reconnected it" where is it the IAC? I'm about to drop my tank. So I would like to try the unhook thing. Thanks

MP

 

To answer the question you asked, behind the throttle body :


The black plug is the IAC connector.

To address the issue at hand: The IAC in the above post might have caused the no start, by not letting air pas the butterfly. This could have been a dirty IAC connector. It could also be :
IAC is dirty, and the plunger is not moving. Pic of clean IAC :

There are 2 bolts on the IAC, I seem to recall 8 MM, but they could be 10 mm. Short handled 1/4" ratchet, and deep well socket will get you at it from the pass side, with a bit of a reach.

My 2001 had a bad fuel pump relay.
Here is the thread where I took the bone head route to figure this out.
https://www.f150online.com/forums/sh...d.php?t=192096

Take note of checking for fuel at the schrader valve on the rail, before playing with the IAC.
You might want to do the run out of fuel / change the fuel filter procedure of cycling the ign from off to run ( don't start ) 6 times, to build fuel pressure, prior to checking for fuel pressure ( the fingernail in the schrader valve check, just like a bike tire ).
Cycling should get fuel pressure at the rail, if not check the inerita switch, then the fuel pump relay. In leau of a bench test, the jumper between pins 30 & 87 should run the fuel pump, without the key in the run position ( power to the N.O. contacts is hot at all times, key activates the coil to close the contacts ).

Just a thought to take the basic check first ( you make no note of what you have done, aside from the fuel filter change, and did not make note if you followed the new fuel filter procedure of cycling 6 times ).

 

Hey SSCULLY, I did the following and got these results:
1) checked Schrader valve and no fuel pressure at all
2) Went to Auto Store and purchased new a fuel pump relay fuse and still did not work.
But while I was checking for pressure at the schrader valve I came across this ground that was disconeccted. This would explain alot of the strange wiring type things I've been experiiencing. But I do not know where this ground is supposed to connect to. Here's a pic, any Ideals where it should connect too? Its on the back of the fire wall I have circled it in red:

 

I assume you are talking about the other end of it ?

I don't recall, and won't be by my dad's ( my old ) 2001 until this weekend to check on it.

Is this the same problem as the last thread ?

https://www.f150online.com/forums/sh...ight=fuel+pump

What happened when you pulled the bed, put the jumper back in the relay socket, and check with a meter for power at the fuel pump connector ?

 

Yeah, I metered it was getting 11.42 volts to the harness at the connector for the fuel pump. This is a new fuel pump with a new fuel filter installed. I'm just wondering if this thiing could go bad that fast.

 

And with the fuel line disconnected, will it push fuel out ?

You can go to the fuel filter, and use fuel / ac line disconnect tools to take it apart, and hand the felx end into a bucket. Jumper the fuel pump relay, and see if it runs fuel out the end of the line.

 

Sure I will disconnect the fuel lines and jump the fuel relay to see if fuel is making it out. One thing is I really dont hear the pump start up, but let me try and I'll let you know. Thanks

 

Well I went ahead and disconected just one fuel line and gave it the old crank and no fuel came out of the fuel line on the fuel pump. Although when I did remove the one fuel line there was fuel coming from the line going into the filter. I'm betting bad bad bad fuel pump? What ya think SSCULLY. I wonder if that ground not being connected is causing problems?

 

You did say you got 11.42 V at the fuel pump connector, so you have ground.
The only other test is disconnect the fuel pump connector, and plug in a external power source, to see if it changes.
To me it does sound like a bad fuel pump, but you would want to confirm it with the external power supply.