I am going to change the fuel pump on my 91 explorer plow rig. I got a carter replacement pump to replace the one on the sending unit (a new unit from ford is $400+ more then the whole rig is worth). Any tips or tricks for replacing just the pump part of it? This thing will never be on the road agian so a mechanic I know said he has just cut the floor before to get access to them, which I think I am going to do.

The reason is that I think it is the fuel pump is the rig starts really hard. I need to squirt gas into the intake and then crank it over for a minute or better before it fires off. Once it starts it runs good. I took a pressure reading last year and it seemed on the border to a little low of acceptable pressure. I am going to check it again first.

 

Fuel pressure KOEO at the fuel rail, dont overlook the FPR they are known to go bad.

Fuel filter would be best replaced especially if vehicle has been sitting for long periods.

 

I pulled my tank out this morning because my sending unit tubes rusted thru. It was a lot of work to get the bolts out but they did come out, I too was going to cut a hole in the floor also but there is a cross member running over that part of the tank. I don't think you will be able remove it this way. Had he done this to an Explorer?

Now the bad news, My tank is plastic and the sending unit has a mounting ring that mates with a flange on the tank (appears to be molded into the tank, it is not bolted in)
I tapped on the ring and the ring popped right off, removed unit with fuel pump attached. The problem is that the molded in mounting flange is not functional any more. Rusted away
There is nothing left to mount the new one to.
I have a new sending unit coming this afternoon, I'm hoping it comes with a new mounting Flange and ring but assume it will be only the ring
I'll update you later today

1991 Explorer 240,000 miles, 8ft plow
What a work horse!!!!

 

To Wildstang: absolutely check the fuel pump regulator and the filter before replacing the pump. Is the pump making a very loud, strained noise? Usually they get to the point to where they either work or don't work.

 

Is there a way to check the regulator other then replacing it.

We have had this explorer for probably 10 years and I had a 92 ranger 4.0 during the same period and the explorer has pretty much always started harder. My ranger would crank maybe 3 times and start, the explorer 4-6 and it has just gotten progressively worse. It really sucks when it is 0 out with north wind and I have to screw with it to start. I have plug in the coolant heater cover the engine with towels and cardboard to get the engine as warm as possible and then squirt gas into the intake and crank it for a long time. Then it will almost act like it fires or hydrolocks and then will usually start. After it has been running and I stall it, it will usually start right back up.

Scooter Explorer1, I assume he has cut the floor before because I told him what I had.

 

I removed my tank from the truck because of the cross member over the fuel tank. If you cut between the cross members you may be able to see the sending unit but doubt you will be able to remove it.
Either way, don't mess with the sending unit unless you have to. My tank is plastic with a steel flange molded in it for the sending unit ring to screw on to, the flange is completely rusted away. I would need a new tank to fix it.
I am pulling the plow off this week, and retiring it.
18 years old and 240,000 miles, I'll miss it

Good Luck

 

I think some sheet metal and self taping screws and silicone would work for me. Hopefully mine won't be that bad but I know better living in Vermont.

 

I tried to start the b$#@%h last night but couldn't even get to start this time. I did my usual squirt gas into the intake, and usually it will start but this time it would almost but just not take off. I checked the fuel pressure with the key on and it is at 36psi. So I had bought a new pressure regulator and tried that, didn't have a lot of hope for it, and not really any difference. My repair manual says 40psi but is this system that finicky that it has to be exactly 40? I started it up a few weeks ago, of course it was a lot warmer out, doing the normal routine. I forgot to plug in the coolant heater this morning but will try that tonight when I get home. Other then the pump what else?

 

Are you getting spark to the plugs, and have you checked for loose vacuum lines?

 

Haven't looked for loose vacuum lines yet but which ones should I focus on. I think it is getting spark because it fires off but doesn't keep running, then keep cranking. Maybe the pump isn't able to supply the pressure while cranking, I guess I need to have my wife crank it while I watch the pressure gauge. Is there a temp sensor that could be screwed that is messing with timing or start up?

 

Check the vac lines at the vacuum tree located on the drivers side near the firewall. Make sure none of those nipples are open. If one of the lines is off, it will cause the engine to keep dying during the start process.

 

I will look them over, maybe the cold caused them to be slightly loose.

Would a slight leak cause the same problem when warm? Last year if I stalled it I would be able to start it right back up. The biggest problem is cold starts, the colder the harder to get it to start.

 

I was able to remove the sending unit without removing the tank, and it was pretty easy. You don't actually cut the cargo floor. Where the cargo floor steps down behind the rear seat you measure out about 5-6" from the foot of the slope and cut to about half way up that slope section. Go may 9-10" wide, gives you plenty of room to pick it straight up. I had the similar problem with the rusted metal retainer and ring so I just drilled two pilot holes, 180 degrees from each other and put in self tapping screws. Holds it in there just as securely.

Unfortunately it did not fix the start problem, just got the pressure from around 37 and got it up to 40psi. So I said screw it and found a 93 for $300. I need to swap driver doors, possibly seats and mount the plow and stuff on it.

 

Thanks for the update and sorry to here another one to be melted down
Good luck with your 1993

 

Thanks, I hated to spend the money but I need something that will start when I need it to.