I posted in another post about my 86 2.9 4X4 with the fuel system problem. It ran fine until the fuel filters were replaced. Then it would not start then the high pressure fuel pump on the rail was replaced. It started then, but was running very rough. I was going to take it to a frien of mine who a cert mech, now I can't even get it to start! Acts like it's not getting gas at all? Anybody got any ideas to just get it going at all?

Oh another question I can't find the reset switch for the fuel system. I've checked the book but I can't find it. Would there be any use in resetting the system?

 

the reset switch is on the passenger side, behind the carpet on the fire wall (in the cab). its a black with a (usually) white button on top.

are you getting fuel @ the rail on the engine? and is your fuel pressure regulator working properly?

 

Thanks I found the switch. I reset it, but it nothing changed. I hear the pump trying to work, but it still will not start. I'm not sure if the fuel pressure regulator is working properly.

 

you may have air in the line from fuel filter change. also it may help to cycle the key on and off (with out cranking the engine) to get the fuel prime up to the rail.

 

Pick up an El' Cheapo Deluxe fuel pressure tester from a store like Harbor Freight. (make sure to get the one that covers FUEL INJECTION LOL!!) (yeah..they make a low pressure fuel tester as well)

The only way to see what the fuel system/pumps is doing? Will be to put the tester on the fuel rail. Put the tester on the rail, and turn the key to 'on' (not starting it yet) a few times to prime the system. You should have about 38-40lbs of fuel pressure on the gauge. USE CARE!! installing/removing the tool can give you a gas shower. I always suggest wrapping the end with a few shop rags while doing this. Better a gas soaked junky rag, then your street cloths.

Now if you have good fuel pressure, and you have verified there is no fuel present in the vacuum hose leading to the regulator? (when they fail? It will allow fuel to enter the intake via the vacuum hose) Then we need to start more diagnostic work.

Sense that beast uses two fuel pumps? If the intank pump went south? It won't get the fuel to the pressure pump on the rail. Have a helper turn the key a few times to 'on' and give the tank a listen. You should hear not only the pressure pump kick on, but you should hear the intank pump kick on.

S-

 

Going to try it this weekend! Thanks all.

 

Assuming your pressure is good.

Try removing the gas cap (easier to hear the pump too), crank for about 10 seconds, wait a minute or so, repeat four times. Should start around the 3-4th time if the prime is the problem.

 

Well, no need to crank it..

A few questions... Why were you changing the fuel filters? Normal maintenance? Just figured it was time? Did you sense some sort of fuel system issue?

OK, Grab yourself a couple of clean two liter pop bottles. You've got an outlet line from the tank/low pressure feed pump. Disconnect that line prior to the high pressure pump. As you're retracing the lines and connections, make sure you've got the correct lines, not the return to the tank, going to the high pressure pump. Anyway, dis connect that fitting and put the end in the pop bottle. Have your girl turn the key 'on'. The pump should run for a few seconds, then stop. This is what primes the high pressure pump. There are a few rules that need to be met for the fuel system to work. If you get fuel out of that line, it is the feed to the high pump. Now disconnect at the fuel rail prior to the presure regulator and test the same. You should get a good blast from the high pressure pump. The plastic bottles work great. Take other safety precautions as necessary. Break the system into pieces. Test each piece to find out what's wrong.

Honestly, this sounds like a case of the wrong lines hooked up to the wrong port, or a filter installed backwards. Did you try removing the filters and starting the engine? When something is malfunctioning after a maintenance act, the first thing I do is remove every bit of the maintenace act that I did to find what I did wrong.

-Steve

 

I think Steve got it; fuel filters backwards and/or fuel lines reversed?

 

> Well, no need to crank it..

Actually, yes, that is why I said it. I have done it enough times to know it works vs. just cycling the key.

 

Go to the basics first. If you have fuel and spark it should fire. Crank it a few spins and pull the #1 spark plug and see if it is wet with fuel. If none, retrace what you did to make sure everything you changed out is installed correctly. If your getting fuel. Check your electrical connections on the distributor and such. It would not be the first time someone was messing with the fuel and accidentally knocked a wire loose from the ignition system and/or computer? Do the old screwdriver in the plug wire short test. That should tell you if there is spark. If that is good and it still wont start, you need to trace the complete system out one component at a time.

Tim

 

Well, it's fixed. Put a new pump in the gas tank.

 

I was gonna say check the MAP sensor, the vacume tube goes bad and you dont see it. Runs like crap.
Keep Em' Twistin'! Bob B.