Have a problem.... any ideas

[SFerrin]

I agree with 1stgen4ever. Perhaps make this your last diagnostic tool when you're down to replacing the pump anyway. It will at least confirm your diagnosis perhaps. I'm talking about one half a cup of tepid, not cold water, and carefully poured only on the portion where the fuel lines come into the injector body on firewall side. Or skip this all together because you don't want to harm anything that might still work. "First, do no harm. " may be your motto. Mine is, try to do no harm, until you get frustrated. Then repair the harm you stupidly caused.

 

[Headshot zod]

Ok I retightened my connections around the lift pump and now the truck doesn't die when I slow down. I'm going to drop the tank this weekend I hope. Anybody its a good idea to replace the fuel line from the tank to the lift pump? If so what size fitting would I need at the lift pump. Is it a 3/8 fuel line by any chance?



TIA

 

[JCrank]

Did you ever get to the bottom of the problem yet ? I may be experiencing the same problem on my 93. Did you see my 911 Won't Start post ?

 

[Headshot zod]

I usually don't check into that forum since I really don't have enough experience in troubleshooting yet.



But it sounds like you are driving my truck. Are you sure you're not taking mine when I'm sleeping? :-laf :-laf



I haven't dropped the tank yet. Next weekend. What I have been doing is just pointing the nose down when I park. And I'm using the "poor man's idle adjustment handle" by my right pedal to compensate for slowing down at the toll plazas. So I'm keeping my idle high enough so it won't die on me.



But I've replaced, the fuel filter, solenoid, lift pump. So I'll drop the tank and check that out.



I wasn't ready to try Sferrin's suggestion yet :--)

 

[JCrank]

:-laf Nope I haven't been borrowing your rig while you are napping. I haven't even been up to New Jersey for about 16 years. I do know that my rig is not getting fuel. The hows and the whys of it not getting fuel is what I'm working to figure out. I haven't put the new lift pump on yet, but I'm hoping this is the center of my problem. You can use the primer lever on the old lift pump to prime things up..... there is either an internal problem or the primer lever is broken, this is why I'm starting where I am.

Hope you get to the bottom of it. I have had to drive my Nissan Sentra for 2 days now and it sure ain't my truck.

 

[JCrank]

:-laf Nope I haven't been borrowing your rig while you are napping. I haven't even been up to New Jersey for about 16 years. I do know that my rig is not getting fuel. The hows and the whys of it not getting fuel is what I'm working to figure out. I haven't put the new lift pump on yet, but I'm hoping this is the center of my problem. You can use the primer lever on the old lift pump to prime things up..... there is either an internal problem or the primer lever is broken, this is why I'm starting where I am.

Hope you get to the bottom of it. I have had to drive my Nissan Sentra for 2 days now and it sure ain't my truck.

My statement about the lift pump primer lever... . it should say that you "CAN"T" use the primer because something is broke or messed up inside the pump.

 

[Nordby]

My 1992 had similar problems. It would exhibit vapor like signs (run out of fuel, hot days, under load towing), or stall under hard braking, etc. Typically warmer out when it would do it.



The way I would get it running again was to undo the gas cap (immediately when it died). It would pull a vacuum into the tank, not a lot, but some. So, I knew it was related to the gas cap venting, because it would run if I pulled it, or if it sat for a while.



My final fix for it was that I found a connection between the lift pump and the injection pump, hidden off under the grid heater/intake manifold. Looks like a solid metal fuel line, but if you feel all the way from the lift pump to the injection pump, there is a connection there. Mine was loose! So, as the vacuum built up and it took more and more to suck gas from the tank, finally the loose connection took over and it would suck air in that connection. It never responded to tests like spraying starting fluid on fittings, etc, because it would only leak after the vacuum started in the tank.



I went through the entire fuel tank drop thing, inspecting screens and checking clogs, replacing filters, checking return lines, the entire drill - what fixed me was that fitting described above.



thanks, good luck, jon.