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Discussion Starter #1
I just bought a 1992 one ton with the 6.5 in it and some problems and questions have came up....The overdrive only works until the truck warms up, you can feel it downshift coming out of overdrive and it will not shift back until the truck has cooled for a couple hours. Also if I put it in first it shifts hard into second before reaching 3,000 rpms, just wondering if this is normal or not

If I drive it for a while it will sometimes try not to start, or if it starts it will die befor i make it 50ft. down the road...I did the lift pump test and the truck died so i'm assuming the lift pump is bad, but I cannot get it to start again. The truck will try to fire and die again, this has been ongoing for the last couple hours....Previous owner said the truck has new glow plugs, injector pump and fuel pump if this helps....

I'm a diesal newbie and not a very good mechanic so anyhelp will be appreciated..I'll fix what I can myself but if need be I am willing to put it in the shop...
 

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Discussion Starter #2
Today has been a learning experience...the truck finally started, apparently I didn't prime it well enough therefore it didnt start. Once it started I was able to determine that the connection to the lift pump was bad, now the problem is securing that connection so that the pump doesnt quit working while i'm driving down the road. Its been rewired already; the wires coming from the pump have been spliced to the wires on the male end of the plug but I think the problem lies in the female end of the plug, either where it is wired into the harness or in the plug itself. Can you replace these plug ends? My worry is bumps in the road causing it to lose connection, quit working and damage the injector pump itself...

help would still be appreciated
 

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Are you talking about the connection down on the frame rail, beside the lift pump itself? If so, you can just go to a wreckers, cut off a plug (both ends) and splice it in. Seal it up solid so there;s no shorting or getting wet.
 

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Welcome to the forum, enykamp..........

Lift pump runs only in START and when engine is running and oil pressure closes the switch in the Oil Pressure Sender, which also supplies signal to the oil pressure gage - the diaphragm heat-hardens, becomes less responsive.

Lift pump quits operating, but oil pressure gage still indicates - replace OPS to restore both functions if the connector-splice doesn't heal it
 

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Discussion Starter #5
the lift pump works now that I found the bad connection and know what it sounds like...The big problem is with the transmission and overdrive not working. the truck seems to shift normal other than overdrive quitting once it warms up for a few min. Hopefully it doesn't end up being too expensive
 

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coolant temp sensor can cause weird problems with OD....
 

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Check the transmission harness wiring under the truck, there - the heat sensor in the transmission causes similar symptoms when the TCM senses overheating.

Matter of fact, you may as well go thru the wiring harnesses and battery cables, cleaning and tightening and checking for broken\frayed wiring and oxidized\corroded connections.
 

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Discussion Starter #9
I checked it for codes this evening and it didn't show any...the good news is my lift pump connection problems are solved so thats one job crossed off on the list....
 
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