'85 D150 Problem

[Buzz85]

Hey guys,

I'm new to the forum. I've been around as a guest-reader but only recently joined. Looks like a lot of good information on here!

I received my Grandpa's truck as a gift a few weeks ago. 1985 D-150 L6 - It's been his work truck for 20 years or so. I picked the truck up from Grandma's, where it had been sitting for a year and a bit. It started up first try and ran 3 hours smooth all the way home!

The next day, I tried to start it and..no luck. Not even one turn. I jumped it and it ran horribly for about 5 minutes of driving then coughed and sputtered and choked out. From then on, a jump will start it, but it only runs roughly for about a minute before the oil pressure drops (I assume because the pump isn't powered at the moment), then a major loss of power and eventual stall. There is electrical power to the rest of the car, but I didn't have time to test the battery before I had to come back out to the west coast!

Anyways, as long winded as that was...Does anyone have any clues they can give me about what might be happening? I'm still slightly an amature when it comes to working on my cars, but I have to start somewhere!

Any help is appreciated! Thanks

[Delray Dude]

My first random guess would be water or bad charging system.

If it ran fine on the way home - you mighta been bouncing it all over the place and there might have been a fair amount of water in the bottom of the gas tank - that might have been picked up and now some resides in the carb. That would give the symptoms you describe of running rough or barely at all.

As for the starting - clean all the cables - make sure you have a good ground to the engine block. Good solid connection to the starter.

Check the battery voltage - you may have a bad or weak charging situation - a good battery with a full charge will start the truck and you could probably get it home on the 3 hour drive with the alt not charging.

I'd charge the battery overnight and see if it cranks good after that - if so - while the engine is running - see what the voltage is at the battery - should be over 12 volts closer to 13.5 to 14 running - and a bitt off idle.
If it isn't and shows 12 and dropping then time to deal with the charging system - we can help you with that too.

[Buzz85]

Thanks for the help! I'll try that out :D

[Delray Dude]

also...


re-reading your post.

Check the oil level - oil pressure will drop off once an engine warms up - but not real quickly on a cold start.

Oil pump is mechanically driven inside the engine.

If you have low oil level - you may not have sufficient oil pressure to pump up the lifters and allow for proper valve opening and closing.

Low oil level will get pumped up intot he engine quickly and then little or none will be in the pan resulting in oil pressure loss

[acton mike]

i suspect that you have stirred up all kinds of trash in the fuel system and year old gas gets a little gummy/varnishy

drain the tank and fill with fresh fuel, blow out the fuel lines and get the carb cleaned out

With regard to the oil pressure, drain the oil and replace with fresh oil and a new filter

screw a mechanical oil gauge into the the sender receptacle and get a good solid reading on your oil pressure

[Buzz85]

I drained/replaced the fuel, changed the oil and tranny fluid, air filter etc before I drove it home. Thanks for the tips though! I'll clean the carb and see how that goes!

[Buzz85]

Delray - Oil is good. First thing I checked when it went out on me. Thanks!

[Delray Dude]

ok....just checking - i know that /6 motors are tough - but oil in them is a good thing! lol



sometimes you can tell if you got water in the carb if you look at the squirt coming outta the accelerator pump - look down the throat of the carb and move the throttle - if the stream is clean and gas - it'll vaporize in a short amount of time - water will sit there and do nothing....