After a new starter, KSB solenoid, lift pump, battery cables, and cleaning up grounds and other little odds and ends, my best friends 1990 w250 still refuses to start when it's below 40 degrees. Cranks over nice and fast, grid heaters work fine, but it just won't fire. It takes like 5 sessions of 10 second cranking to get it to start. Once the truck finally starts and gets warmed up, it will restart on the first rotation like a champ. If it doesn't get below 50, the truck starts like a champ. I'm stumped.

 

Check the fuel lines maybe a slight crack or Plug it in and see if that makes a difference ?

 

When it gets real cold here...and I forget to plug in the truck...my truck will maybe crank two or three starter revolutions, and it's running.

Not sure why you'd be having so much trouble getting the motor to fire. How are the injectors? Maybe not getting enough fuel into the conbustion chamber?

 

We are going to check the lines going to the tank this weekend, I just have to figure out a way to test the injectors I guess. Truck does have over 400k on the clock.

 

check the compression. with that many miles, it could be low, and will take that much cranking to build enough heat to fire the fuel. once the engine is run, the residual heat in the block and head lets the engine fire quickly. I have no grid heaters, or plug in water heater. it starts with 3 or 4 turns of the starter at 20 degrees, and only 1 turn of the starter when it`s 30 degrees or warmer.

 

How about plugging the truck in and seeing if you have the same issue ?


If you don't, then you're looking at a grid heater timing issue, as they might not be staying lit long enough to function properly.... I have a hard starting issue that was easily corrected by plugging the truck in at night. Once I fixed the bad ground on the intake, the issue was resolved, and I don't have to plug it in anymore...

 

I would agree with a compressino check.

 

After I check all the lines going to the tank, I'm leaning toward injectors/compression being at fault, like you guys suggested. There is some visible blowby coming from the oil filler tube. Oil has about 2k on it since last change.

My truck (see signature) has no grid heater, and it starts on the coldest mornings here in Alabama (25-30f) one the first or second revolution of the starter. These motors were some of he easiest starting motors ever made, that's why this issue with my friends truck is so aggravating.

 

are you running summer fuel? has it sat for a while? some guys run a fuel condition/antigel

 

Valves ever been lashed? Valves out of adjustment can cause a hard start.

 

Valve adjustment fixed my neighbors truck that was doing the same thing.

 

Problem solved. Rewired KSB and shutoff solenoid to switches in cab, as well as installing a push button start. Never trust factory wiring.