My '89 Cummins is a bit hard starting when cold. I have had other Cummins engines start with no problem when in the 20's or even colder. Yesterday I started my truck (I had not started it in over a week) with the outside temp in the low 30's. It did start but took a lot more cranking than it should. Tons of white smoke untill it warmed up.

It can sit for weeks in below 0 temps and fire up as soon as you hit the ignition if it is plugged in for a couple hours first.

Is there something I can do? The engine only has 290,000 miles so it can't be wore out

 

I have been fighting the same issue with the wife's truck.

I suspect an air-leak that only opens when the block is cold.

I sort of think I have fixed it; but, with our extreme temperature fluctuations around here, it is hard to say; it may not yet be fixed.


I sort of think the culprit has been the fuel-heater gasket, which I just recently replaced.

Her truck will fire on the first piston-lift, regardless of outside temperatures, so long as it has been plugged in for a couple hours.


Let it set unplugged in below twenty-degree temperatures and it may, or may not, start.

In these situations, a light misting of ether has always fired it off.

 

first check you have no air leak and all the fittings are tight then check the KSB it advances the timing when cold to help it start easyer

 

I have the same issues when it is cold. I have removed the grid heaters. Check to see if the grid heaters are working. They do make a difference starting a cold truck when it drops below 40 degrees F.

 

try giving it a little fuel when cranking

 

Thanks for the input guys!
When you are talking leaks, do you mean intake air or fuel, or both?
Does the '89 Cummins have a fuel heater? Is it electric powered? Where is it?
If I under stand the KSB on my truck it has power to it all the time with the ignition on, and is slow acting. Next time I try to start the truck cold I will unplug the KSB and see if that makes a difference.

 

We're talking about air getting in the fuel supply lines.

The fuel heater is between the filter and the head. It is supplied with 12 volts any time the key is on, but it has an internal temp switch that kicks on around 60 degrees.

Unplugging the KSB won't help the start but it should reduce the white smoke afterwards.

 

I have never really understood how the earlier KSBs worked, seeing as they are all-the-time ignition-HOT, wired directly to the fuel shut-down solenoid wire.

I see several 89-90 trucks that have no wire connected to the KSB; would not the valve be ON (or whatever) constantly ??

Thanks.

 

Non-intercooled KSB's are run off the little brain box on the firewall. They get power except when the intake air temp is low.

In an engine swap situation where the brain box has not been used, the non-intercooled KSB ought to be wired to the shutoff solenoid. You'll get a minute or so of "KSB" operation on a cold start because the wax motor takes some time to warm up.

If the non-intercooled KSB is not powered, then the pump is running in "KSB" mode.