Starting trouble

[bikerbarbie]

Hi Everyone,
We are having some trouble in the morning only. Truck turns over, idles really rough for some seconds and dies, does this a few times. Temp is around 60-70F, if its plugged in for an hours or so it starts up, idles smooth and runs great till the next morning, does it all again. new fuel filter, glow plugs all done this year as well as relay, new starter and new batteries. We are perplexed, sounds like it not getting fuel, fuel bowl fills right up when you turn the key. Any suggestions would be helpful, relay again? Do both relays contribute to starting and we keep hearing about the PCM, this is very expensive, can we test it?? and where the heck is it exactly? Book says go to dealer.

Thanks for any help

 

[BJS]

if its plugged in for an hours or so it starts up,

This comment points me to your glow plug system.

The two relays that are on the top of the motor are: one for the glow plugs, the other for the intake air heater (IAH) sorry but I don't remember for certain which one does what but I believe the front one is for the glow plugs

The IAH is not needed, it was not on my model year and many who got the option have removed it to help with better air flow into the engine. Many in colder climates than you are describing.

There is a possibility of problems with the valve covers or under valve cover wiring harnesses that lead to the glow plugs they are easily checked by testing the resistance on the pins for the glow plugs from outside the valve cover at the engine side connector - just check for resistance to ground which should be below 0.3 ohms...

Also check the voltage that is getting to your glow plug relay and also check the voltage drop across the relay when it is engaged. Even though your glow plug relay may be newer there are plenty of cases where the new ones fail very quickly due to poor mfg. And when helping someone else we went looking for one locally only to find that all of the parts stores were trying to give us a fender mounted starter relay which does look almost the same but will only function for a short period of time.

 

[bikerbarbie]

I think you're right

We plugged the heater in all night and truck started right up this morning. So off to replace relay!! Hopefully that's it. PCM is very expensive in comparison. Sure shouldn't have to plug it in at these temps. Our Haynes manual says relay at back is glow plug relay, but we're going to replace both anyway. I guess tomorrow morning will be the test!!!! Will let you know how it works out..