Starting Help

[frontiersman]

I am trying to help my friend diagnose and solve a starting problem he is having with his M1028 (which he wont sell to me lol). When truck is cold, you turn on key and wait for the WAIT light to go out, then it starts instantly. If you run thr truck to operating temp, and turn it off, it wont start to save budda. If you let the truck cool down for 30-45 mins, it starts right up. Any ideas? Thanks in advance!

 

[m4A1]

I've had a problem where after it runs at running temp and then turn it off and sit for a half it won't start. It was because the temp switch for the glow plugs says it is warm enough and would not allow the glow plugs to activate. I rigged a bypass switch to activate the glow plugs manually when that happens.

 

[frontiersman]

Ok, so in theory the temp sensor is the problem? Does anyone have a part number and where one can be purchased? Where on the engine is the sensor located? Thanks!

 

[Westech]

back of the intake. get the Manuals it will help a ton

 

[Croatan_Kid]

It's not that the sensor is bad, just that it's warm enough to tell the GP curcuit not to engage the GPs. So if you rig up a manual by-pass you can use them for a "warm" start and it'll start much easier. There's a sticky at the top of the page on a manual controller setup.

 

[mangus580]

Are you saying if you turn it off, and try to start it right back up it wont?

This is the symptoms of a really tired injection pump If I remember right....

 

[frontiersman]

No, it will start right back up if you turn it off, and then start it back up. If you turn it off and leave it off for a few minutes, sometimes it wont start back up until it cools down. Doesnt happen everytime. He would like to keep it original if possible, so doing the manual bypass would be his last resort. So the TM will give the GM part number for the temp sensor?

 

[Croatan_Kid]

The point I was trying to make is that the temp switch is most likely working perfectly. It's just at the point between needing glow plugs and not needing them, so it's iffy sometimes. To answer your questions, yes, I think the part number is in the TM.

 

[CCATLETT1984]

to test that, pull the plug from the temp switch next time it wont start, and put a paper clip in to bridge the connection. that will make the engine think its cold and the plugs will glow.

 

[frontiersman]

Thanks CCATLETT1984! We will try that! If the pulgs glow and the engine starts, then what part would need replacing? Is the manual overide the only fix?

 

[CCATLETT1984]

if that does fix it, then you have a bum switch.

 

[CCATLETT1984]

easiest thing to do would be to add the manual glow plug conversion to the truck, it will leave the stock system intact and you can just glow the plugs a little when needed.

 

[frontiersman]

Ok, may be forced to do the manual mod. The bum switch would be the sensor, or the glow plug controller switch?

 

[CCATLETT1984]

the sensor in the block

 

[frontiersman]

Ok, lol. I am learning. Hopefully I will have my own M1028 next week if things go as planned! Then will upgrade to Humvee wheels and tires......then maybe look for a military trailer? LOL!

 

[CCATLETT1984]

for the trailer a m105 is too much weight to pull with our trucks, you need to find a m101, the m101a2 has surge brakes, and the m101a3 has humvee rims and tires.

 

[rickta24]

i am having this exact same problem. i tried installing the manual glow plug switch...still could not get it started. when i turn the manual switch on, my gen 2 light goes a little dimmer. then i turn off the switch and gen 2 gets a little brighter. could the problem possibly be a bad ground?