The Diesel Garage banner
1 - 13 of 13 Posts

·
Junior Member
Joined
·
30 Posts
Discussion Starter · #1 ·
A few weeks ago, it was a cold snap here in southern iowa and our highest mileage '03 columbia with the 6nz C15 (885k) wouldn't turn over. After plugging it in for a few hours and putting a battery charger on it for a while and then having to put new batteries in it, it Still wouldn't barely turn over. So, we got a rebuilt starter for it, put that on, and it cranks really good now but no fire. If we spray it with ether, then it starts and all is well. Before all of this, it would start better in the cold than any of our other 3 6nz's. Now on a cold start on a 30 degree day, you can crank and crank and crank and it won't do nothing, but a small spray of ether and it fires right up and runs with no problem. My dad thinks fuel pump, but i'm not for sure how the system on those C15's works. Anyone have any ideas? Thanks in advance!!
 

·
Junior Member
Joined
·
631 Posts
A few weeks ago, it was a cold snap here in southern iowa and our highest mileage '03 columbia with the 6nz C15 (885k) wouldn't turn over. After plugging it in for a few hours and putting a battery charger on it for a while and then having to put new batteries in it, it Still wouldn't barely turn over. So, we got a rebuilt starter for it, put that on, and it cranks really good now but no fire. If we spray it with ether, then it starts and all is well. Before all of this, it would start better in the cold than any of our other 3 6nz's. Now on a cold start on a 30 degree day, you can crank and crank and crank and it won't do nothing, but a small spray of ether and it fires right up and runs with no problem. My dad thinks fuel pump, but i'm not for sure how the system on those C15's works. Anyone have any ideas? Thanks in advance!!
The fuel pressure regulator in the filter base is stuck open. There is a fuel line that comes from the back of the cylinder head to the filter base this is the return line. The fitting in the filter base for this line........ if you place your hand on the bottom of the base directly below this line, you'll feel a 1" nut.........this nut is actually the pressure regulator screwed into the base. Replace it
 

·
Senior Member
Joined
·
4,827 Posts
The C15 has a gear driven transfer pump on the front of the engine, bolted to the timing case on the drivers side. Has a few steel lines attached to it.

Held in place with two 12 point headed bolts and sealed to the case with an o-ring. As long as the steel lines loosen easy, it is a simple replacement. :)
 

·
Junior Member
Joined
·
316 Posts
If what mr.haney says does not fix it then you might have injector with bad o-rings.
 

·
Member
Joined
·
533 Posts
The fuel pressure regulator in the filter base is stuck open. There is a fuel line that comes from the back of the cylinder head to the filter base this is the return line. The fitting in the filter base for this line........ if you place your hand on the bottom of the base directly below this line, you'll feel a 1" nut.........this nut is actually the pressure regulator screwed into the base. Replace it
Anyone have the part numbers to those check valves handy?
 

·
Junior Member
Joined
·
30 Posts
Discussion Starter · #7 ·
I'll find out hopefully today if it fixes it depending on this darn freezing rain and someone getting to town to the cat drop off box. They said the regulator or as in their computer "valve, check, fuel" is like $24.?? Will let you all know if it fixes it or not. I'll have the part # as soon as I get it also Jfaulkner!
 

·
Junior Member
Joined
·
30 Posts
Discussion Starter · #9 ·
Alright, changed the regulator. Used ether to start it the first time, but then let it sit all day and it fired up faster than it ever has. We'll see how it's first start tomorrow is. Heck, if it still fires up so quick, we might be changing the regulator on our other 3 identical trucks too!
 

·
Junior Member
Joined
·
30 Posts
Discussion Starter · #11 ·
That's what they told us! We called them and said "uh... this valve doesn't look the same. the holes are smaller." We heard " it's an updated design. We change out ALOT of the regulators on the C15's. Usually the first thing to give problems with the fuel system when starting"
 

·
Registered
Joined
·
1 Posts
I joined this forum just now to say THANK YOU for this thread. Although 12 years old I was researching this exact same problem. My 05 sat for a while and the batteries took a dump. Bought 3 new batteries and the harnesses and she wouldn’t fire without ether.

I took the check valve out, cleaned it with a rag and air compressor and put it back in and my truck fired right up! I had already ordered the part using the part number from this thread so when it comes in I’ll swap it out or keep it in the shop for later use if needed. Amazing what forums have provided!
 
1 - 13 of 13 Posts
Top