6.9 Hard start issues

[dirtbiker]

Our 6.9 engine swap was NOT starting without ether (bad), and now WILL, but it still seems hard. We have been taking everybody's suggestions-thanks!-and not really seeing any clear cut problem. Though I do not have a tach, from what I can ascertain, it is cranking at 155 rpm. I have seen in a few places that "minimum required cranking speed" is 200 rpm. Batteries seem strong (2x1050 cca), cables are new 2/0 gauge. When cranking, we see smoke coming out the exhaust, just no start until the 3rd attempt. Is that consistent with too slow crank speed. It was suggested that we check the compression, but the speed in which this thing stops spinning when you shut it down seems as if it has TONS of compression. We will verify it as soon as we run down a checker, but is 155 too low to start?

Thanks for your help!

 

[lindstromjd]

This might have nothing to do with anything... but did you ever figure out your return line pressure issue? Since you're dumping all the return fuel right back in to the tank without the restrictor... I wonder if the fuel system is draining itself by sitting.

 

[dirtbiker]

This might have nothing to do with anything... but did you ever figure out your return line pressure issue? Since you're dumping all the return fuel right back in to the tank without the restrictor... I wonder if the fuel system is draining itself by sitting.

I had thought that there was some sort of pressure regulation at that fitting where the return lines meet toward the back of the engine, is that correct? Also, I replaced the fuel line between the filter head and injector with a clear line so that I could see if there were any bubbles, and there are none at all. I will check again in the morning, but after sitting a few hours, there were still no bubbles.

I'm just confused, because right after I replaced the glow plug relay yesterday, the thing fired right up with no hesitation... This morning it was having a hard time again. I took out a glow plug again and grounded it and turned the key to get the controller to cycle, and the glow plug glowed. So the glow plug system is good to go now. No idea what to do next though.

 

[lindstromjd]

Well, like I said, it was just a random thought. Might be worth checking out the next time you get it started, to see if you're keeping fuel in the system.

 

[dirtbiker]

Well, like I said, it was just a random thought. Might be worth checking out the next time you get it started, to see if you're keeping fuel in the system.

Yeah, no big deal man, I appreciate the thought... It is just really frustrating that it started no problem yesterday and then it was being stubborn again today.