Need some help with 6.9

[GavinPCB]

Ive had a 6.9 For about six months now. It’s ran pretty good until a few months ago. I did the t-19 to ZF5 conversion and while the truck was down I decided to install new injectors and fuel lines.

One morning it wouldn’t start. It had a drain back issue so I tracked it back to the water separator and bypassed it with a inline electric pump from Napa to assist with priming if need be and my lift pump was suspect at this point.

Then replaced the 6.9 fuel header with a 7.3 header to make up for the lack of a water separator.

The truck won’t start. Just crank. I’ve tried bleeding it at the injectors and Schroeder valve multiple times. I know I have a leak on the #1 injector from the o rings. I don’t believe that would cause no start situation.

The glow plugs were replaced when I got it along with the controller. I swapped the IP with one from the junk yard just to see if it would change anything. At that point I was able to get some fuel to the injectors. But the injectors don’t seem to pop. I also replaced the FSS with a new one just for fun. Anybody have any other ideas?

 

[Thewespaul]

Where did the injectors come from? It could be if they sat on a shelf for a long time and the pintles are stuck shut

 

[GavinPCB]

Where did the injectors come from? It could be if they sat on a shelf for a long time and the pintles are stuck shut

I got them from R&D. I believe they were the stage 1 injectors.

 

[Thewespaul]

You should be fine then, try taking out your glow plugs and spinning the engine over. The extra rpms with no compression will purge any air out extemely fast.

 

[GavinPCB]

You should be fine then, try taking out your glow plugs and spinning the engine over. The extra rpms with no compression will purge any air out extemely fast.

I’ll give it a try. Thanks. Just in case, any other ideas?

 

[sjwelds]

You didn't say, but if they aren't beru glow plugs, that could easily be the problem.

 

[GavinPCB]

You didn't say, but if they aren't beru glow plugs, that could easily be the problem.

Motor craft glow plugs

 

[DrCharles]

Motorcraft = Beru

 

[riphip]

The truck won’t start. Just crank. I’ve tried bleeding it at the injectors and Schroeder valve multiple times. I know I have a leak on the #1 injector from the o rings. I don’t believe that would cause no start situation.

If it will leak fuel, it will suck air

 

[Knuckledragger]

Step by step. First, determine if you have any leaks and fix them. Next, determine if you are getting fuel. The 6.9 filter head has a schrader valve for this purpose, I do not remember if the 7.3 head has one also. If you have fuel pressure, do you have air intrusion? Again, the schrader valve will help with this, but also crack injector lines one at a time while cranking to bleed and learn.

Now you may need to check cylinder compression. Remove all glow plugs and spin engine a bit to get oil to flow. Compression in a 6.9 should be a minimum of 350 psi, up to 400 psi. The engine is not likely to start under 350 psi.

Other things to check: fuel level in tanks (use a stick), GP controller for operation, pop test injectors.