Hmmwv won't go on drive when in H but it will go on LOW

[Mogman]

If it were me and I was sure it was not a jelled fuel issue (I live in S. Texas so probably would never happen down here) the first thing I would do is check the return line which you said you did, if that was clear then I would clean the top of the IP as best I could and remove the return line fitting in the top of the pump, there should be a clear glass ball in there, a check valve, make sure there is not any black trash stuck in it.
Be very careful and CLEAN! do not get any trash in the IP and do not use any pipe sealing tape on it.
Edit, you cannot take that fitting apart, but you should be able to see light coming through the glass ball.

 

[Action]

You will get smoke if the engine is really cold and the glow plugs dont cycle.

Tell us exactly how you start it for the first time on any cold day.

 

[Lui1152]

If it were me and I was sure it was not a jelled fuel issue (I live in S. Texas so probably would never happen down here) the first thing I would do is check the return line which you said you did, if that was clear then I would clean the top of the IP as best I could and remove the return line fitting in the top of the pump, there should be a clear glass ball in there, a check valve, make sure there is not any black trash stuck in it.
Be very careful and CLEAN! do not get any trash in the IP and do not use any pipe sealing tape on it.
Edit, you cannot take that fitting apart, but you should be able to see light coming through the glass ball.

Awesome!

I'll start doing that! Hopefully it works.
Thank you so much

 

[Lui1152]

You will get smoke if the engine is really cold and the glow plugs dont cycle.

Tell us exactly how you start it for the first time on any cold day.

Usually let the glow plugs cycle at least 2 times. Then crank it. It take a while for it to go. No easy task to turn on.

 

[Mogman]

If it will start, then still smokes after a reasonable about of time running then the glow plugs, although could be having trouble are not the "problem" even with bad glow plugs as long as it starts it will clear up and start hitting on all 8 in a short amount of time.

 

[Lui1152]

If it were me and I was sure it was not a jelled fuel issue (I live in S. Texas so probably would never happen down here) the first thing I would do is check the return line which you said you did, if that was clear then I would clean the top of the IP as best I could and remove the return line fitting in the top of the pump, there should be a clear glass ball in there, a check valve, make sure there is not any black trash stuck in it.
Be very careful and CLEAN! do not get any trash in the IP and do not use any pipe sealing tape on it.
Edit, you cannot take that fitting apart, but you should be able to see light coming through the glass ball.

I have an update:




The fuel system was not the issue. I checked everything and still the same issues


I recently learned how to use the transmission light to get codes and got code 71.
After I got this code I replaced the engine (crankshaft) speed sensor but it did not fix my issue I still get the same code and still have the same issues.

I have not done anything else other than replacing the sensor.

Anyone have dealt with this before?
Any ideas?

Please

 

[Retiredwarhorses]

I have an update:




The fuel system was not the issue. I checked everything and still the same issues


I recently learned how to use the transmission light to get codes and got code 71.
After I got this code I replaced the engine (crankshaft) speed sensor but it did not fix my issue I still get the same code and still have the same issues.

I have not done anything else other than replacing the sensor.

Anyone have dealt with this before?
Any ideas?

Please

CPS has nothing to do with starting snd running engime, also…DO NOT double cycle the glow plugs to start your truck, you will only get away that a few times, or maybe not at all till it Melts your plugs.