No power at idle

[fpchief]

I just looked at mine, it has a clamp on both ends, I should be able to just put in a piece of tubing using existing end....maybe

 

[fpchief]

I forgot if the 8.3L MW pump is boost referenced, it should be. Make sure this pressure line is clear, connected correctly, and could check the diaphragm, spring, and internal movements associated with it.

Will have to see what line you are referring and will check it.

 

[smoke]

I wonder if the torque convertor clutch is locking up or trans starting in wrong gear from stop. When you sound you went to pull out from a stop and were also turning and it stalled. It reminded me of the tc clutch staying engaged causing engine to stall out. Do you feel all the gears shifting when you are driving? Could be starting out in wrong gear like 2,etc...

 

[fpchief]

I wonder if the torque convertor clutch is locking up or trans starting in wrong gear from stop. When you sound you went to pull out from a stop and were also turning and it stalled. It reminded me of the tc clutch staying engaged causing engine to stall out. Do you feel all the gears shifting when you are driving? Could be starting out in wrong gear like 2,etc...

I thought about that exact thing and it definitely has all the gears.

 

[74M35A2]

I thought about that exact thing and it definitely has all the gears.

Good point on gears. Once into the upper RPM’s of second, you should feel it do half a shift. This is the torque converter locking up, as a function check of that as well.

Here is the prototype clear return line, simply threads inline into the return fitting at the tank. I’ll test fit it later today on my truck, but should fit all M939’s, possibly others as well. I think the next one will not have crimped collars, or it will be optional.

 

[fpchief]

Good point on gears. Once into the upper RPM’s of second, you should feel it do half a shift. This is the torque converter locking up, as a function check of that as well.

Here is the prototype clear return line, simply threads inline into the return fitting at the tank. I’ll test fit it later today on my truck, but should fit all M939’s, possibly others as well. I think the next one will not have crimped collars, or it will be optional.

View attachment 793944

Mighty handy...I like.

I will see if I can feel the TC. So once it shifts (it's a hard shift) Into second as it is winding out I should feel the TC lock and then hit 3rd....right?

 

[fpchief]

Will have to see what line you are referring and will check it.

I don't have access to diagrams easily. This phone not helping. Is the diaphragm on the end if IP ? I take it the pressure line is the small one going in and end of IP?

 

[fpchief]

And to make things worse, the plug over aneroid adjustment is seized. Had it soaking and still nothing. About stripped now. Will have to fold another approach at removing.

 

[fpchief]

Found last night the guy I bought it from was having exact same issues with it in 2013 right after he got it from Uncle Sam. He hardly drove it and no real troubleshooting was done.....I wonder if it is a boost issue.

 

[74M35A2]

Mighty handy...I like.

I will see if I can feel the TC. So once it shifts (it's a hard shift) Into second as it is winding out I should feel the TC lock and then hit 3rd....right?

Yes. But the RPM drop for the converter locking is much smaller than the RPM drop during the shift. Also, the TC does not lock as soon as it shift into second, or is later in the shift. You may also be able to just put the shifter in 2 and hold there to see if it locks, I have never tried it.

 

[74M35A2]

I’ll look at my boost reference line later today and post pics of it has such. It should I imagine.

 

[fpchief]

Well, just went on a long ride. I 100% have TC lockup. I reckon that is good news.

This truck runs so good except for the hard 2nd upshift....will tackle that after this.

It's only issue is that not wanting to move sometimes from a dead stop.

 

[74M35A2]

Well, just went on a long ride. I 100% have TC lockup. I reckon that is good news.

This truck runs so good except for the hard 2nd upshift....will tackle that after this.

It's only issue is that not wanting to move sometimes from a dead stop.

Sight glass works amazing! They are listed for sale in the classifieds. Can get return side, suction side, or both to better identify a tank pickup problem.

Yours ships out tomorrow, Monday.

 

[fpchief]

That is excellent.

 

[74M35A2]

Here is a pic of the 8.3L boost reference line. Very short, goes from the intake manifold to the injection pump. Allows for increased fueling as the boost pressure comes up.

 

[fpchief]

Messed IP some....turned aneroid and it helped some. I hope that the

Here is a pic of the 8.3L boost reference line. Very short, goes from the intake manifold to the injection pump. Allows for increased fueling as the boost pressure comes up.

View attachment 794284

Gotcha. I did check and it is nice and tight.

 

[fpchief]

I received the clear fuel line diagnostic tool from 7435A2 today.

Installed in a snap and gave 100% good indication that I do not have any air being sucked in....this is way easier than starting troubleshoot blindly for possible air being sucked in.

 

[glcaines]

I know I need to turn the android, however the plug I have to remove is not wanting to budge. Dang near stripped it today. I have it soaking in PB right now. besides that I am asking if there is anything else I can do to help my problem. The truck has zero...I mean no power if there is any bind on the tires at startup especially on a cold engine. An example is I park in soft gravel and this afternoon I put it in gear and it would not move. In reverse is not a problem. Have had it shut down on me a couple of times when trying to start from a stop and turning at same time. This is a problem and I have to fix it. Otherwise it runs excellent and has excellent mid and top end.

Why would this be a fuel problem if there is no problem in reverse?

 

[Jbulach]

Reverse is roughly 2-1/2 times lower gear ratio.

 

[74M35A2]

Why would this be a fuel problem if there is no problem in reverse?

Symptoms are indicative of fuel delivery as one potential issue. Reverse could mask such low power situation due to its gear ratio being more than double that of first gear.