Still not starting or idling

[theanimal]

Ok so I finally got around to working on my m923a2. Changed the dip tubes (stainless), put all new Parker push lock fittings and lines from tank to lift pump and from tank to return on injection pump. New lift pump and cleaned tank completely. Also new fuel filter.
Truck will crank with stating fluid and stay running as long as you keep it revved to about 800. It will also drive around but has no get up and go. As soon as you let off the pedal and push the brakes the truck idles down until it dies. It won’t crank back up unless you spray stater fluid in the intake.
I broke all the lines on the injector pump while it was running and I get a strong spray from each one.
pulling my hair out over here

 

[98G]

You are most likely getting air in the fuel from somewhere.

 

[theanimal]

You are most likely getting air in the fuel from somewhere.

Ok so the only thing I know to do now is replace the lines from the lift pump to the filter and from the filter to the injector pump. Does anyone know how to buy these new? Is there a part # for the lines because they are all hard lines with banjos made in them ?

 

[smoke]

If they are all hard lines, you can replace the metal rubber washers that are on the lines. There should be two per banjo bolt ( one on either side of the line mating surface). From there I check the overflow valve on the pump. Also check the check valve in the back of the head on return line.

 

[WillWagner]

If it runs and drives but shuts off at idle or when you come to a stop, COULD be a messed up trans/converter. If the trans or converter is f-ed up, the engine is seeing a load all the time, the trans stops turning so it kills the engine. Does it smoke on start up? Easy thing to do to eliminate the trans/converter is to pull the bolts that connect the flex plate to converter, through the hole in the flywheel housing, and see if it starts/idles with the trans disconnected. Do this before you go screwing with pump settings.

 

[WillWagner]

Hard lines are pressure lines. If they leak, no air will be introduced into the system. You will just have a giant fuel mess.

 

[theanimal]

If it runs and drives but shuts off at idle or when you come to a stop, COULD be a messed up trans/converter. If the trans or converter is f-ed up, the engine is seeing a load all the time, the trans stops turning so it kills the engine. Does it smoke on start up? Easy thing to do to eliminate the trans/converter is to pull the bolts that connect the flex plate to converter, through the hole in the flywheel housing, and see if it starts/idles with the trans disconnected. Do this before you go screwing with pump settings.

But it doesn’t start in neutral on its own.

 

[WillWagner]

Exactly....IF the trans is FUBAR, it won't. It is trying to start fully loaded. A MINIMUM of 200 RPM....per Cumins...is needed to make one lite off...it will at a lower rpm, but NOT with a load. Before you go messing with pump settings, remove the converter bolts. It is...depending on the converter...6 to 12 bolts. Depending on the flywheel housing, left or right side accessible thru a flat steel cover with offset bolts, 1 top, one bottom.

In the pic, while it is for a B series, the plate/hole is the same...housing is upside down in the pic, but you hopefully will get the idea of what the plate looks like. Right side, apx 2 1/2 inch diameter open hole. The plugnext to it is for barring the engine over

Depending on what converter, there will be 6 to 12 bolts, either 1/2 inch, 13mm or 9/16 socket size. Take them out until you can see no more. Start the engine. If it starts, you have found the issue in the trans. Faster than screwing with the pump and finding out the pump ISN'T the problem.

 

[theanimal]

Exactly....IF the trans is FUBAR, it won't. It is trying to start fully loaded. A MINIMUM of 200 RPM....per Cumins...is needed to make one lite off...it will at a lower rpm, but NOT with a load. Before you go messing with pump settings, remove the converter bolts. It is...depending on the converter...6 to 12 bolts. Depending on the flywheel housing, left or right side accessible thru a flat steel cover with offset bolts, 1 top, one bottom.

In the pic, while it is for a B series, the plate/hole is the same...housing is upside down in the pic, but you hopefully will get the idea of what the plate looks like. Right side, apx 2 1/2 inch diameter open hole. The plugnext to it is for barring the engine over

Depending on what converter, there will be 6 to 12 bolts, either 1/2 inch, 13mm or 9/16 socket size. Take them out until you can see no more. Start the engine. If it starts, you have found the issue in the trans. Faster than screwing with the pump and finding out the pump ISN'T the problem.

Ok I will give this a shot but I guess I don’t understand why I can start it with a squirt of ether in the stack and it will sit there and idle in neutral all day if it’s the trans

 

[smoke]

You may have two problems. One still sucking air somewhere and or losing prime, reason for ether to start. Problem two is stall under load in gear low idle. Reason Will says check the trans is because they are know for problem with the lock up clutch staying engaged when you are hitting the brakes. That why Military retro abs on this trucks so the brakes wouldn't lock up if the clutch didn't disengage. In your one post, you said you replaced the fuel filter. Is the fuel filter a small inline filter? If so you have to watch what kind you get some do not flow enough fuel for this pumps. As far as the trans I believe you can disconnect something beside taking the bolts out to see if the Tclutch is disengage. But at the moment can't remember.

 

[theanimal]

You may have two problems. One still sucking air somewhere and or losing prime, reason for ether to start. Problem two is stall under load in gear low idle. Reason Will says check the trans is because they are know for problem with the lock up clutch staying engaged when you are hitting the brakes. That why Military retro abs on this trucks so the brakes wouldn't lock up if the clutch didn't disengage. In your one post, you said you replaced the fuel filter. Is the fuel filter a small inline filter? If so you have to watch what kind you get some do not flow enough fuel for this pumps. As far as the trans I believe you can disconnect something beside taking the bolts out to see if the Tclutch is disengage. But at the moment can't remember.

I only have the big screw on filter.
everyone said before that it could be sucking air so I changed everything from the lift pump back and there is no change. I have to doubt very seriously that it’s getting air from any of that.
what are other places that air could enter in?

 

[smoke]

When you say the big screw on filter, Do you mean a plain old filter head you screw on regular filter on or the see through canaster with cartridge? You could also put 3 or 4 psi of air on the tank and see if you get a leak. I read some where if the fuel shutoff solenoid is not adjusted right that it can partly block the fuel port there causing a restriction to fuel flow to the pump. Beside that check that the fuel shut off pulls in and stay in all way during crank and running. I personally have seen where the fuel shut off solenoid would pull in when switched to crank mode and than drop back out after leaving go of the switch back to run mode.

 

[theanimal]

When you say the big screw on filter, Do you mean a plain old filter head you screw on regular filter on or the see through canaster with cartridge? You could also put 3 or 4 psi of air on the tank and see if you get a leak. I read some where if the fuel shutoff solenoid is not adjusted right that it can partly block the fuel port there causing a restriction to fuel flow to the pump. Beside that check that the fuel shut off pulls in and stay in all way during crank and running. I personally have seen where the fuel shut off solenoid would pull in when switched to crank mode and than drop back out after leaving go of the switch back to run mode.

The only fuel filter is the one above the lift pump on the engine. It’s about a 3” diameter filter with the water drain in the bottom. I don’t have frame mounted filters or the inline.
I will check the fuel shut off and pressure up the tank

 

[98G]

These sensor thingy on top of the lift pump?

 

[theanimal]

These sensor thingy on top of the lift pump?

It was removed on the last round of suggestions and it had no affect.

 

[Andyrv6av8r]

I know a guy personally that had an inline electric fuel pump between the tank and lift pump. Might be something to try for some troubleshooting.

 

[WillWagner]

You didn't say it would idle all day in neutral, it would idle only if you held rpm above 800. What rpm does it idle at? You need to check pressures and restriction.

 

[Crf450x]

Have you checked lift pump pressure? Any smoke? Sounds like if you shut it off and immediately try to start it back it won’t start? I don’t think it’s sucking air. If you still think it is, pressurize the tank and see if you find any fuel leaking or try and start it while someone keeps pressure on the tank (be reasonable with the pressure)

 

[theanimal]

You didn't say it would idle all day in neutral, it would idle only if you held rpm above 800. What rpm does it idle at? You need to check pressures and restriction.

In gear it won’t idle. But out of gear it isles fine. So two different issues.
it isles around 600

 

[theanimal]

Have you checked lift pump pressure? Any smoke? Sounds like if you shut it off and immediately try to start it back it won’t start? I don’t think it’s sucking air. If you still think it is, pressurize the tank and see if you find any fuel leaking or try and start it while someone keeps pressure on the tank (be reasonable with the pressure)

I’m not sure how to check the pressure from the lift pump. It is the 2nd brand new one from Cummins though and the engine does the same thing. Once you start it with ether you can drive it around and it will idle in neutral. You can turn it off and immediately try to crank it and all it does is spin.