I must have an air lock in my 1994 located in the injector pump. I can crack the supply line at the pump and get plenty of fuel when I pump the primer. I still can't get it to start. I cracked an injector and am getting no fuel. How do I get fuel through the pump to prime?

 

TJ I always just crack the injector lines open, and crank it over until I get fuel. of course, keep a towel handy and DO NOT let anyone near the engine bay. After you get some fuel, tighten up the lines, wipe up the fuel that sprayed, might want to let it sit for a few minutes to evaporate. Then try it again. there's probably a much easier way, and someone that knows better will chime in, but that's always worked for me. Oh and don't crank it over more than 15 seconds to avoid burning the starter up. Give it time to cool down if once isn't enough.

 

Check your shut down solinoid. After it cranks, leave the key on and pull up on the plunger, if it goes up the starter contacts are bad. If the plunger is up and it wont start, put a fuel pressure guage on it. the lift pump may be bad or the overflow valve may be bad.

 

I checked the shutdown solenoid, it is OK. The boot is deteriorated badly but the solenoid is still functioning properly.

I'm assuming the primer pump is not capable of getting fuel past the pump to the cracked injector lines and that the motor will have to be turned over several times in order to get fuel to the injectors. Am I right here?

How long do I typically have to turn the engine over to get fuel to the cracked injectors?

My thumb feels like hamburger!

 

Crack the line at the overflow valve with the shutdown solenoid pulled up and pump.
Also make sure you have removed air from the filter by pumping with the bleed screw on top of the filter housing open.
Usually cranking for 15 seconds will get fuel to the injectors.
Use a short wooden dowel to save your thumb.

 

Go inside and unscrew the handle from a "Plumbers Helper"and use that. Your thumbs will love you for it.
Just try not to tear that little rubber cover on the lift pump.
If you listen carefully, when you get fuel up there, you can hear that overflow valve softly 'squeeking" as it bleeds off fuel thru the inj pump.

Keith

 

Leaving from work to go try it. I'll try to update this post tomorrow morning if I have any luck or just have more questions.

Update:

No dice! I cannot get fuel throught the bleeder on top of the filter housing. The reason I'm in this situation is because I unplugged my heater/strainer when it fried, the element connection was wet with diesel fuel (leaking through the pins), when I did this it ran for awhile, belched a big plume of white smoke, and dead ever since!

I'm assuming I'm sucking air through the electrical connections of the heater/strainer as fast as I'm pumping it out with the primer which explains why I can get it to bubble but never get any fuel to run out on top of the filter. I have a new lift pump, overflow valve and fuel lines in a box, waiting until I get my heater/strainer parts from Cummins before I tear into it.

I was just hoping I could get it running long enough to get it pulled into the shop, the gravel driveway isn't my favorite place to work! Is there any way to plug off the heater/strainer leak until my parts come in? I'm missing my baby!

 

Hey, I've updated my last post. Let me know what you think.

 

Hmmm. I wonder,.. Just a thought but, unscrew the fuel tank cap and see if there is a partial vacuum in your tank.
Probably not by now, but if there is, it could be making it harder to catch prime.
I have a plugged tank vent line and it sounds like "WHOOSH" when I pop the cap to fill it. I figure it COULD exacerbate an existing air leak/difficult priming problem. It hasn't caused any fueling problems yet.. It is just one of those things to work on when I get time.

That fuel heater connector leak is a common problem and thanks to DTR, I have been forewarned and I'm watching for various minor pitfalls like that...


Keith

 

If it was leaking at the fuel heater the fuel would have air bubbles at the the bleed screw on top of the filter while pumping the primer and if it was leaking enough to suck air right after priming would have an obvious diesel leak.

If the cam is stopped in exactly the wrong place the primer button won't work well if at all. Crank the starter for a second to change the cam position.

If you have an air compressor the fast way to prime is to wrap a air nozzle in a rag and pressurize the fuel tank fill hose with the bleed screw open. Don't get carried away and blow up your tank. With an extra person under the hood this method will also pinpoint any leaks.

 

love the air presure trick, works like a charm for some things. Nothing like a good push to get it goin... presurized tank and a fifteen second crank with a couple injector lines cracked and you should get fuel if it starts shut it off quick and get those lines tightened again b4 ya diesel down the whole engine bay!

 

The water seperator/fuel heater is connected to the pump with a hose and the fuel line from the tank is connected to the fuel seperator/heater, I don't know what size the line is but it might work to hook the fuel line directly to the pump if it fits. I think the 94 has the same pump as the 95's with the push button primer not the lever on the side of the pump, so the cam position wouldn't matter because the primer is a seperate pump not a lever moving the main pump.
I know the feeling of gravel stuck to your rear and freezing to the ground and fuel lubricating your armpits while snow blows up the mechanics crack feeling. I used to run road service in Mich. I feel for you. Good luck

 

I did the "pressurizing of the tank trick" last night. I set my regulator at 20 pounds and I connected a 10 foot section of hose to the end of me air nozzle so I could get up in the engine compartment and see what was going on. I cracked the bleeder valve on top of the filter housing and hit it with the air. I finally got fuel through the valve, and ................ a SOLID stream of fuel about half the size of a pencil was running out the electrical connection of the heater/strainer. No wonder I couldn't get fuel through the top of the filter housing. No wonder this thing has been acting just like me every day.............sputtering, coughing, smoking, and doesn't want to get going in the mornings.

Guess I'll just have to be patient until my heater/strainer parts get here from cummins.

Here's what I have planned while I have it in the shop, yeah I'm getting into the heated shop with a lift one way or the other. Can you guys give me anything else I should be doing while its in there as basic maintanence?

1994 with 170,000 miles

1. replacing fuel lines with hose from engine to the tank
2. new overflow valve
3. new lift pump
4. rebuild the heater/strainer
5. checking the valve clearance

Thanks in advance for all of your help! I'm a loyal DTR reader now!

 

I personally would skip the lift pump but replace the starter contacts while you're down there. Buy them here http://www.fostertruck.com/dodge/default.htm
if you don't have good fuel hose this an excellent source for high quality.

I've taken the pressurize the tank method a step further since I use it so often by drilling and tapping a port in an extra fuel cap and installing a male air chuck. Never use the stupid primer button anymore even for a routine filter change. I set the regulator at 5-10 psi.

 

I had a JD tractor with no fuel gauge and a cap with an air valve in it so when the gung ho boys would jump on w/ out checkin the fuel I could get it runnin in a snap,