Fuel issues 91 cummins in a 69 dodge
#1
11-27-2013, 03:29 PM
Fuel issues 91 cummins in a 69 dodge
Greetings,
I apologize if this is covered somewhere and I’m just not understanding. I’m stuck, at a loss, and clueless. help?
This will be long, because I want to make sure all the pertinent information is given.
I am in the process of building a 69 Dodge W250 crew cab with a 91 Cummins in it. This is not an engine that I bought and don’t know how it runs. I pulled this engine from my 91 dodge D350 when the body had finally fallen apart to the point of uselessness. The engine was running great.
After several years, I’ve reached the point where the engine is mounted, wired, plumbed, and was ready to fire up. I’m using the stock 91 radiator, exhaust, and fuel pump. I have the one wire that used to power the coil running the injector pump, and I have the air heaters plugged to a momentary switch on the dash so I can manually operate them should they be necessary. I used a diesel fuel tank from a 93 Ford F350, which is presently held under the truck with bailing wire. the return line and main line are plumbed with rubber line to a steel line that runs the length of the frame rails, and then the main line goes into a large NAPA auxiliary fuel canister fuel filter and water separator.
I read a number of forums on how to bleed the fuel system, so I got fuel in the tank, and began to use the priming handle on the mechanical pump, cracking the bleeder valve every few pumps. Nothing came out. I disconnected and went straight to a fuel can, and still nothing came out. I poured fuel down the line with the bleeder bolt open and fuel came out. Figuring the fuel pump had died from sitting for 5 years, I bought a new one and put it in. Now fuel and air bubbles would come out of the bleeder bolt when I pumped. Reconnected the fuel line to the main tank and bled until I could do 3 sets of 8 pumps with no air coming out the bleeder bolt.
With that done, I turned the key on, and began bumping the engine over with the starter to bleed the injectors. Crank for a few seconds, and then go crack the nut on the injector closest to the back. repeat until diesel came out, then move onto the next injector. By the time I’d gotten to the third injector, the engine started and ran very very poorly. I stopped it, and continues the process, only now I’d have to crank it, the engine would start, I’d kill it, and then open the injector. Once all injectors had fuel coming out, I thought it might run better. it didn’t. When I try to give it throttle, it smooths out with just a little throttle at what I’d guess to be about 100 rpm. if I try to rev it, it dies. if I try to hold it at a higher rpm, it dies. And on a whim, I opened the bleeder bolt and there was air there again.
Back to hunting through forums. A youtube video shows that I can bleed the injectors while the engine is running, but to be very careful. Next time, I went back out, did the priming handle on the pump until there was no air at the bleeder bolt for 3 sets of 8 pumps, and then cranked with the starter. the engine started immediately and ran poorly. I started at the back injector and cracked the nut very cautiously. it squirted small sprays of diesel all over the place. I did that with each injector in turn, noting that when I tightened the nut back up, sometimes the engine would smooth out. the 4th injector from the back and the front injector both cause the engine to run very badly when opened. The other injectors didn’t really seem to have much effect, except that sometimes when I closed them it would run better for a bit. Nothing I did seemed to make it smooth out (or as smooth as a diesel ever sounds:-). Just to see, I checked the bleeder bolt again, and it spewed air. lots of air.
Back to the internet for help again. The general consensus seemed to point to there’s a leak in my incoming line somewhere. the leak doesn’t have to be big enough to let fuel out in order to let air in. So I took the line off at the tank, and put 15 psi air to it while spraying down all the connections with soapy water. I found two leaks and fixed them, figuring that NOW I could bleed the thing and it would run good again.
Go through the same rigamarole: bleed the bleeder until there’s no air (which seems to take longer each time I do this), and then bleed the injectors. By this time, the engine fires up instantly, so I’m always bleeding the injectors while it’s running. Still runs poorly. still dies if I try to give it throttle.
After reading forums again, it appears that there’s a possibility that the pickup in the fuel tank is allowing air to get in. So I disconnect the fuel line at the tank and put it into a fuel can full of diesel, it’s buried 8 inches into the fuel, so there should be no air. But the same issue occurs, but this time it does somethings strange: when I open the 4th injector, the engine runs worse, like it always does, and then it dies. That’s the first time it’s died at idle. It won’t restart. I checked the bleeder and lots of air came out.
Then I removed the auxiliary fuel filter from the line, in case that was a problem. Same deal, only now the truck won’t start. I changed my process a bit: Crank the engine, check the bleeder, crack each injector, and then check the bleeder again. And I still wind up after a while with bunches of air in the line. the truck now runs for a second and then dies.
I’m at a loss. Do I need to remove the stock filter and re-fill it with diesel? Am I introducing air when I crack the injectors open? I rechecked the lines with soapy water and pressure, and there are no leaks that I can find.
Any help would be appreciated.
I apologize if this is covered somewhere and I’m just not understanding. I’m stuck, at a loss, and clueless. help?
This will be long, because I want to make sure all the pertinent information is given.
I am in the process of building a 69 Dodge W250 crew cab with a 91 Cummins in it. This is not an engine that I bought and don’t know how it runs. I pulled this engine from my 91 dodge D350 when the body had finally fallen apart to the point of uselessness. The engine was running great.
After several years, I’ve reached the point where the engine is mounted, wired, plumbed, and was ready to fire up. I’m using the stock 91 radiator, exhaust, and fuel pump. I have the one wire that used to power the coil running the injector pump, and I have the air heaters plugged to a momentary switch on the dash so I can manually operate them should they be necessary. I used a diesel fuel tank from a 93 Ford F350, which is presently held under the truck with bailing wire. the return line and main line are plumbed with rubber line to a steel line that runs the length of the frame rails, and then the main line goes into a large NAPA auxiliary fuel canister fuel filter and water separator.
I read a number of forums on how to bleed the fuel system, so I got fuel in the tank, and began to use the priming handle on the mechanical pump, cracking the bleeder valve every few pumps. Nothing came out. I disconnected and went straight to a fuel can, and still nothing came out. I poured fuel down the line with the bleeder bolt open and fuel came out. Figuring the fuel pump had died from sitting for 5 years, I bought a new one and put it in. Now fuel and air bubbles would come out of the bleeder bolt when I pumped. Reconnected the fuel line to the main tank and bled until I could do 3 sets of 8 pumps with no air coming out the bleeder bolt.
With that done, I turned the key on, and began bumping the engine over with the starter to bleed the injectors. Crank for a few seconds, and then go crack the nut on the injector closest to the back. repeat until diesel came out, then move onto the next injector. By the time I’d gotten to the third injector, the engine started and ran very very poorly. I stopped it, and continues the process, only now I’d have to crank it, the engine would start, I’d kill it, and then open the injector. Once all injectors had fuel coming out, I thought it might run better. it didn’t. When I try to give it throttle, it smooths out with just a little throttle at what I’d guess to be about 100 rpm. if I try to rev it, it dies. if I try to hold it at a higher rpm, it dies. And on a whim, I opened the bleeder bolt and there was air there again.
Back to hunting through forums. A youtube video shows that I can bleed the injectors while the engine is running, but to be very careful. Next time, I went back out, did the priming handle on the pump until there was no air at the bleeder bolt for 3 sets of 8 pumps, and then cranked with the starter. the engine started immediately and ran poorly. I started at the back injector and cracked the nut very cautiously. it squirted small sprays of diesel all over the place. I did that with each injector in turn, noting that when I tightened the nut back up, sometimes the engine would smooth out. the 4th injector from the back and the front injector both cause the engine to run very badly when opened. The other injectors didn’t really seem to have much effect, except that sometimes when I closed them it would run better for a bit. Nothing I did seemed to make it smooth out (or as smooth as a diesel ever sounds:-). Just to see, I checked the bleeder bolt again, and it spewed air. lots of air.
Back to the internet for help again. The general consensus seemed to point to there’s a leak in my incoming line somewhere. the leak doesn’t have to be big enough to let fuel out in order to let air in. So I took the line off at the tank, and put 15 psi air to it while spraying down all the connections with soapy water. I found two leaks and fixed them, figuring that NOW I could bleed the thing and it would run good again.
Go through the same rigamarole: bleed the bleeder until there’s no air (which seems to take longer each time I do this), and then bleed the injectors. By this time, the engine fires up instantly, so I’m always bleeding the injectors while it’s running. Still runs poorly. still dies if I try to give it throttle.
After reading forums again, it appears that there’s a possibility that the pickup in the fuel tank is allowing air to get in. So I disconnect the fuel line at the tank and put it into a fuel can full of diesel, it’s buried 8 inches into the fuel, so there should be no air. But the same issue occurs, but this time it does somethings strange: when I open the 4th injector, the engine runs worse, like it always does, and then it dies. That’s the first time it’s died at idle. It won’t restart. I checked the bleeder and lots of air came out.
Then I removed the auxiliary fuel filter from the line, in case that was a problem. Same deal, only now the truck won’t start. I changed my process a bit: Crank the engine, check the bleeder, crack each injector, and then check the bleeder again. And I still wind up after a while with bunches of air in the line. the truck now runs for a second and then dies.
I’m at a loss. Do I need to remove the stock filter and re-fill it with diesel? Am I introducing air when I crack the injectors open? I rechecked the lines with soapy water and pressure, and there are no leaks that I can find.
Any help would be appreciated.
#2
11-30-2013, 07:05 PM
Update:
Today I changed the stock filter and replaced the O-rings.
Tried it again. Fuel line going into a 5 gal can. all connections triple checked and tightened. Primed with the priming handle until no air came out the bleeder. Attempted to use the starter with the first 3 injectors cracked open. Air bubbles came out that. It did eventually start for a few moments. Checked the bleeder after it died and there was air there.
Then my battery died.
It occurred to me to try an experiment: I pumped it up with the priming handle until no air came out. then I closed the bleeder and played with electrical issues for a half hour (oddly enough, the wiring diagram for the 69 dodge is wrong.. or at least doesn't match the wiring on MY 69 dodge.).
Then I opened the bleeder again. And lots of air spewed out.
So, as suspected and suggested on the list, I must still have a leak somewhere.
Does anyone have any clue how I can find WHERE it is? I've already done the pressure with soap bubbles and there's nothing showing up, so I'm at a loss.
Today I changed the stock filter and replaced the O-rings.
Tried it again. Fuel line going into a 5 gal can. all connections triple checked and tightened. Primed with the priming handle until no air came out the bleeder. Attempted to use the starter with the first 3 injectors cracked open. Air bubbles came out that. It did eventually start for a few moments. Checked the bleeder after it died and there was air there.
Then my battery died.
It occurred to me to try an experiment: I pumped it up with the priming handle until no air came out. then I closed the bleeder and played with electrical issues for a half hour (oddly enough, the wiring diagram for the 69 dodge is wrong.. or at least doesn't match the wiring on MY 69 dodge.).
Then I opened the bleeder again. And lots of air spewed out.
So, as suspected and suggested on the list, I must still have a leak somewhere.
Does anyone have any clue how I can find WHERE it is? I've already done the pressure with soap bubbles and there's nothing showing up, so I'm at a loss.
#3
12-02-2013, 02:57 PM
Diesel Fan
I would probably start by running the engine off of a 5 gallon can of fuel and see how it does. You may or may not have air intrusion (although that's what it sounds like) it could also be a lift pump that is aerating the fuel. I've had this problem twice once on a first gen dodge cummins and again on an OM617. The other option is to replace some of the fuel line from the tank to the lift pump with some clear hose so you can watch for bubbles. Either way you are bleeding the system again which you are getting really good at by now! I always crack all six lines and crank the engine. As they start pumping fuel out I snug the lines up. Quick and easy way to do it.
If you do in fact have an air leak the easiest way to find it usually, is to pressurize the tank, that will make a small crack or pin hole in a line leak. I'd bet you've got a lift pump that is having a hard time consistently moving fluid in one direction. Sorta like two steps forward and one step back, this aerates(sp) the fuel and causes it to become air bound.
This advice is worth every penny you paid for it btw...
If you do in fact have an air leak the easiest way to find it usually, is to pressurize the tank, that will make a small crack or pin hole in a line leak. I'd bet you've got a lift pump that is having a hard time consistently moving fluid in one direction. Sorta like two steps forward and one step back, this aerates(sp) the fuel and causes it to become air bound. This advice is worth every penny you paid for it btw...
Last edited by Throttle Jockey; 12-02-2013 at 03:09 PM.
#5
12-14-2013, 12:55 PM
today's update:
Checked the bleeder again, still no air bubbles after a week following the replacement of the lift pump and bleed of the system.
opened up all 6 injectors and cranked it a couple of times.
closed all but the first 3 from the front. Engine fired up and ran very poorly.
#2 injector not producing anything. #1 and #3 began spraying diesel all over the underside of the hood and the rest of the engine bay. closed them off. Engine smoothed out considerably.
closed off #2. no change. opened number 2. it started leaking diesel and bubbles. closed it off again. engine died. would not restart until I repeated the above process.
I figured out that the fuel line to #2 is a very tight fit. undoing the nut is not enough to open it. I have to pull on it a bit to back it off. then foam comes out.
Also, through trial and error, I discover that if I hold that open so the foam is coming out, the engine will run. It idles, and can rev up, just as long as I hold the #2 injector line such that it's not fully tight on the injector so the foam comes out.
Also through trial and error, I discovered that if I have the #1 injector open, and I let the #2 injector close, the #1 injector will stop spraying the inside of the engine bay with diesel. if I hold the #2 injector open, #1 injector sprays diesel.
I closed up all injectors but #2 and let the engine idle for 20 minutes to get good and hot. Temp gauge is not yet hooked up, so I don't know where it was, but it was pretty hot trying to hold that injector line open, and the diesel that was all over the exhaust side of the engine was smoking nicely.
After 20 minutes, I closed the injector, and in about 45 seconds, the engine died again.
At that point, I decided it was once again time to regale folks more knowledgeable than I with the tale and await further advice.
I checked the bleeder again. still no air there.
Thanks
John
Checked the bleeder again, still no air bubbles after a week following the replacement of the lift pump and bleed of the system.
opened up all 6 injectors and cranked it a couple of times.
closed all but the first 3 from the front. Engine fired up and ran very poorly.
#2 injector not producing anything. #1 and #3 began spraying diesel all over the underside of the hood and the rest of the engine bay. closed them off. Engine smoothed out considerably.
closed off #2. no change. opened number 2. it started leaking diesel and bubbles. closed it off again. engine died. would not restart until I repeated the above process.
I figured out that the fuel line to #2 is a very tight fit. undoing the nut is not enough to open it. I have to pull on it a bit to back it off. then foam comes out.
Also, through trial and error, I discover that if I hold that open so the foam is coming out, the engine will run. It idles, and can rev up, just as long as I hold the #2 injector line such that it's not fully tight on the injector so the foam comes out.
Also through trial and error, I discovered that if I have the #1 injector open, and I let the #2 injector close, the #1 injector will stop spraying the inside of the engine bay with diesel. if I hold the #2 injector open, #1 injector sprays diesel.
I closed up all injectors but #2 and let the engine idle for 20 minutes to get good and hot. Temp gauge is not yet hooked up, so I don't know where it was, but it was pretty hot trying to hold that injector line open, and the diesel that was all over the exhaust side of the engine was smoking nicely.
After 20 minutes, I closed the injector, and in about 45 seconds, the engine died again.
At that point, I decided it was once again time to regale folks more knowledgeable than I with the tale and await further advice.
I checked the bleeder again. still no air there.
Thanks
John
#6
12-25-2013, 02:31 PM
update:
Thank you all for your help and advice. Last time I got to play with it, I wound up tapping the number 2 injector with a wrench. Then went through the bleeding process. 6 injectors open, then the first 3, only now the number 2 injector was also spewing diesel everywhere.
closed them all off with it running like crap, revved it up with it running like crap and after about a minute, it smoothed out. After that, it ran like a top for a half hour.
Next week, I'll grease up the driveshaft and see how my ford clutch master is working with my dodge slave. It's REALLY stiff, but if it's functional, I can live with it for now.
Didn't have any time to work on it last weekend because I obtained a 91 dodge w250 parts truck with the dana 60 axles and 6" lift kit springs. It also has the clutch slave and master, if mine don't work, I can hopefully cut out the mounting surface for the dodge master and put it in.
now that it's running, it feels close, but I still have to
swap axles and springs
figure out how I'm going to mate the 69 steering gearbox to the 91 steering knuckle
get u-joints that are 91 dodge on one side and 69 dodge on the other
permanently mount my fuel tank
come up with a fuel filler neck that takes a gas cap
pull out my radiator and fix the leaks in it.
get all the electrical sorted out. still have to find a point in the 69 under hood wiring mess that actually has 12 volts when the starter is cranking. or just wire a starter button for the starter. and headlights and turn signals and gauges would all be nice to have.
modify my grille so it fits.
but it feels a lot closer to driving than it did 3 weeks ago :-)
Thank you all for your help and advice. Last time I got to play with it, I wound up tapping the number 2 injector with a wrench. Then went through the bleeding process. 6 injectors open, then the first 3, only now the number 2 injector was also spewing diesel everywhere.
closed them all off with it running like crap, revved it up with it running like crap and after about a minute, it smoothed out. After that, it ran like a top for a half hour.
Next week, I'll grease up the driveshaft and see how my ford clutch master is working with my dodge slave. It's REALLY stiff, but if it's functional, I can live with it for now.
Didn't have any time to work on it last weekend because I obtained a 91 dodge w250 parts truck with the dana 60 axles and 6" lift kit springs. It also has the clutch slave and master, if mine don't work, I can hopefully cut out the mounting surface for the dodge master and put it in.
now that it's running, it feels close, but I still have to
swap axles and springs
figure out how I'm going to mate the 69 steering gearbox to the 91 steering knuckle
get u-joints that are 91 dodge on one side and 69 dodge on the other
permanently mount my fuel tank
come up with a fuel filler neck that takes a gas cap
pull out my radiator and fix the leaks in it.
get all the electrical sorted out. still have to find a point in the 69 under hood wiring mess that actually has 12 volts when the starter is cranking. or just wire a starter button for the starter. and headlights and turn signals and gauges would all be nice to have.
modify my grille so it fits.
but it feels a lot closer to driving than it did 3 weeks ago :-)
#7
12-30-2013, 07:06 PM
Today's update:
YEEHAW!!
Today I went out, turned the key, hot-wired the starter, and it started right up. Then, for the first time since I've had the truck, it moved under its own power. I drove it around the yard a bit, and then parked it next to the parts truck I picked up last weekend.
Which brings me to my next question, for those of you still reading this thread:
I bought the parts truck because it seems universally known that the dana 44 axles will not hold up long to the cummins. And the springs are not happy. I figured I'd get the parts truck and its springs and then get a lift kit later. As it turns out, the parts truck already has a 6" lift. yay!
So the front springs on the 91 cummins parts truck are 48" long, 2.5" wide and 35" outside to outside. The springs on the 69 dodge are 48" long, 2.5" wide, and 35" outside to outside.
The difference is that on the 91, the shackles are in the front, and on the 69, the shackles are in the back.
According to measurements, and the suspension guys I'd talked to when I thought I was going to have to custom build a lift kit and buy custom built springs for the truck, the 91 cummins springs are centered on the axle, same distance and same weight distribution in front of and behind the axles. measurements show this to be true as well.
Is there any particular reason that I'm not thinking of that I couldn't just turn the springs around?
I've been asked for pics of the truck, so here they are:
http://s903.photobucket.com/user/memrys/library/Mobile%20Uploads
YEEHAW!!
Today I went out, turned the key, hot-wired the starter, and it started right up. Then, for the first time since I've had the truck, it moved under its own power. I drove it around the yard a bit, and then parked it next to the parts truck I picked up last weekend.
Which brings me to my next question, for those of you still reading this thread:
I bought the parts truck because it seems universally known that the dana 44 axles will not hold up long to the cummins. And the springs are not happy. I figured I'd get the parts truck and its springs and then get a lift kit later. As it turns out, the parts truck already has a 6" lift. yay!
So the front springs on the 91 cummins parts truck are 48" long, 2.5" wide and 35" outside to outside. The springs on the 69 dodge are 48" long, 2.5" wide, and 35" outside to outside.
The difference is that on the 91, the shackles are in the front, and on the 69, the shackles are in the back.
According to measurements, and the suspension guys I'd talked to when I thought I was going to have to custom build a lift kit and buy custom built springs for the truck, the 91 cummins springs are centered on the axle, same distance and same weight distribution in front of and behind the axles. measurements show this to be true as well.
Is there any particular reason that I'm not thinking of that I couldn't just turn the springs around?
I've been asked for pics of the truck, so here they are:
http://s903.photobucket.com/user/memrys/library/Mobile%20Uploads
#8
03-19-2014, 10:02 PM
It's been a while since I put anything in this thread, so I thought I'd post an update:
This is what the truck looked like 2 weeks ago. The engine runs, transmission moves, clutch works (but is really stiff. ford master, dodge slave), 1991 Dodge W250 axles under it now with a 6" lift, brakes are put together, awaiting an adjustable drag link, which I hope will be short enough. the original was 12" long.
then I just need to finish a million details, like wiring, actually mounting the fuel tank, making a fuel filler neck, building an exhaust system, etc.
http://s903.photobucket.com/user/memrys/media/Mobile%20Uploads/IMG_1098_zps12886bb1.jpg.html
This is what the truck looked like 2 weeks ago. The engine runs, transmission moves, clutch works (but is really stiff. ford master, dodge slave), 1991 Dodge W250 axles under it now with a 6" lift, brakes are put together, awaiting an adjustable drag link, which I hope will be short enough. the original was 12" long.
then I just need to finish a million details, like wiring, actually mounting the fuel tank, making a fuel filler neck, building an exhaust system, etc.
http://s903.photobucket.com/user/memrys/media/Mobile%20Uploads/IMG_1098_zps12886bb1.jpg.html
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