LTA10 Cummins from about 1990 in an '87 International has developed an intermittent problem. Engine starts and runs very well, cold or hot. Occasionally it will cut off if you depress the accelerator too far too fast. If you veeery slowly press the pedal, it will go all the way to the floor and engine will perform fine. If it cuts off, it is just like you turned the switch off, no stumble no hesitation, dead. The thing that makes me think it is a pump problem is that it will not restart until the crankshaft stops turning completely. 9 times out of ten, as soon as the engine stops turning, hit the starter button and it starts immediately. No spinning, no hesitation, running in half a revolution. Sometimes, it will not restart, and the fuel filter will be only half full, but that has only happened twice. Both times, I filled it up and it started very quickly. When this problem starts. it will cut off anywhere from 3-15 times if you hit it too hard, then it will straighten up and be fine for ten days, or a week, or 2 days. I will get and post the engine numbers when I get back, I thought I had a pic of the tag. This is a fertilizer truck, so it gets abused severely compared to most trucks.
Will be something other than pump, sounds as two or MORE issues, sucking air with filter not full and the rapid shut down something to do with fuel shut down solenoid atop the pump. First off fix the sucking air, these trucks tended to use standpipe feed fuel tanks, if a bottom draw replace the lines as the one feeding the pump has a inleakage issue. As to the solenoid, simple check, screw the Manual Override screw full in and start the engine, without unscrewing this it will Not electrically shut off, perform the hard throttle test again.
Fuel shut off solenoid
Very nice thing about the Cummins PT pump with the manual over ride screw on the solenoid quick twist of the screw and you eliminate an electrical problem, or more correctly over ride the problem. Just remember you can't shut off the engine until you back that screw back out!
Being a fertilizer truck, I wouldn't discount the possibility of corroded grounds between the starter, block, frame and the cab. Seen a lot of weird stuff like that on those trucks.
Had forgot that life lesson or that cell burnt away, used to work on Hwy 79 Farm Center Lime and fertilizer trucks, is where I learned to weld rust and how to fish thru bird nest wiring nightmares. When in doubt they would just run a new wire, while leaving the old one in place.
Yep, years back had a Terragator with a triple nickle doing the same kind of stuff. Screwed in the knob and no problems, then the air conditioning started acting up, that was when they finally let me find the real problem. With the battery cables connected to the starter it would crank easy, but the rest of the grounds were a mess.
That's the best way to wire. Eliminate all the potential problems.
Now that's funny!!
Had a similar issue with my Jeep Grand Cherokee last year . Ran fine in forward gears but put it in reverse and engine would die . Turned out to be a loose ground strap on the engine block .
Dang Mitch ! You could lay field tile behind the spreader truck & get paid for drainage as well . Very wet in my neck of the woods . Ground is saturated & looks to be a slow start for planting .
Had an N14 come in 2 weeks ago doing all sorts of weird stuff, had one bad ECM feed fuseholder. Both were hidden down below the starter in the grease and grime, not quite as bad as some Kenworths that hide them on top of the trans where you can't reach them from the front or back.
The fuel filter won't be clear full on a Cummins with a PT pump. If it is electrical it should be getting worse as time goes by, but those models of International had a very poor fuse box and wire terminals. When I worked for a Ag outfit before this job I had eleven of that series with rotted fuse boxes and electrical issues. If the windshield leaks water it will run down and soak the fuse box and connections.
Don't forget about the pulse damper. A weak or cracked disc will cause all kinds of shenanigans.
Its been wet by us too. That stuck picture looks like it wasn't getting any better the whole way coming out. Just sunk down and stayed down.
OF COURSE, I left out vital info in my first post. I screwed in the override screw the second time it messed up, because my first thought was electrical also. It makes no difference, and, unless I am really missing something, totally eliminates all electrical causes. The really strange thing about all this to me is that when it occurs at highway speed, it will not restart while the crankshaft is turning, but will restart immediately if you mash the clutch and let the engine stop for a fraction of a second before hitting the starter button. This problem only occurs with sudden hard acceleration, and I wonder if it could be an AFC problem? The stuck truck photos were actually last year, and the truck drove to where you see it, making those canals by itself. Those trucks will keep moving through some amazingly bad terrain, and then refuse to climb out. Those pics were taken as I was extending the backhoe boom, before we hooked it up. This year it's only been pulled once, because from the hurricanes of September until March, it simply stayed too wet to think about doing anything, then dried up.
What about the pulse damper? can it be replaced on the engine? If I can't find this problem soon, I am going to pull this pump off of this L10-300 and replace it with one off of an L10-270 that I have and see if the problem goes away. I hate to do that without finding the problem, because I could fix an air leak while changing pumps and never know. I know that when the fuel level gets low, just before it runs out, these truck will do strange things as they begin to pick up air.
Its serviceable in chassis. I lifted this image off the internet so you can see what I'm describing. 2 screws hold it together, 2 longer screws secure to pump. So, it will start every time, as long as you allow the crank to come to a stop. Correct? You also mentioned the filter getting drawn down. This makes me believe you have a supply issue. As DMiller already pointed out, you've got to verify supply beginning to end. Do you have plastic fuel lines or aeroquip? Aeroquip are known to break down with age and allow either flappers in the line or air intrusion through the hose itself. Many mfrs got away from braided hose and went with plastic air brake hose to eliminate this. Hope this helps, good luck
It certainly sounds as if its a supply problem.. cuz just as soon as the crank stops turning, creating a vacuum on the inlet line, it'll start.. It sounds as if the inlet line has collapsed internally.?? 1 way to verify is to put a vacuum gauge on the inlet . I don't work on PT pumps but I've seen THAT happen to 100's of'm that came into the shop. It happened so often that the PT guy rigged up a hose w/ a vac. gauge that he just unscrewed the inlet hose on the engine & put "his rig" between the pump inlet fitting & inlet hose.. A 10 minute diagnosis & 100.00 worth of hose & the customer was ridin' down the road.. btw> anything over 4" of vac & u gotta a restriction.
International started using nylon air brake tubing in the late 70's, so there is a possibility a short braided hose from frame to pump and return. Or it's all nylon right to pump.
The fact that you try to accelerate slowly the engine will slowly pick up tells me something internal in the pump or drive through the pump. I remember some tears ago one that had similar symptoms and the pump shop found issues with the something in the drive system inside the pump. Now that's only been 30 years ago and I can't remember the total details.
Even if you don't have rubber fuel line, you could have a floater, or some small junk trapped in a fitting somewhere, or a kinked line.
Worst cases of truck intermittent foul ups was a old Pete COE with a 6V92 in it, would drive fine a LONG time then just die, owner had been to FIVE shops along his route, towed three times and none had found the issue, drained tanks, found the pop caps of seven HEET bottle and the aluminum seals laying in the tank bottoms, he had used the fill neck for a bottle opener when could not finger them off(arthritic) did not see them or the seal foils go in either. Next up a Brand New Union Electric tandem Digger Derrick Utility truck, fresh from ALTEC industries, would run a day or so then could not keep running, had it to their OWN ST. louis shop to no avail, I get stuck with it as a tow in. First to note fuel filters sucked almost dry, suspected blockage but 1987 C8000 Ford with 3208 had nylon fuel lines little chance for skive, fuel less than 1/4 full shine flashlight into Custom ALTEC fuel tank, a absolute mess of welding slag and trash, had not been cleaned prior to placed in service. Lucky with this one had a alternate fuel pump installation plate so could get hands inside and clean out.
Twice I've seen those foil seals cause problems with top draw tanks. One will stay full while the other runs out.
I've had the fuel filler cap tether chain all wadded up on the first elbow out of the standpipe. You wouldn't think chain could get pulled up.
The next time this engine acts up and dies, before restarting blow the dirt away from top of pump. There will be a hex head 1/4" pipe plug on top of pump near the front outer edge. remove it and see if the pump is full of fuel, you might need a mirror to see down that fill port because of the type of truck you have. My problem with a restriction in a fuel line is this engine should not start right away or as soon as engine stops. If it had a restriction it should require some cranking to prime system each time. Had a T800 4 years ago that would shut off intermittently. Checked fuel pressure at filter head it was reading ok after about 20 minutes of running I noticed the fuel pressure go erratic and drop to Zero. Put a fuel hose in a 5 gal bucket of fuel reprimed and ran fine for an hour. Hooked line back up ran under 1 minute pressure dropped it died. Put air back through fuel line you could hear it bubbling in tank. Drained tank removed from truck and found that part of a fuel tank sending unit { about 20" long 1 1/4" wide} piece that fit inside the tube type senders was laying such a way that the suction would pull it against the pick up tube opening. It was fun to remove it {two hours later}. But every time this engine died it was a reprime. CAT That Cummins should at least take some cranking to restart each time if pump was being starved of fuel.
Okay, this problem finally happened often enough and consistently enough for me to be able to do some troubleshooting. It would do it two or three times, then not at all for a few days, then two or three times. Usually, it would restart immediately, but not always. Day before yesterday, it did it 15 or 20 times, and NOT WHILE BLOCKING THE HIGHWAY! It would die when you tapped the throttle, and not restart when you hit the starter. When I screwed in the override screw, it would restart, and run fine. Unscrew the screw, and it would die when you hit the throttle hard and not restart until you screwed the screw in. As long as the screw was in, it wouldn't cut off. As soon as you screw the screw out, it would do fine with everything except a hard tap on the throttle, then it would die and not restart until over ridden. It suddenly straightened up and has been fine since. I did not have a way to measure voltage at the fuel solenoid, but I examined and wiggled all the wires involved and could not come up with any scenario where pressing the throttle hard would cut electrical power, and nothing else would. My current theory is that with the pressure surge the shut off closes. That great video says that the shut off is on the discharge side. I guess I am going to go ahead and change that solenoid and see if it cures it. Now I'm about to start another thread about a pickup I'm probably going to buy with a similar problem.
It may be that you have a weak solenoid coil, I seem to remember a warning in an old 220 Cummins manual advising not to shut the key off while coasting, other wise the engine had to come to a complete stop before the shutdown valve could reopen.
Or a cracked plate.?? Mitch, why the H didn't u call me before I went to Andrews yesterday.!! I have 1 already rebuilt I woulda brought ya.. I have to do another job up there, so hold off on buying 1 if u can.. I'll be there Saturday if my parts come in.. I'll only charge ya my NORMAL delivery fee.. 1.25/mile & 35.00hr/ drive time.. 120miles R/T & 21/2 hrs.. seems reasonable.. Lol
The solenoids can and will quit like that especially at a intersection with fire trucks coming. I think the second reply to this thread said something about the fuel shut off solenoid.
On the pickup, likely a Dodge? with a 5.9 Cummins that will be a external solenoid to a lever if an older engine with a Injection Pump. Totally different scenario, other breeds also complete different animals.
Those solenoids are interesting. Will work great for 40 years then all of the sudden cause ya fits. Do love the fuel screw to get home with.
Umm, you were too subtle. You should have put it in red 7 point type. I saw that, but was thinking electrical, not failure of the solenoid itself. I was thinking hitting the throttle wouldn't cause that. Seriously though, the problem was so intermittent it was nearly impossible to diagnose, until it finally did it more than once or twice.
No joke about the fire truck, had it happen in Moses Lake Wa at 5:30 p.m. I had everyone pissed off til I got the screw turned and the hood shut.
I had my solenoid experience climbing that steep grade out of Kahlotus headed to Devil's Canyon, no momentum, and wasn't going to coast a set of doubles backward. I saw all the electric gauges dip at the same time and knew something shorted out. Tipped the hood and saw the solenoid smoke, yanked the wire and turned the screw, didn't even latch the hood 'til I got onto Devil's Canyon road.
Just a little update. Pumpguy did bring me a new solenoid, and I put off changing it for a few days, because the pump is under the cab. I drove it by turning the screw in for a few days and it got well. I have had absolutely no trouble out of it for almost a year.