Hello everyone I'm new to this form, however I have read quite a few posts about the 803a and have quite a bit of diesel experience. The problem I'm having is I replaced a broken injector and now its behaving strange. I have bleed the lines per the tech manual several times and it will eventually start every time. All the low pressure connections are tight and vacuum checked. Ran it yesterday at 75-100 precent load for about 6 hours, now this afternoon went to start it again and same story. Waited 60sec for the prime pump then went to start, it coughed ans sputtered but finally got up to 60hz and sounded normal as before. Before I had an injector issue it lit off almost immediately with only a few seconds of prime pump. Although it's working it doesn't seem quite right, any thoughts on what to do next?
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MEP 803a will not hold high pressure side prime.
- Thread starter lmm2012
- Start date
- 2,628
- 6,038
- 113
- Location
- West greenwich/RI
OEM injector or the $50 Chinese injectors?
What style main electric fuel pump is in it?
All you did was pull the cover and swap that 1 injector, correct?
I don't think the problem is with that 1 cylinder. The machine should still lite off right away even on 3 cyl.
Sounds more like an issue upstream of the metering pumps.
Sounds like a bad electric fuel pump, but I wouldn't expect you to be able to reach 75%-100% load if it was going bad, probably 50% at best.
Have you pulled a low side line etc. to check pump flow / pressure?
The LPW4 doesn't like to run on gravity feed only, you often need a little pressure to get the metering pumps working.
What style main electric fuel pump is in it?
All you did was pull the cover and swap that 1 injector, correct?
I don't think the problem is with that 1 cylinder. The machine should still lite off right away even on 3 cyl.
Sounds more like an issue upstream of the metering pumps.
Sounds like a bad electric fuel pump, but I wouldn't expect you to be able to reach 75%-100% load if it was going bad, probably 50% at best.
Have you pulled a low side line etc. to check pump flow / pressure?
The LPW4 doesn't like to run on gravity feed only, you often need a little pressure to get the metering pumps working.
- OEM Injector
- round style electric pump
-#1 injector had a broken spring so it got replaced, and I pulled the other 3 injectors one at a time to verify they were still good, and they were. After that also verified all the injectors were seated in the fuel rack via freeze plug at #4 and a borescope.
- I haven't checked pressure however it has plenty of fuel flow, I was holding above 75 precent and pushing 100 percent when the oven cycled on and off. Unless meter is wrong?
Once it's going it runs perfect doesn't sound like it's missing or anything, but has a hard time starting and getting to full rpm.
- 2,628
- 6,038
- 113
- Location
- West greenwich/RI
I'd look at the fuel rack and solenoid linkage.
Make sure that when the solenoid pulls in, the lever it attaches to goes full clockwise until it hits the stop.
You can also try manually operating it. Remove the solenoid, linkage should go full clockwise stop.
Try to start it and see if it will fire off immediately.
If so, you will then need to manually rotate the lever counter clockwise to shut it down.
If not also verify the rack itself is moving freely.
Make sure that when the solenoid pulls in, the lever it attaches to goes full clockwise until it hits the stop.
You can also try manually operating it. Remove the solenoid, linkage should go full clockwise stop.
Try to start it and see if it will fire off immediately.
If so, you will then need to manually rotate the lever counter clockwise to shut it down.
If not also verify the rack itself is moving freely.
Everything checks out on the rack and solenoid, tried starting it manually and same result.
I did however before I went to start I opened the 2 vent screws on top of the fuel filter housing and got a good amount of air when I went to prime. It seems like air must be getting in somewhere on the low side but not very quickly.
After its up and running I can stop and restart it without issue. It's when I go to start it after sitting overnight that it struggles, maybe it takes that much time for air to accumulate?
Also I haven't looked yet but is there a bleed screw on the water separator housing? That would be the highest point in the low side.
- 2,628
- 6,038
- 113
- Location
- West greenwich/RI
No bleed screw that I know of, just the drain on the bottom.
I would have to check, but on the older 002/003 machines there is a check valve in the fuel line and the pumps also have internal check valves to prevent fuel from siphoning back to the tank. I don't know off hand if your E7014 has an internal check that could be leaking??
For it to leak back you would also need an entry point for air to get in, which it can through the 3.5mm return line that goes back to the tank.
So in short, I'd check the pump next to see if fuel can flow backwards through it.
I would have to check, but on the older 002/003 machines there is a check valve in the fuel line and the pumps also have internal check valves to prevent fuel from siphoning back to the tank. I don't know off hand if your E7014 has an internal check that could be leaking??
For it to leak back you would also need an entry point for air to get in, which it can through the 3.5mm return line that goes back to the tank.
So in short, I'd check the pump next to see if fuel can flow backwards through it.
Will try that next, thank you
Turns out there is a bleed screw on the water separator housing, you kinda need spaghetti arms to get to it. It's way up top facing inward. Fuel pump check valve seams fine. I swapped the supply and return line and tried to pull fuel with a vacuum pump, didn't get any. I added an inline check valve to the return line just in case. I would know anything until tomorrow after it sits over night. Thanks for your help.
