Another 803 No Start

[StVeronus]

Hi SS,

I have purchased a PU with dual 803's. The first I did oil/fuel/filters/hoses/batteries and it started right up. This unit started and ran in the auction. The second unit was "non-running" as the fuel lines were too rotted. I replaced the lines/oil/filters/batteries and tried to start it. It will crank, but won't start/run. I don't see any exhaust (black/white smoke) out the stack. The gauges all look good, new fuel, the solenoid moves when put to start, I get oil pressure, no dummy lights on panel, and the fuse is good. I have let the pumps go for about 5 minutes and get a decent flow out of the tank return line. I tried cracking the injector pump lines, but don't see fuel shooting out, just a slow seep. This is the same for all 4 injector pumps. I do have flow out of the banjo after the fuel filter housing prior to the injector pumps. I read thru the TM's, but didn't see the procedure for troubleshooting the injector pumps. Any advice?

Cheers,
Ryan

 

[Guyfang]

Wil the fuel cut off solinoid work? When we know that, we will know if it's electric or mechanical.

 

[robertsears1]

I do not own an 803, but I have two 804s and I expect they are similar since they are of the same family. Your symptoms sound like a problem I had although my 804 was runing fine and then it suddenly would not start, not exactly your problem since you haven’t seen this unit run. See if your unit has a magnetic pickup (MPU). If it does, you can get crap sticking to the magnet which then does not allow it to know that the generator head is turning and it does not allow fuel to be pumped by the IP to the injectors. In other words, the blocked or incorrectly positioned MPU makes the unit think you want it shutdown since your symptom of no smoke from the exhaust while cranking sounds exactly like what I had. Check the books about adjusting the MPU. It can also be damaged if someone screwed it in too far and ground off the end with the same symptoms.

Robert

 

[Guyfang]

Robert is correct. Very common problem. That's why you always look at the L4 to see if it works. If it works, it's a fuel /mechanical problem. If it dosn't work, it's an electrical problem, (99.98% of the time).

 

[Bmxenbrett]

You should see a healthy amount of fuel coming from the hard line side of the injection pumps. If you dont you have a fuel delivery problem, fuel rack problem or fuel lift pump problem.

Also if the system was turned over alot with rotted fuel lines the system could be air bound. You may need to bleede the air out of the system. To do this crack all the hard lines at the Inj pump then when you get a good amount of fuel tighten them and then crack the hard lines at the injectors.

 

[StVeronus]

Thanks for the suggestions. Yes, the fuel solenoid does move the full length when in the Start position and stays when moved to Run. It then moves when turned to Off. I will look for the L4/MPU and see what I discover there.

 

[Guyfang]

No need to look at L4. It works. Nor the MPU. If the MPU did not work, the L4 would not move. Having said that, the L4 is something I always pulled, checked, cleaned and PROPERLY reinstalled on almost any gen set I worked on. I just made sense to me to do this simple thing, and never have to worry about it again. You have a fuel delivery problem. Crack the output line at the electric fuel pump. Are you getting GOOD pressure? If not, or your not sure with what "good pressure" means, look up the electric fuel pump test procedure in the -24 manual. Simple test. You need to continue on, through the fuel system, to the Injector pumps. Do not remove the pumps. Or if you do, just do it one at a time. If you get good pressure up to the IP's, and nothing at the Injectors themselves, then you may need to pull the IP's and clean them. Remember, ONE at a TIME. And you have to get them back in right. Take your time. But first, pressure tests.

 

[StVeronus]

I looked in the -24 for the MPU. Before I was going to undo it from the flywheel, I want to make sure I got a Voltage reading at the terminals 3 and 6 of the disconnect switch in the control panel. I'm 99% positive that I found the right location (see pic)
, but I don't get the voltage required (2-3 VAC) when dead cranking. I also checked the working unit and it didn't show the voltage while dead cranking either. So I'm doing something wrong even following basic instructions .

 

[Guyfang]

Here is the short version.

Go to the MPU. Disconect the two wires. Hook up your meter for AC VOLTS and hold the probes to the wires, while someone turns over the gen set with the S1 switch. You want between 2-3 volts AC, and the closer to 3, the better. Try that. Are you working this problem right now?

 

[StVeronus]

Yes sir I am. I will give that a go and see what it turns up.

 

[Guyfang]

OK, I am up a wile longer. Its 21:11. I will keep an eye out for your posts.

 

[StVeronus]

So neither the non-starting PU or the working PU show voltage at the MPU when controlled by S1. The working unit fired up when testing and it still showed no voltage while running. I'm confused. Just making sure, this is the MPU, correct?

 

[Guyfang]

Yes, that's the MPU. And you did measure at the two wires going into the MPU? MPU means Magnetic Pick up. And yes, I had someone measure the two wires going into the control panel. We liked to never got that straight! And you have to get AC voltage on those two wire for the set to start, excite and produce voltage. So if you didn't get that on the working set, you are doing something wrong.

 

[StVeronus]

I did measure the wires coming out of the MPU. I made sure the meter was working as well by testing the house mains voltage and it showed 120v. Not sure why these are both showing no voltage. I will pull and inspect just to see. Then it is a wrap for today's session.

 

[Guyfang]

OK, and you should get the voltage with S10 also. I forgot to say that. The MPU produces its own voltage, so its not dependent on the set. And its only in extream cases that the MPU will keep the set from starting. Mostly you find the starter grinding, or no excitation, as the problem.

 

[jamawieb]

Hi SS,

I have purchased a PU with dual 803's. The first I did oil/fuel/filters/hoses/batteries and it started right up. This unit started and ran in the auction. The second unit was "non-running" as the fuel lines were too rotted. I replaced the lines/oil/filters/batteries and tried to start it. It will crank, but won't start/run. I don't see any exhaust (black/white smoke) out the stack. The gauges all look good, new fuel, the solenoid moves when put to start, I get oil pressure, no dummy lights on panel, and the fuse is good. I have let the pumps go for about 5 minutes and get a decent flow out of the tank return line. I tried cracking the injector pump lines, but don't see fuel shooting out, just a slow seep. This is the same for all 4 injector pumps. I do have flow out of the banjo after the fuel filter housing prior to the injector pumps. I read thru the TM's, but didn't see the procedure for troubleshooting the injector pumps. Any advice?

Cheers,
Ryan

Sounds like the injector pumps are gummed up. If you take the hard lines off and you're not getting a good shot of fuel out, than that's the problem. Leave the pumps in place and take the top of the pump off (it takes a 3/4 wrench) but be careful because there is a spring and washer in there. Then spray carb cleaner into the pump and let it sit. Turn the motor over with the dead crank and spray carb cleaner in it again. Hopefully that will loosen them up and you can put them back together and it will run. The plunger inside the pump gets stuck and will not push fuel to the injectors.