MEP-003a while the shroud is off?

[Isaac-1]

I had to pull the fan shroud off of my MEP-003a in order to change out 2 of my diesel injectors. The two cylinders on the end closest to the blower were very slow to fire after starting on the other two (5-10 seconds), and would blow white smoke for a couple of minutes, changing out the injectors for a pair of tested used ones has helped, but they are still a little slower to fire off, but at least now the white smoke is gone after only a few seconds, in fact one of the two I did not change now puffs white more than they do. My question is what else should I check in detail (other than a quick once over) while I have the shroud off?

Ike

p.s. I plan to check valve clearance also while things are apart, and I am installing a new starter (old one is marginally weak) along with a spin on oil filter kit.

 

[Triple Jim]

I assume you already checked the glow plugs.

 

[1800 Diesel]

Did you check the pop-off pressure of the ones you put in? If the pressure is set too high or too low, this will affect ignition timing. I know you said they were tested but wanted to confirm that meant more than just a visual (spray function & pattern) test.

Kevin

 

[Isaac-1]

Yes, glow plugs tested good on all.

I bought 4 used injectors off ebay a while back, then picked up a used pop tester cheap, out of the 4, 2 tested Good with good spray pattern and pop off at 1750 psi, 1, tested ok pop off also right on at 1750 psi, but spray pattern a little less than ideal, and one tested bad, pop off at around 1810 psi and squirting after initial spray down to 1500 psi. I also have a basket case Onan DJB and a DJE that I need to pull the injectors out of and test, if I get one or two good ones out of those I may swap the other two on the MEP-003a. The DJB has the same 147-0136 injectors as the MEP-003a and the DJE has compatible ones that are factory set to 2100 psi for the Diesel Kiki injection pump found on the DJE. While we are on to finer details the Injectors I pulled out of the MEP-003a were fairly new looking Yanmar produced injectors, and the ones I installed were older AMBAC built injectors. I also plan to test the 2 I pulled when I get a chance, probably when I test the ones from the DJB, and DJE.

 

[Jimc]

how is the compression? if compression is low but not extremely low then the engine will fire off on the other cylinders and as the eng warms up a little the low cyl will eventually have enough heat to fire off and start kicking in. you can get new nozzles for the injectors if they are a bit sticky or not spraying right. jerry got me all new ones on the last batch i sent him. i assume they came from ambach.

 

[Isaac-1]

I have not ran a compression test yet, mostly because I have misplaced my diesel compression gauge, I know I have one, just don't know where it is hiding. I may try to do a leak down test though

Ike

 

[Triple Jim]

Tell me about it! I was looking for my dial indicator and spark plug hole adapter for about 6 months now and finally found it screwed into the head of a motorcycle engine in my shop. At least I hadn't bought a replacement yet.

 

[ETN550]

You are on the right track. Good clean combustion is the result of crisp spray, timing and heat of compression.

One thing to check that is often not discussed with diesels is the delivery valve on the injection pump. I'm not familiar with the distributor pump on these unit so I cannot offer specific help as to how to disassemble and check. I imagine there is a delivery valve at the pump output where each line connects to the pump. The purpose of the delivery valve is to hold the line pressue just under nozzle opening pressure so the pump does not have to squeeze extra fuel each time and rebuild volume and line pressure before the injector opens. The injectors may test good but a bad delivery valve will cause low fuel output, reduced timing and possible air entry into the nozzle tip. Not saying this is the problem but the delivery valve is often overlooked and it plays an improtant role in the system.

 

[dangier]

Is your 24 vdc charging system up to snuff? Good time to check things out while you have the fan cover off...
David