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MB. Cat

WD 40 injection pump

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I have a WD-40 Diesel which I have recently restored. I am having problems getting it to run correctly on diesel. It acts like the timing is retarded at slow speeds. Once you move off of idle the smokey exhaust cleans up and it runs good. The injectors were set to pop at 800lbs and the pump timing is per the book. I have the fuel quality (cetaine adjustment) in the max advance position. Could my fuel supply pump pressure be the culprit? The pressure drops at low idle. Any ideas?

I have four of the verticle heads for these engines, all have cracks on at least two of the cylinders. The cracks extend from the injector to the valve seats. The head I am using had two cracks in two cylinders which had been pinned many years earlier. The shop that reworked the head pressure tested it and found no leaks. They said that the cracks were stress from the casting process and once repaired with pins they seldom give any problems.

Thanks

David

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Hi David

I'll try to get to the cause of your problem.

1-Need to know if engine is well wormed up to operating temperature?

2-what color is the smoke?

3-is it smoking on every cylinder or just one?

4-have you done a compression test?

5-when you did the motor, are all valves seated the same depth?

6-did you put all the same cracker valves in the injectors, or are they mixed?

7-when the injection pump was done was it tested for the same psi. output on all plungers?

w'll start with this.

ttyl

John

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Hi David

I'll try to get to the cause of your problem.

1-Need to know if engine is well wormed up to operating temperature?

2-what color is the smoke?

3-is it smoking on every cylinder or just one?

4-have you done a compression test?

5-when you did the motor, are all valves seated the same depth?

6-did you put all the same cracker valves in the injectors, or are they mixed?

7-when the injection pump was done was it tested for the same psi. output on all plungers?

w'll start with this.

ttyl

John

Yes, the smoke is the same whether hot or cold. The engine does not miss, it just smokes on all four cylinders.

The smoke starts after the engine RPM is stable at idle for about 10 seconds. I can raise the rpm above idle for about 5 seconds and the smoke clears. I can then return to idle and it will be clean for about 5 to 10 seconds. The smoke is a light gray color. The only compression test I have done is by feel cranking it manually on diesel. This engine was rebuilt using new sleeves and almost new pistons (flat top with silicone insert). I have another one of these tractors S/N1037, and this tractor has much better compression than its sister tractor which runs perfect. Valve seat depths vary slightly due to not having new parts. The injection delivery valves are 800# and were set as close to 800 as I could get them. They may vary by a pound or so but were very very close. This engine originally had the 400# valves (did not use these as IH upgraded the later serial numbers to 800#) when I tore it down. The injection pump was built from a collection of parts over a 20 plus year period. The plungers and barrels were matched using the best parts and hand lapped and polished using newspaper to achieve the proper clearance. I set the dump valves (bypass valves) at .095 clearance as stamped on the side of the injection pump block. The engine runs smooth and has no smoke at full load or no load except at low idle. I feel the timing is retarded given the cetane adjustment has to be in the full advance position for it to run good.

David

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Hi David: It looks like you have a god understanding of your WD40. You seem to have dne everything by the book. Have you cheked the fuel supply pump pressure? There is a 1/8" pipe thread plug on the back of the pump block cover (beside the return fuel to tank connection). 30 psi is good, but engine should run on 12 psi or more. Sometimes you have to advance the pump timing at the pump coupling. The timing marks are for new machines, and it is necessary to compensate for wear as time goes on. The fact that you have set the running timing adjustment full advance tells me that your pump is not advanced enough. It should run good near the O mark when well warmed up. Let us know how you make out. CardaleBob

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Hi David: It looks like you have a god understanding of your WD40. You seem to have dne everything by the book. Have you cheked the fuel supply pump pressure? There is a 1/8" pipe thread plug on the back of the pump block cover (beside the return fuel to tank connection). 30 psi is good, but engine should run on 12 psi or more. Sometimes you have to advance the pump timing at the pump coupling. The timing marks are for new machines, and it is necessary to compensate for wear as time goes on. The fact that you have set the running timing adjustment full advance tells me that your pump is not advanced enough. It should run good near the O mark when well warmed up. Let us know how you make out. CardaleBob

I have checked the supply pump pressure visually by opening the bleeder valve on top of the filter housing. At RPMs above low idle the pressure is strong, at low idle it just squirts. I will use a pressure gage and take readings from the 1/8 pipe plug and advise. When I overhauled the engine I was fortunate to have almost new timing gears. I disassembled four engines and was able to salvage a good pump drive shaft with excellent key ways. I am certain the drive train is as good as possible. One item I am starting to question is the pump drive flange that attaches to the main pump shaft. I am wondering if it is a mismatch given the pump was assembled from leftover parts from several pump over many years. It could be that this drive flange is off a later style pump and is drilled incorrectly. I am currently running the flange in the most advanced position.

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On the coupling flange is it 3 bolt hole or 4 bolt hole

John

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On the coupling flange is it 3 bolt hole or 4 bolt hole

John

The pump drive flange currently installed is a three bolt. I have a couple of other flanges, one is a four bolt.

Thanks

David

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Hi David: If the 4-bolt flange does not give you enough advance, you can mill out slots between 2 bolt holes, and rely on bolt tension to drive. Note the reference marks on the 2 halves of the coupling, to determine where you have to go. Another way, is to make an offset key, not impossible, and completely hidden for purest police. Good Louck. CardaleBob.

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Hi David: If the 4-bolt flange does not give you enough advance, you can mill out slots between 2 bolt holes, and rely on bolt tension to drive. Note the reference marks on the 2 halves of the coupling, to determine where you have to go. Another way, is to make an offset key, not impossible, and completely hidden for purest police. Good Louck. CardaleBob.

I actually have a flange that is already slotted. I may give that a try.

Thanks

David L. Jones

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I don't know if it's aplicable to your WD40, but some of the blokes in my little vintage club were fooling around with the injection on a WD40 that wasn't running right, and a local fellow who had operated a TD35 for years showed them how to unblock some filter screens on the inside of the injection pump. I wasn't involved with the work, but under the cover that the fuel presurising pump is mounted in there is 4 screen filters that stop the crud from entering the elements. Vince recons those screens block up giving a lot of trouble, but cleaning them is aparently not all that hard. I will be seeing the blokes involved tommoro, and will try and remember to ask what you have to do.

Anyone have an inkling of whether this may be the problem ?

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Hi Grey power

I don't think the screens you talk about are the cause of the problem.The pump has been all gone through and these screens would have been cleaned. It would appear at this point that it is a timing thing, as other things have been verified as being in good working order. Head preasure in the pump has not been verified yet. What I see showing up here is timing problem, it may be caused by the coupler, but there is also other things in this pump that could cause this. One has to track each one down in progession & either eliminate/fix the problems as we go through the injection system.

David

the pump you picture on this engine would appear to be a later style pump, it would therefore need the 4 hole coupler that came with this pump originally. If there is a lot of wear in the timing gears or within the pump itself you may need to use the coupler that you have the open slot in to gain a we bit more advance on your injection. If this dosn't corect the problem we may need to check the sector gear meash.

ttyl

John

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Yes, that is the pump, it is a 20 year collection of parts which I assembled. Everything in the pump appears to be in very good condition. All engine timing gears have just a few hours on them and the pump drive shaft bearings were new. I have attached a picture with a limited view of the gears, but you get the idea. I suspect you are correct about the four bolt adapter. I am going to check the pump pressure, install the four bolt adapter, and install a new timing coupling spacer (fiber coupler 31439DB). I hope to have this completed this weekend, I will post the results.

Thanks again for your assistance.

David

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Here is a picture of the new coupler. It is amazing that you can still buy any new parts for these machines.

David

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Well, here is the latest progress. I removed the pump and checked the pump drive flange. It was the four bolt version. I installed the new pump drive coupler which eliminated 1/8 inch of slack in the drive coupling. Set the flywheel timing mark to SI and aligned the pump SI mark which matched perfectly with the center holes on the drive adapter. Bled the system and started it. I no longer have to run the advance in the full position, I can back it off to 5/8 advance. The engine runs clean and perfect as long as I am above idle. However when I return the engine to idle for a few seconds it starts to run lazy and smoky like timing is retarded. I wanted to check my fuel pressure, however I did not have the proper fittings to adapt my gage. I will try and get the proper fittings tomorrow and test the pressure.

David

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David

It's odd that it smokes on all four cylinders, usually it will smoke on one or two and that can be corrected by adjusting the setting on the fuel metering valves

Another thing you should check out is find out what the cetane # is on the diesel fuel you are using. For that engine it should be 45-50.

You could also try a cetane additive to increase your cetane #.

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I checked the fuel pressure, low idle was 5 PSI, high idle was 15 PSI. I opened the pump and was planning on removing one shim, however I decided to replace the gears to see what difference that made. I was afraid that removing the shim would allow the pump to lock up. With the replacement gears installed I started it up. At low idle I had 0 PSI, high idle was 5 PSI. I then removed the shim and tried again. Still had the same results. Interestingly it runs the same at 0 PSI as it did at 5 PSI. I then reinstalled the original gears with shims removed. Presto, I had 18 to 19 PSI at idle and 27 PSI slightly above idle through full RPM. It is clear that the regulator is limiting the pressure to 27 PSI. I thought about shimming the spring but decided to let well enough alone. The tractor runs perfect best I can tell. At 0 advance it is little smoky at full throttle and seems a little rough. It runs best about 1/2 way between neutral and full advance. At full advance it pings at idle. It will now idle without smoke and runs smooth at all speeds.

Thanks.

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MB. Cat,

You had indicated earlier in your post that these IH engines can be timed by watching the exhaust. What should I be looking for when fine tuning the timing?

Thanks

David

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I checked the fuel pressure, low idle was 5 PSI, high idle was 15 PSI. I opened the pump and was planning on removing one shim, however I decided to replace the gears to see what difference that made. I was afraid that removing the shim would allow the pump to lock up. With the replacement gears installed I started it up. At low idle I had 0 PSI, high idle was 5 PSI. I then removed the shim and tried again. Still had the same results. Interestingly it runs the same at 0 PSI as it did at 5 PSI. I then reinstalled the original gears with shims removed. Presto, I had 18 to 19 PSI at idle and 27 PSI slightly above idle through full RPM. It is clear that the regulator is limiting the pressure to 27 PSI. I thought about shimming the spring but decided to let well enough alone. The tractor runs perfect best I can tell. At 0 advance it is little smoky at full throttle and seems a little rough. It runs best about 1/2 way between neutral and full advance. At full advance it pings at idle. It will now idle without smoke and runs smooth at all speeds.

Thanks.

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MB. Cat,

You had indicated earlier in your post that these IH engines can be timed by watching the exhaust. What should I be looking for when fine tuning the timing?

Thanks

David

David, I think this what you are looking for.

On the setting of timing by exhaust;

And i hesitate to post this because some maynot understand what i am trying to say. I would far rather show someone on engine running than try to explain here. Especially when i can only type 5 words a minute, this post will take me about an hour to type out.

I would doubt that I can explain it well enough that you can understand.

But I will give it a try, maybe some will get it.

First off we are referring to an engine that is in good operating condition. Not one with bad valves, worn rings ,or cracked head. One that we know that the injection system is in good condition and functioning correctly,

also new present day clean fuel with no additives, etc.

1-Set timing mark on fuel pump drive gear on the 0 mark.

2-Start engine and warm up; switch to diesel operation.

3-Warn the engine up until the coolant temp. is in the green zone.

4-Run engine at high idle, after about 15 sec.; observe exhaust smoke;

A-if exhaust has a lot of continious white smoke; engine is retarded to much.

B-if exhaust is just a light haze with no white puffs of smoke; engine is advanced to much.

5- As to what you find in 4; either advance or retard ½ mark at a time on the timing gear, until you get just a few white puffs, this is the point atwhich that engine will preform best.

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I know that is on old post, but I will ask here...

Where does one find parts for a McCormick-Deering WD-40 injection pump (model PT-40, I think) ?

We have a man, here in Australia, who is restoring a WD-40 and he is chasing parts and technical assistance with the fuel injection pump.

Is there a workshop in the States or anywhere that still services these very old style injection pumps?

Regards from Michael H. B) Australia.

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Another bump to this great old thread, my tame mechanic is going to look into what is awry with my TD35 fuel pump (seems one cylinder is loathe to operate all the time) and this thread has a wealth of knowledge that might come in handy! :) The talk about the exhaust coloring is interesting too, hopefully mine stops blowing so much white after we're back on all four.

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