Tunnel drive performance issue

excuse me the waste gate is not the power valve and if both power valves have been turned to minimum because say the engines were used for light load deliveries in a city or in a learner driver car then they both will be the same . If there is not enough fuel to produce the power required they they will not reach the revs expected even though they do it at no load . what if there is a hole in the power valve diaphragms ...do we know ??

First rule ...test dont guess ...do we know the present boost pressure and do we know the power valve settings ...as this thing is super economical a minimum setting could explain the lack of power ....like I said petrol heads should not pontificate on diesel issues ....

 

Sorry Pistnbroke, I appreciate your input but was distracted elsewhere.
I should have better kept the whole project in one thread, but at the time I thought that most people are only interested in parts of it, so I split it up in marinizing, controls, tunnel drives etc. Sometimes even I have problems locating some parts on this forum.

I removed the shock absorbers from the pumps because the electronic controls make no sudden moves. And I took off the EGR-valve and closed the hole with a lid and gasket.
When I received the engines all hoses and cables were sheared off with a bolt cutter, so there were no VW fuel filters. They connect to both in- and output hoses and have a small plastic valve mounted on top. The manual says that below a 19 C. fuel is returned to the filter and above 30 C it is returned to the tank. I made new plumbing and connected the return to the tank only. Did I make a mistake there?

 

Aha, pistnbroke, you meant what we here call the fuel stop adjustment, then I'm with you!

CDK: your plumbing is ok. For fuel adjustment: look at your left pic. Just below where the blue (?) nylon tube disappears behind a bracket at the pump head side the fuel stop is found, pointing axially same way as the pressure valves. It should be covered by a plastic cover and have a jamnut plus a steel collar locked with a small tack weld. If the locking devices are intact, don't bother with the pumps as such.

Like p-and-b said, wait for your manometers, test and avoid guesswork. Btw, if you are very eager to test, use a transparent plastic hose for an U-tube manometer. We expect something like 0.4 bars, that is 4 meters of water column. If that's too high for your ladder....... (and there is no mercury around any more), wind the tube to a series U-tube with a slob of water in each turn. Say three turns, radius a meter or so. Total pressure is the cumulative sum of individual columns!

Also, use an U-tube mano for reading the xh back pressure. Drill a 4 mm hole in the rubber hose just after its connection to turbine outlet (actual dia will be smaller due to rubber elaticity, which is the point). Use a small metal tube as insert (the little brass plug used for pumping a football is perfect!) and connect to plastic tubing. Preferably, there should not be more than 0.5 m watercolumn back pressure. When finished, screw a selftapping SS plate screw into the hole and that's it!

 

fuel stop adjustment ..what planet are you on....power valve is a power valve ....get with the programme ......???
Lets get back to the facts CDK .....tom dick and harry say this is a turbo diesel ..is that right ? So have you checked the boost pressure ? if you dont have enough boost pressure you make smoke .but greater boost does not give your greater power ...you dont burn air you burn fuel .....if you have a photo of the waste gate and its linkage/actuator then thats a start .....also follow the pipe from the wate gate actuator to the injection pump and show me both ends ...
checking out the engines costs nothing and will only take you 1 hour once I can see the detail.

 

As much as I like your contributions "kaputt engine" here I must contradict. There is no "power valve" on a Diesel engine. Can you describe what you are referring to?

Regards
Richard

 

there may be some difference between american and european techonology ..true there is no power valve on the engine its on the injection pump ..CDK is using old pre electronics technology which I know about .......petrol heads keep clear diesel technology rules ..its up to CDK if he wants to check out his diesels for turbo pressure and fueling I will help him .
When I was employed I was paid as a consultant to major european motor manufactureres ..if you want informaton I will send you my pay pal details ...CDK is a freebee because he is in big trouble ....

 

Not sure mate to whom the "petrol heads" was adressed, but it could´nt be baeckmo or me. The fuel stop maybe called power valve by some "tuners" and DIYers, but I cannot find another adjustment to get a direct influence on power.
And have´nt seen major differences in US or EU engines, but, of course in terminology.
Thanks for the Pay Pal offer, but installing some 140 engines p.a. I get my info for free. (well not really, usually the engines are paid)

 

You'll find the picture here:
http://www.boatdesign.net/forums/diy-marinizing/marinizing-vw-turbodiesel-engines-19118.html

 

I guess pistnbroke is talking about the "Kraftstoffmengenschraube", ie the "fuel-amount-screw" to translate it directly. There were never any "power valves" in the Bosch documentation used on the planet where I met with these pumps. "Fuel-stop condition" is a term used in the marine industry to describe engine operation at full load condition, but with speed below the max allowed by the rpm regulator. Just like other trades, marine engineering has its nomenclature to prevent misunderstandings.

And, to be correct, the Kraftstoffmengenschraube is not a valve, it is preloading a system of springs and levers determining the maximum fuel volume to be injected each stroke! The only VALVE available for adjustment on the VE-pump would be the housing pressure valve, situated on top of the pump close to the fuel inlet. So, let's get back to CDK's engine installation!

 

What's in a name? He probably means the capped screw in the center of the high pressure part. That one compresses the spring controlling the basic injection amount for all rpm and loads. The injection curve is limited externally by the two long adjustment screws on the top. On my pumps there are even 4 of them, the other two may be for the limit settings of the starting device.

 

have a nice day

I await with interest the soluton to your problem .....

 

Here are a few confirmed things:
a) VW Transporter 1.9td ABL ecodiesel in fact has no manifold pressure adjustment in its injection pump. (vagcat.com) I think they rely on full load adjustment and torque control adjustments for keeping the amout of injected fuel in control. The original installation should have its full load adjustment on the safe side and the screw sealed.
b) VE pump should have idle, max speed and full load adjustment screws. Wonder what the 4th one is, is it the topmost screw in the pictures above, seemingly unrelated to anything? Vagcat does not show such screw in its illustrations.
c) VE pump does not require a separate transfer pump. Perhaps there are some requirements concerning fuel lines and tank installation, but who knows... Atleast the Transporter does not have one. (Vagcat)

That seemed to be a common ecodiesel "tune up" to open the full load adjustment a bit. I understood that you have the German Bosch manuals, but here is some illustrative reading in English for anyone interested:
http://www.dieselbookmarks.com/bombers/VEPump.pdf

 

CDK
No magic here just a problem that needs some attention to detail and data verification.

The demand on the prop is physically limited at a given rpm.

1. Do you have independent means to confirm the speed of the prop shafts. This is the most important aspect. It would be best to have a calibrated tachometer and place a reflective strip on the shaft. This overcomes any issue with engine tachometer and gearbox ratio. If you do not have one you can get a reasonable one off Ebay for around USD40:
http://cgi.ebay.com.au/2-in-1-Digit....c0.m14&_trkparms=65:1|66:2|39:1|293:1|294:50

2. Can you accurately check the speed. The best way is with a GPS in a current free area. If you cannot be sure you are away from a current then do the test in both directions. You can get a GPS for less than USD100 these days if you do not have one. A car one will do fine. You just want to confirm speed against a reliable reference.

3. Can you check the prop markings for their diameter and pitch. As an independent check on these measure the prop diameter. Also measure the angle of the blade relative to the shaft at 75% of the maximum radius.

This will verify the data used for the power demand. Once this is confirmed we can get back to the engines.

There is nothing that I have seen in any of the data supplied so far that indicates your tunnels are not working well. To the contrary, the fact that the speed dropped when you improved the inlet flow indicates that the props are now getting better flow.

If the prop data previously supplied is accurate they should have a torque demand of 120Nm or 60Nm at the engine shaft. The engines are rated at 150Nm/2400rpm. So at worst about twice the prop demand at 2100rpm.

You should be able to confirm the operation of the manifold pressure compensator (LDA) by removing the boost hose when the motor is lugged down at full throttle. If it does not go any slower when this is open you know you have a problem here. However this should only improve torque by 20 to 30% not the 100% shortfall there seems to be.

I will be much happier about the fuel supply in the lugged down condition when you confirm copious amounts of black smoke in the exhaust.


Rick W.

 

You could probably measure propeller shaft speed with a bicycle computer - they are pretty robust and adaptable and inexpensive for what they can provide. I have a Sigma BC800 that I really like - have used it on my bicycle, motorcycle and truck to get accurate speeds.

For a cheap backup tachometer, try a sirometer. They can often be had for 15-20 USD at small engine shops or on ebay.

Once you get the power delivery sorted out, all of the fine-tuning will be in the props. Good props should reduce your aeration problems.

 

You need rmpsetup.exe from the internet and a laptop. Takes some fiddling with the upper/lower limit and conversion factor, but then you get readings with +/- 1 rpm accuracy. Works with anything that makes noise, from kitchen mixer to aircraft prop.