Timing and injector settings on marinized VW 1.6 diesel

[Ashley5031]

Hi everyone,

My name s Ashley, I am English and live in Rio de Janeiro. My problem is the diesel on my 35 ft Bruce Roberts ketch. I have overahauled the whole boat since buying it in November, but have yet to sail in her because of problems with the diesel engine. I started an inquiry thread on

http://www.boatdesign.net/forums/diy-ma ... 155-4.html

CDK says I need special tools to set the timing belt, plus also he says I need to replace the "heat shield discs"

When I took the cylinder head off and reconditioned it, I also took the injectors apart to clean them. I realize now that this may have been a mistake.

When the engine is running, the timing having been set by eye by the mechanic helping me, number 4 injector is running hot , 100 degrees C, and the engine started to race.

Firstly, to identify the heat shield discs, I need to indentify them...what are they made of and what do they look like?

What adjustments, if any, do I need to make to the injectors aother than merely tightening them up?

CDK says I need tools to set the timing correctly. He is probably right, but the mechanic showed me that if the groove on the valve cam rod is horizontal, the marks on the injector pump are lined up, with the mark on the pulley at the end of the main drive shaft in the most vertical position, then this is the right setting.

When we set the timing, two teeth back and the drive shaft would no longer turn because it was fouling on the valves. So I am thinking of advancing it one more tooth, because the engine is very hard to turn over.

Aside from this, if you look at the inquiry thread on the other site, you will see that my main problem is that the engine continues to overheat. That is to say that the heat alarm goes off, although the heat sensor when measured with an IR thermometer, actually shows a normal temperature of 85 c or so.

Any suggestions?

[81caddyGuy]

I read on the other site about what cdk said. uploading pictures of your small cooling circuit would be very helpfull to verify correct routing. I am sure there is a place in rio to get the heat shields for the injectors but the host of this forum sells these vw parts if you contact him @ jack@vwdieselparts.com he should be able to source you some heatshields and the correct tools to set the timing. I will say i have never heard of a four toothe tollerance for timing belt settings. If the crank it at top dead center you pin the injector pump line up the mark on top of the pump to the bracket (this will put you very close to correct timing) you have to loosen the cam sprocket from the cam (no keyway tapered fit) lock the slot in the back of the cam paralelle to the head ( i use a flat piece of steel) tighten the timing belt then retighten the cam sprocket, un pin the pump and it will start if everyhting else in in working order. I have on hand a set of heat shields if you get me a mailing address to you i will see how much it will cost to mail them but i do not know if customs will hold them with a release fee.

[Vincent Waldon]

Some thoughts:

To answer one of your questions on your other thread.... the heat shields are the small steel disks that go between the head and the injectors, and they are single-use only because they deform as you torque the injector down to form a perfect seal. Once deformed they can't be used again.

If you have localized overheating there's a good chance an injector is misfiring... moving injectors around is one way to localize it, but you could also pull the injectors out and have them pop-tested at a diesel shop... probably the best way, and you already know you need to replace the heat shields anyways.

Finally, I'd really recommend timing the engine properly, from scratch, by the numbers. You can't eyeball them... jigs are needed to hold everything in perfect alignment. The Bentley service manual has the full proceedure and there are a number of HOW-TOs on the web... including this one:

http://vincewaldon.com/index.php?option ... &Itemid=28

Most of the jigs can be fabbed up. Given that these are interference engines it's critical to get everything aligned properly. Poor timing can also cause engine overheating problems as well.

[82vdub]

CDK says I need tools to set the timing correctly. He is probably right, but the mechanic showed me that if the groove on the valve cam rod is horizontal, the marks on the injector pump are lined up, with the mark on the pulley at the end of the main drive shaft in the most vertical position, then this is the right setting.

By aligning all the marks up and assembling the timing belt on the engine, this sets the static timing, or initial timing of the engine. To properly time the injector pump to the top dead center (TDC) crank position, you need a dial gauge that's inserted into the injector pump (IP). However, setting actual timing can be done by ear if you feel so inclined to do so.

When we set the timing, two teeth back and the drive shaft would no longer turn because it was fouling on the valves. So I am thinking of advancing it one more tooth, because the engine is very hard to turn over.

Unless the installation of the timing belt was not done properly, or there is slight out of spec marks for the TDC position on the crank, there should not be any need to slip the timing belt a tooth or more. The bracket that holds the IP to the engine is slotted and allows adjustment of the injector pump. Plus, if you are slipping the belt a tooth, where are you slipping it's position? IF you are slipping the belt a tooth at the crankshaft, you are moving both the injector pump (which controls when the engine fires) and the timing of the valves. If you ever need to slip the timing belt a tooth, it should be typically done on the IP pully. The position of the valves to the crankshaft timing is very critical, as it sounds you are finding out. I would also suggest that anytime you do anything with the timing belt, rotate the engine at least two complete revolutions with a wrench on the crankshaft bolt before you use the starter to turn the engine over. If you messed the timing up, you will be able to feel the valves hitting the pisstons and you won't damage anything. Using the key you can bend valves.

[Quantum-man]

Ashley, if you have heatshields like the one's shown on your link, then as much as I don't like to disagree with others, YOU CAN REUSE the heatshields. A guy called Sharkey used to reuse them 10 fold, but I'm only up to 3x at the, moment, with absolutely no leaks.

However you must reset them with a small [3/8" ish] ball bearing on the concave underside and a M12 nut on the other and a pair of 'Mole grips to crimp them. If you can, order some reserve new ones. As the injectors are retightened you will feel the shields re deform, as they seal. If bubbling up the threads persists, leave for a day or so then replace. If you rest a used shield on an injector you will see it is making contact around the circumference of the shield. A properly reshaped injector shield will only touch the nozzle in the middle.

[Quantum-man]

Ashley,
Traciing your link thread back to it's origins, I have a few suggestions. What procedure did you follow to torque the head down on the new gasket? With a torque wrench, check each head bolt for tightness by undoing each one 45 degrees and retorqeing 90 degrees Any loose?
If overheting persists then does bubbling commense in the coolant almost immediately?
If so your head is either cracked or gasket failing.

[hagar]

Yiks

hagar.

[hagar]

CDK Said : " There are guys who can adjust VW diesel timing in the dark, without tools, by just listening to the engine. I am not one of them"

hagar is one of them..

hagar.

[hagar]

Ashley : November ? what year ? CDK is technically correct . I never use anything but socket set.

And "Us TUNERS" do more than listening. .. The forum of Jacks and Dan;s are loaded with "TUNERS"

Mark Shepherd "Quantum-man" is a good one AH he is better than good. and he speaks the Queens English.

I have lots of suggestions .

Injectors ? I never clean them , far better to simply replace Nozzles. .( I use 193 on all my VW Diesels)

Is that a "REAL" Marine diesel ? or a converted Car engine ? Or an industrial ?

see Us forum guys ned to know a lot of thing.s .

stay Tuned

hagar.

[Ashley5031]

Hi Hagar,

Have a look at the thread on this other site:

http://www.boatdesign.net/forums/diy-ma ... 155-5.html

This is a marine conversion by Retipar of Curitiba in Brazil. I have been battling with this engine since November last year when I bought the boat and did a refit.

Could you explain the tuning procedure to me using the fuel injection pump? I received this explanation but did not fully understand it...


From " Joat.".....

this is all with the belt off .

to set timing manually ...

remove valve cover , both lobes of #1 should point UP and the slot at the other end should be level with the engine head ( put a file or door hing in there and use 2 flat screwdrivers to spread the hinge equally ....

then use a locking pin in the IP sprocket ( about 9/16" bolt hole) and pump to lock the pump/gear in place. (approximate timing for starting) ... loosen the 4 bolts holding the IP.

get the crankshaft at TDC for #1 cyl ( look for the flywheel marks )



remove the camshaft pulley ( or just loosen , so it spins freely ... no key in the key way.

install belt , and tension with idler pulley. TIGHTEN cam bolt. remove locking pin from IP , then rotate the engine over by hand a few times to make sure the valves don't touch the pistons .


the engine should start and run but the timing of the Injection pump may be way off ..... make a reference mark between the IP and the belt guard.....loosen the 4 IP bolts again and start the engine....now slowly push the IP towards the head if the engine when its running.... listen for the sound of marbles hitting a dinner plate. When you hear them , pull the pump away from the head until the sound goes away. make another mark.... stop the engine, check that the new marks line up and tighten the 4 IP bolts . .....


Surely if I loosen the 4 bolts holding the injection pump when the engine is running, the timing belt will slip and I will have all sorts of trouble?


best regards

Ashley

[Quantum-man]

Surely if I loosen the 4 bolts holding the injection pump when the engine is running, the timing belt will slip and I will have all sorts of trouble?


best regards

Ashley

Not wanting to tread on H's toes here; but this is a simple one:

Loosening the bolts on the pump, effectively only rotates the pump relative to it's pulley and is not moving the pulley closer to the other pulleys. [It's actually an arc, but it's moving pretty well tangentially compared to the 'circle of the 3 pulleys so does not have the effect that you are rightly concerned about ]

In timing, the crucial element is to lock the cam in a fixed position with crank at TDC.

Then when belt is on, and then locks removed, the cam rotates in it's almost unique position, whilst the crank moves the pistons. Any [almost]other relative positions of pistons to cam, and at some point in rotation they will collide.

[82vdub]

Just thought of this now, but is the starting problem related to a glow plug issue, or an incorrectly timed injector pump?

[Ashley5031]

82vdub

This is not a glow plug problem...they are fine..The problem is that the engine is too hard to turn over. If the battery isn't completely fresh, I need to put a hand over the air intake to help the engine turn over.

[82vdub]

If you have to restrict the air flow to allow the engine to turn over faster, it sounds as though the IP is way too advanced. If it's injecting the fuel before the piston gets to TDC (or too soon), that combusts and pushes against what the starter is trying to do. I would do as suggested and set the static timing to crank TDC, IP locked with the locking pin, and the cam #1 valve lobes up and the cam locked. That's static engine timing and the engine should run in this position. Fine tuning the timing can be done by hand or with a dial gauge. As mentioned before, you've slipped the teeth on the timing belt, but where did you do the slipping? Maybe it's time to start over with the timing belt and static timing.

[Ashley5031]

I slipped one tooth on the crankshaft pulley, because it was just touching the valves and making a noise whn I rotated it by hand. So the timing notch on the pulley was just past its top posoition rotating clockwise.