Author Topic: mTDI won't run, possibly flywheel issue? (Read 8749 times)

monkey magic · « **on:** December 21, 2008, 02:59:51 pm »

Ok, bear with me on this massive post :oops:

so I'm making slow progress with my mTDI syncro bus (read vanagon). After a day playing with timing, I have not got my engine to run, or even try to fire. It would have been some kind of miracle if it had run, given the circumstances (see below), but had to see if it would fire up 'as is'.

The engine:

Lowish milage AHU TDI, with Landrover 200 TDI mechanical pump. No obvious issues present (turns over, generates oil pressure). Oh, and its on a pallet, not in a van!

The symptons:

Fuel seems to be reaching the chambers, as it is blowing smoke out of the turbo, but does not want to even try and fire.

So, several possible issues:

1: I don't have the original gearbox, so have nothing to set the crank at TDC. My guesstimated TDC was from a piece of welding wire in No. 1 chamber, combined with looking at the 'starting edge' of the notch for the crank sensor. I'm happy I'm very near, but can't guarantee i'm not 1 notch out either way.

2: The starter im using is built for a 1.6 td engine (vanagon syncro box). I know this is a workable set up, but the starter is wrong AND old, could this be enough to stop it spining fast enough to fire up?

3: The pump, as I understand, should be set to 1.54 advance (as per 300TDI landy spec?..), I have it at around 1.4 - 1.5, but with no accurate TDC, this measurement isn't entirely accurate.

4: I don't have the glow plugs wired up. Read that the TDi's dont really need the glow heat in a UK type climate. Incidentally, I measured the resistance on them all, and they are each massively different, so may need replacing anyway.

5: The flywheel is machined down, to allow access to sump bolts when fitted (again, not original sump, but 1.6td sump). Also, at the moment there is no clutch bolted on either, so there is very little weight here. It has a LOT of meat machined off!

I think all of the above issues are not helping, to varying degrees, and know the first thing I should do is find an accurate TDC to work with.

But, I suspect that the main problem is the lack of momentum from the flywheel, which is a hell of a lot lighter than it should be.

I'm keen to hear what you guys think would be the main problem/problems, given the above list, particularly interested in what you think about the ultra light flywheel being the culprit.

(if you got this far, thanks for reading through all of the above :oops: )

lord_verminaard · « **Reply #1 on:** December 22, 2008, 07:12:40 am »

I think you have it covered pretty much- if it chugs with smoke but no fire, it is probably timing related. I would get that corrected right away. I think I read somewhere that the TDI requires at least 250 RPM's to start properly. (or maybe it's 450???) You could try hooking two batteries up to the starter momentarily to see if it will spin it over any faster. Although I would concentrate on timing first, as I have kick-started (push-started) a TDI before and it fired pretty quickly.

Good luck!

Brendan

monkey magic · « **Reply #2 on:** December 22, 2008, 11:11:45 am »

Cheers Brendan,

I'm going to test the glow plugs tomorrow, and if they work, I'll power them up and try to start it again.

Somebody is lending me an appropriate bellhousing so I can find TDC. Then at least I can time the pump up properly and see what happens.

vegged-out · « **Reply #3 on:** December 22, 2008, 12:41:43 pm »

I have a similar rig but with a bosch pump . I think your tdc methodology is pretty good but get a mark on the flywheel!
I am not familiar with the pump you have, and the sprocket, but is it possible the pump is 180 degrees off? on the bosch pump the lock pin hole on the sprocket is clear , and if the cam lock is in, the cam lobes on cyl. #1 are both up, and the ip is in time with the right cyl.
Michiel

monkey magic · « **Reply #4 on:** December 22, 2008, 01:24:12 pm »

Hi Michiel,

the pump I have is a bosch pump also, the pulley swapped straight over, and the pump itself bolted straight up (more or less).

I have the cam timed properly (No 1 is at TDC, both lobes pointing up), and the IP is timed up fairly well, ie pulley lock pin in place, and a quick fine tune with a Dial Test Indicator (only as accurate as my TDC, but should be good enough for the engine to at least try and fire)

It is possible that the pump is out of sync by 90/180/270 degrees, but I believe all these units are set up the same (injection pulse relative to the woodruff key/pulley position). Won't rule it out though. Just need to keep trying different things.

Am I underestimating the importance of the glow plugs perhaps? I always thought TDIs didn't need them as much as the IDI's.

jtanguay · « **Reply #5 on:** December 22, 2008, 03:22:14 pm »

Quote from: "monkey magic"

Hi Michiel,

the pump I have is a bosch pump also, the pulley swapped straight over, and the pump itself bolted straight up (more or less).

I have the cam timed properly (No 1 is at TDC, both lobes pointing up), and the IP is timed up fairly well, ie pulley lock pin in place, and a quick fine tune with a Dial Test Indicator (only as accurate as my TDC, but should be good enough for the engine to at least try and fire)

It is possible that the pump is out of sync by 90/180/270 degrees, but I believe all these units are set up the same (injection pulse relative to the woodruff key/pulley position). Won't rule it out though. Just need to keep trying different things.

Am I underestimating the importance of the glow plugs perhaps? I always thought TDIs didn't need them as much as the IDI's.

as long as you have good compression the TDI should start without GP's down to about 0C or maybe even lower? it'll just run a bit rough and maybe studder. maybe you should slowly increase timing until it runs.

jackbombay · « **Reply #6 on:** December 22, 2008, 06:22:27 pm »

Is it possible to put the pump locking pin in the pump sprocket in 2 locations? If so, you may have the pump timed 180* degrees out. Pretty easy to move it 180 degrees to check if you have one of the sprockets with 2 holes for the pump locking pin.

Greasecar · « **Reply #7 on:** December 22, 2008, 07:31:23 pm »

I am doing a similar swap with a LR 300 TDI pump on an ALH. I had to swap the pulley hub from a VW pump onto the LR pump and found that the relation of the woodruff slot in the pump output shaft to the TDC pin is 180 degrees off with the VW hub compared to the LR. I haven't finished building the engine so I haven't been able to determine whether it is a problem yet or not but I had planned on cutting a second lock pin slot before installing it just in case. It looked like the firing order of the delivery nozzles/engine cylinders differ between the two engines.

monkey magic · « **Reply #8 on:** December 23, 2008, 02:20:48 am »

Cheers people,

@Jtanguay, I suspected that was the case with the glow plugs, I was beginning to doubt this though. I'll wire them up anyway, it can only help.

@Jackbombay, it has only 1 locking pin hole, but:

@Greasecar, if Bosch put the woodruff key in a different position on the different pumps as you are suggesting, then this could be the problem.

How can I check which injector line is firing when? Will it be ovious if I loosen the injector line union and then turn the engine over by hand?

Hopefully the different firing order is actually the same, but just 180 degrees out of phase.

The IP pulley I have here in my hand has 44 teeth, so I can offset it in 90 degree intervals.

Think tonite I'll start by spinning the IP 180 degrees and adding glow plugs.

Mr Greasecar, how did you determine that the LR300 pump 180 degrees out? Did you set the 300tdi engine to TDC before/when you took the pump off, or are the timing pin holes at opposite sides relative to the woodruff key?

monkey magic · « **Reply #9 on:** December 23, 2008, 03:46:47 pm »

Think I've got to the bottom of this problem :oops:

I made an obvious mark on the crank pulley, and estimated the cranking speed.

I reckon its less than 100 rpm!! So once i've fitted a new starter, I'll report back with the findings!!

jackbombay · « **Reply #10 on:** December 23, 2008, 06:09:05 pm »

Ahh, weak starter.

Let us know how it turns out

snakemaster · « **Reply #11 on:** December 26, 2008, 12:24:51 pm »

what i do when i put a pump on a engine that has never been on before.
1 set to TDC fly wheel mark and i mark the crank pully to
2 have no 1 fuel pipe going to the injector slack
3 power to the stop solinoid on pump
4 turn injection pump and pump hand priming pump (priming pump inline from filter to injection pump)
5 and when i see diesel coming out of pipe at injector i no i am very close
then you can stick your dti gauge on to the pump and get it cock on
6 then put the timing belt on
7 then start your engine
8 if you wreck your engine dont come crying to me and i am not responsible for any thing that happens . good luck

a pick of the priming pump on a mk3 M-tdi golf

monkey magic · « **Reply #12 on:** December 26, 2008, 03:47:42 pm »

Like your method, I don't have a hand priming pump, I should probably get one.

I fitted the new starter today, it left me confused.

I reckon the original was cranking the engine at around 80rpm, the new one was an improvement, I estimated it to be spinning the crank now at 120rpm+. Still nowhere near the alleged required speed of over 250 rpm.

Bear in mind this is a 1.6jx starter, as it is a vanagon transaxle and the TDi starter wont fit. I know it is common practice to fit the 1.6 starter to a tdi when doing this conversion, so for the time being, I will assume that cranking speed isn't the main issue here.

I established the IP was rough timed correctly, ie it wasn't 180 degrees out, the right injector was firing at the right point. Next, I checked IP timing proper (DTI guage) with my more accurate TDC, and it is set to 1mm advance. It should be at 1.54mm. Would this alone be
enough to stop it firing? How close should a pump be before the engine will run?

I need to pull off the IP mount bracket to open the bolt holes up for more adjustment before i can get 1.54mm of advance, a job for the weekend...

blackdogvan · « **Reply #13 on:** December 26, 2008, 04:04:28 pm »

Hey MM, 1/2 way down the page are Karl's TDi starter adapters for either manual, slushbox & syncro vanagon transmissions.

edit** :oops: guess a link would have been helpful.
http://westyventures.com/parts.html

monkey magic · « **Reply #14 on:** December 26, 2008, 04:28:57 pm »

hey there,

i presume you mean the westy venture site?

Shame I never looked into that, I could make one of those adapters myself, I just heard "the TDi starters wont fit, just use the JX starter" and left it at that. Real shame because I just gave somebody a TDi starter for free

When I have a chance, I will upgrade to a TDi starter, (makes sense for a tdi engine) but for now I figure the starter shouldn't be an issue. Hope not, seeing as I just gave GSF 120 quid for one.