Newly built 1.6TD. Fires and stops. Fires and stops. etc. w/ video

[TimpanogosSlim]

I'm sure a lot of you have seen my build thread in the IDI forum.

Long story short: bought worn out 1.6D, rebuilt with variety of parts into 1.6TD.

Having trouble getting it to start and run.

See video:

https://plus.google.com/+EricJorgensen/posts/do1UQ3W7KFC?pid=6075756900046484658&oid=115750060043260405034

So that's as far as i can get. There's no downpipe on the turbo, thus the smoke.

The starter is suspect. PO installed it when he was having trouble starting (low compression) and of course it didn't fix his problem. He's not sure if it was the right starter, isn't a diesel guy or a vw guy generally.

Edit: It appears, based on a sticker identifying it as part 17030, that this is the starter: http://www.oreillyauto.com/site/c/detail/ULT1/17030/01920.oap -- if you walk into an o'reilly auto parts store and ask for a starter for my '84 jetta diesel, this is the starter they give you. Also if you have a 12v VR6. So it should have enough oomph to turn over this engine, but maybe it's not as good as a starter from an automatic mk4 tdi.

The IP is suspect. It's the pump referenced in this thread: http://www.vwdiesel.net/forum/index.php/topic,32647.msg302111.html#msg302111

Car has an electric lift pump under the tank pushing enough pressure to hose down the whole engine by loosing the feed line from the inlet barb on the IP.

Injectors were rebuilt by an authorized Bosch service center with new Bosch nozzles of the ordinary 1.6 IDI variety, shimmed to the TD pressure (I forget the psi).

I'm not convinced that i am getting fuel into all four cylinders. If i crack the lines at the injectors, 1 and 4 squirt but 2 and 3 only seem to dribble. I don't have a helper here to watch stuff while i crank it.

I suppose it's possible that the timing is suspect as well. This is my first diesel. I used very good quality tools and set it to 1.00mm.

I am pretty sure that there has been just a couple gallons of diesel in the tank for the last year or so. But i do live in a desert. Fuel filter is new and seems to be fully primed (only fuel comes out if i open the bleeder screw on the top).

Any ideas?

[libbydiesel]

Without the electric pump on, which way does the fuel flow when cranking?

[TimpanogosSlim]

Without the electric pump on, which way does the fuel flow when cranking?

At present there is about a 3" air pocket in the return line. With the lift pump disabled (removed it's power source), when i crank the engine the pump does push the air pocket further toward the tank.

Occasionally, the lift pump alone has had enough pressure going to push air bubbles back down the hard line to the tank, dunno if it gets them all the way there or not.

Earlier today i had the injection lines completely off to check that they are not clogged with anything as they are old and rusty. I did that when i bought them too, and found no issues with them today (able to squirt brake kleen through each line).

Starting behavior is identical w/o the lift pump powered.

[libbydiesel]

Do you have an extra IN bolt?  If so, temporarily try replacing the OUT bolt with a second IN bolt. 

[TimpanogosSlim]

No, I don't. But it's funny that you suggested it.

This IP is pretty bizarre because it appears to have a zexel LDA lid from some mitsubishi diesel that was never sold in north america.

It has funky accelerator linkage and, as i received it, had a plug in the corner where the In banjo usually goes, and hovering about 1cm above that was a banjo with a hard line that ran behind the LDA and into the return banjo, which had a 2nd shutoff solenoid in it for some fool reason. Also, this is an M14 banjo. And it attaches to the side of the LDA instead of to a horizontal surface on the lid.

Initially i tracked down an M12 double banjo bolt for the inlet. After test mounting the pump i found that it was near impossible to rotate the pump toward the engine. I also decided that it was silliness.

So, i cut off the big weird dogleg and sealed off the superfluous 3rd port on the return banjo. I got a normal M12 banjo bolt for the inlet, and replaced the shutoff solenoid in the return with a normal M14 banjo bolt.

On the one hand, I did this without understanding what, if any logic the designer of the LDA and intake/return plumbing was applying. At the same time, they designed that for some other pump body.

It has occurred to me that there is an internal rib in the return banjo that the new banjo bolt wouldn't fit through until i applied some 400-grit sandpaper to take a few microns off the banjo bolt. And i don't know if the holes on the shaft of the banjo bolt are on the same side of the rib as the barbs are. I have access to a drill press so putting more holes in the banjo bolt is doable, but i don't see how it could flow worse than the shutoff solenoid.

So, there are plenty of reasons to suspect the IP.

I do still have my NA IP, and it is a recent rebuild and i have not messed with it except to steal some small parts for the cold start linkage, and i had the accelerator linkage off to test if it fits on the new pump (it does not) so the idle adjustment isn't going to be right.

I am considering going through the timing process again tomorrow, and considering installing the NA IP.

I have found someone local to me who has "about 10" VW 4 cylinder IDI injection pumps in various configurations and states of repair. So i could get a whole other TD pump and either swap on the VW-style LDA or use the whole other pump. But that's money i would rather not spend if i don't have to.

Here's the weird plumbing before i chopped it:




I really appreciate the help.

[libbydiesel]

Are you using the solenoid/OUT bolt that is shown?  Are you supplying it with 12v?

[TimpanogosSlim]

Nope. Replaced it with a perfectly normal m14 banjo bolt.

I can take pictures of the current configuration in the morning.

.:Sent by pneumatic tubes

[libbydiesel]

Did you replace it with a normal OUT bolt "or a perfectly normal m14 banjo bolt".

[TimpanogosSlim]

To be honest i don't know how in and out bolts vary. It's a generic banjo bolt. Hollow shank with a couple holes through near the head.

.:Sent by pneumatic tubes

[libbydiesel]

OUT bolts say OUT on the bolt head in big letters.  They also have a very tiny hole and a screen inside them.  Using a typical banjo bolt in the OUT position will disable your timing advance and make it run like crap above idle.  The good/bad news is that the banjo bolt is not your current issue. 

I would try cranking the max fuel screw in a couple turns.  Be ready to shut it down if it runs away.

[TimpanogosSlim]

that may be how a 2nd shutoff solenoid ended up in the out banjo.

I'll give it a try.

[TimpanogosSlim]

Irony: My bizarro pump not only still had the collar on the smoke screw, it appears to have been spot welded on - not just crimped.

I was able to peel off most of it but there are two rectangles that would need to be ground down and then chased with a threading die. Easier to replace the part.

Regardless, a couple turns is now the maximum excursion from the original set point, and this seems to be enough.

It did indeed start. And it did try to run away. Switching off the ignition stopped it in it's tracks. It was only running away for a fraction of a second.

What now? Dial it back in?

I should note that the spring return is not attached to the accelerator linkage at this time either. So the idle adjustment was likely all the way up as well.

I can put back in that stop solenoid on the return. will only take a minute to make a Y cable so that it is powered along with the stop solenoid on the pump body. I suppose in the future i might find an interesting use for switching it off. sounds like a bad idea though.

[libbydiesel]

All of the stock max fuel screws have the collar spot welded on.  The threads are M8x1.0 (fine thread). 

Make sure your accelerator lever return is working and that the lever is back to idle and try again.  It may just rev up to a couple thousand rpms.   

It sounds like a combination of max fuel and idle adjustment are causing your issue.  I would play with those two adjustments until you can get a decent idle.  If it runs away with the accelerator lever returned to idle then turn out the max fuel screw.  If it then will not stay running then turn the max fuel back in and back off the idle adjustment, etc...

[TimpanogosSlim]

huh, all the pages I've seen say the collar is crimped on.

Anyway. I was cleaning up the "out solenoid" when i noticed something that struck me as unusual.



The larger hole is open when the solenoid is not powered.

So this is not a normal stop solenoid, i presume?

some kind of advance mechanism perhaps.

[vanbcguy]

Bingo - two stage advance.  Probably flows through the small hole when not powered and the large hole when powered.  Most likely emissions related - advance produces NOx so it is not uncommon for auto makers to try and reduce it by disabling advance at certain times.  Some of the later AAZ pumps had a similar mechanism, though implemented differently than this.

You SHOULD be able to replace it with a normal OUT bolt (one that only has the small sized holes) and retain the normal advance function of your pump.  To be honest though I know how long you've been fighting with this pump - what, 3+ months now? I'd be looking for a normal VW pump top at the very least.