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Engine Specific Info and Questions => IDI Engine => Topic started by: ghostrider2 on May 20, 2024, 01:02:06 am
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Hello everyone.
I've spent the last year swapping a 1.6TD JX into my 1981 VW Vanagon (replacing a broken 1.7KY NA Motor). I've swapped everything from a donor vehicle that I test drove shortly before removing the motor and transmission. In the process I replaced most the seals and sensors (aside from the head gasket and injector pump).
It's now finally in my bus, cranks and starts with the cold start pulled all the way out. When I give it gas or push the cold start back in it sputters and dies. Here's what I've checked so far:
- Set the belt timing to TDC
- Set the injection pump timing to 0.9
- Bled the injector lines
- Fed fuel directly into the injector from a clean container to bypass the filter and make sure it wasn't a filter problem
- Checked for power at the solenoid and glow plugs - yes
I have photos and video of the following but can't post them to the forum. I'll update the thread if I get permission.
- A photo of the injector pump timing set to 0.9.
- A video of the engine running and (you can't see it) but I push the cold start cable in and it stalls out. Please ignore the unfortunately timed air compressor turning on right at the end. You'll also hear my garage mate spraying the compressed air in the background (that's not my motor!) ;)
- a video of it running roughly and you can see the bypassed fuel system. Is it curious no fuel is coming out of the return line?
Only thing I can think of is to advance the pump timing but I don't really want to move it forward from the recommended settings until I've exhausted everything else. Thanks in advance for your help!
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I think your instincts are right.
The cold start lever is a great indicator of how well the timing is set.
I don't think .9 is the recommended setting.
At least around here it's closer to 1.
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I would like to see you bump that pump to 1.25 and see what it does. Is this an engine with a turbo? Those should have 155 bar injectors so you can overcome some of the extra pressure that comes with increasing the air into the cylinder. At the same time, you have increased the pressure and you need to inject the fuel earlier so it will take advantage of the increase and force that piston down sooner and you get the benefit of the extra power.
That is what I have going in the 1.6 diesel with a turbo on my PU and it seems to do better than if I run a standard 90 or an enhanced 1.05 mm timing.
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Thanks y'all. That's encouraging because adjusting pump timing is something I know how to do now! ;D
And, yes, it has a turbo. Just the standard VW version though. Nothing fancy.
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Here's the photos and videos as promised now:
Here is a photo of the injector pump timing set to 0.9:
https://share.icloud.com/photos/064BC4MzcBHpJ-pwJGzne6cqQ
Here's a video of the engine running and (you can't see it) but I push the cold start cable in and it stalls out. Please ignore the unfortunately timed air compressor turning on right at the end. You'll also hear my garage mate spraying the compressed air in the background (that's not my motor!) ;)
https://share.icloud.com/photos/03fCAdrAbU6B01hHT0huztHBQ
And here's a video of it running roughly and you can see the bypassed fuel system. Is it curious no fuel is coming out of the return line?
https://share.icloud.com/photos/0a9Tmg8i1T0ZJb6v9h6M-1vEw
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By all technical means you are timed at 89.8 mm. note the small dial and you have two more increments to go before you hit. 90 mm, I know it is tough to get it spot on but that is where you are at.
Since it is only at idle I would say no fuel return to the bucket is probably expected. Rev it up to 15 or 1800 and see what pumps through it.
Quite the clacker I say. Almost like it was over-timed. Oh wait, that is with the CS knob out, so that adds a few degrees advance to the system. Now how many MM is that? I don't remember. Dang.
Keep at it. and check that alternator support bracket for cracks, it looks wobbly to me, I wouldn't like to run it that way.
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There should be fuel returning even at idle.
There is a restrictor in the OUT bolt that can get clogged.
In fact the hole in that bolt is so small you might have a hard time finding it.
There is a screen inside the bolt that is supposed to keep that hole from plugging but it doesn't always work.
You should try backflushing it.
Or vacuum from the end of the bolt, or both.
I still think your problem is retarded timing but no flow from your pump will be your next problem once timing is right.
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there should always be fuel flowing through the return, the pump needs that flow to cool itself.
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Thanks for all the tips y’all. In the meantime I had a shorted aux water pump cause a few wires to burn and so I had to spend some time rewiring my harness.
But now that that’s done and a new pump is installed I advancing the timing to around 1.1mm and cleared the fuel lines of air. She starts and runs (I also ran a can of diesel purge through)! 🤩 The issue now seems to be that she’s only running on three cylinders (1, 2 & 3). 😣
Here is a video of the engine at idle and with a bit of gas. You can hear the angry tapping: https://share.icloud.com/photos/0cevD_-jF2FnmQGLgc_J9Y_QQ
Then here’s one of me checking the injectors and you can see there’s little reaction when I loosen injector number 4: https://share.icloud.com/photos/0ec8jX9MFZYJgiMPiahyXEBDg
Could the timing be advanced too far now? Anything else I should check before tearing apart the injector itself?
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Pull that #4 bad actor outta there and clean it up. I use a 10-power hand lens to look at the injector tips and sometimes I am amazed to see how much build-up is on them. They do clean up with solvent and a soft brass brush. It is burned on diesel, coke if you will, so it is not going to come off without some effort. If You have an ultrasonic cleaner they are the best tool to use for that job.
I don't but I do test them with a pop tester to get them back to proper BAR pressure.
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I don't know if you have access to an injector tester.
I've heard of folks taking the injection pump lines off,
putting them back on facing up with the injectors on and cranking it.
Sounds like it could be messy.
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Oh my goodness, That would have fuel spraying everywhere. But you could potentially contain each injector in a plastic see-through dish and MAYBE determine what kind of spray you have coming out of each one. I would just go get a cheap injector pump from Harbor Freight if I didn't already have one. It is always mounted on the bench just in case I have a strange noise under the hood. I can pull the injector and check it in less than five minutes.
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Yep, it is nice to have an injector tester nearby.
Then I reform the heat shields before reusing them.
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Alright. Thanks for the tips. Time to source an injector tester. No one thinks it’s still the timing?
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Timing should be OK where you have it ghostrider2.
Fatmobile, there are those on this forum that will shake their heads at that reforming habit of yours. But I am of like mind and manner. As long as you inspect them well for cracks in the center and replace them when they show up I can't see why reuse isn't a good thing.
I do have a set of 4 on hand at all times however should I need them.
I would hate to get stuck taking all of them off and having a mass failure event happen and need them to get back up and running.
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Because it's just one injector acting up, I don't think that could be caused by timing.
I'm not sure what the local bosch service center would charge just to test them.
Probably wouldn't be much.
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Following up here for future reading. Turns out the injector closest to the transmission was seized. I took the time to rebuild them all and was nervous to do the work but it turned out to be fairly easy and straightforward. Here’s a great video on the topic: https://youtu.be/EJa7l3ntWSo?si=HoIagN0LAViZNcwk
So it’s now running way better but still smoking a bit of white smoke at high RPMs and the oil pressure light is strangely on all the time even though my pressure gauge is showing at least 1bar at all times. Anyone had that issue before?
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Unfortunately I didn’t get to test them properly as the injector tester I ordered had imperial adapters 😒 I’m hoping the pressure is good with the rebuilt insides.
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Glad you got that part of the problem figured out.
Hagar had a way to make sure the injectors are somewhat matched.
When tightening the injectors back together, make note of when the spring starts to compress and when the injector stops turning.
If the degrees of turn are near the same, the spring pressure should be near the same along with breaking pressure.
I've never tested this method but it should get you close.
White smoke at high RPMs could be air in the fuel. At higher RPMs more fuel is being pulled from the tank
and that can create more of a vacuum at the front of the pump.
I have a dash-mounted vacuum gauge to tell how hard the pump is pulling.
It could also mean the timing isn't getting advanced enough at higher RPMs.
Internal pump pressure drives the timing advance piston.
There are a couple ways to make a tool that will display the internal pump pressure on a gauge,
by making a pedestal that screws into the top of the pump, that the OUT bolt screws into.
The gauge is attached to this pedestal.
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Ahh the mention of the man, Hagar. What a riot it was to read his stuff. And he was nearly a local to me. I never found the time to drive up the coast to meet him. My loss for sure.
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I think Hagar was also the one who first mentioned internal pump pressure and how to check it.
In a way.
He measured the pump output in liters and the pressure was relative to the amount of fuel that flowed from the pump at a given RPM.
he might even have hooked up a gauge too but my memory of where I first heard of it is vague.
Might have been something libby built.
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At the time I was reading Hagar on the forum of the time I took the liberty of capturing some of the fun facts that Hagar would throw out every now and then. I think I have them archived in a Word document on another long dead computer. But the hard drive is a solid state one and may yield the file if I would find the time to do so.
But, in my memory of the volume at RPM to get proper pressure I believe that Hagar would state that you should get 900 ml at 1000 RPM in one minute. If less then you were to tap down the regulator button at the front of the IP. By chance you were pumping more you were to remove the button, tap the regulator all the way out and reinstall it, tap it down some, and retest, tap, and test until you came to the magic numbers he prescribed.
I even tested his numbers by building a pressure gauge take-off as you state. Under the OUT bolt and I would tap and test by two lb increments and I think his 900 ml was spot on at 43 lbs. of internal pressure. More gets you advance sooner and less, which is what we generally see gets you later timing advance. That weak fuel as Hagar called it was the bane of the IP pressure and timing issues. No amount of dialing in the right mm of advance would cure thin fuel. He always added some sort of airline oil with no ash content I believe.
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Yep, that sounds about right.
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And I have people telling me I don't remember anything correctly anymore. HA Showed them.
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Amazing what we chose to remember, what we consider worth remembering.
And what we forget.
Many of my posts are for future me when I forget something.