And yet another Toyota swap, but M-Tdi.

JaysinSpaceman

Veteran Member
Joined
Aug 5, 2008
Location
Skull County, Ca
TDI
Golf
First a big thanx to kajikidu for giving me a good deal on a Diesel pulse timing light adapter for my m-TDi conversion. It works great so far.

Now some info on the dynamic timing advance for those that go the m-TDi route. When I built my pump I went with the current info that I could find (at the time) and used the e-TDi timing spring. I have fought with one of two conditions when I changed the static pump timing. Either the engine started well with little glow plug and sounded rattly at higher speeds and loads (when I would advance the timing) or I had to use the glow plugs even when the engine was warm if it sat for more then a half hour but it revved smooth and didn't sound rattly at higher RPM and load.

Now that I have a timing light adapter I did a few tests. From info I have found on timing with a light, 12 degrees BTDC at idle seems to be the best setting for most everyone. So I set the timing to that with the E-TDi spring and the truck was very hard to start but revved nice and smooth. The I swapped the timing spring for the original stiffer Cummins 4BT spring I had and rechecked the timing (note: I did not move static timing at all) and it was now idling at 4.5-5 degrees BTDC. So I reset static timing to 12 degrees BTDC at idle with the new spring and now the engine starts great and it revs smoothly with lower EGTs and much less rattle.

Moral of this story is that the stock E-TDi timing advance spring is FAR to soft and advances far too soon/too low RPM in a M-TDi pump without the E-TDi's ability to lessen timing with the computer. The Cummins may not be ideal but it is much better then the E-TDi spring. I will be doing more testing at various RPM for more data so I can figure out the advance curve of the Cummins spring, and I will also test a E-TDi with my light and see how the two advance curves compare. I should then be able to compare the physical spring rates between the two sparings and find a suitable spring rate to get close to the stock E-TDi curve.

Anyway, I thought people should know what I have found. I will continue to add more M-TDi tuning info as I go. And unlike those that are trying to make a living with the hows and whys that go into M-TDi pumps and tuning I am happy to give you what I find as it is all just a means to an end to get my truck to run well get good MPG and pull like a freight train.

That's it for the Spaceman Radio Hour. Thanx for tuning in.
Jaysin
 

vanbcguy

Veteran Member
Joined
Feb 22, 2013
Location
Vancouver, BC
TDI
'93 Passat - AHU mTDI with GTB1756VK
Super useful information! I have a pulse adapter myself. I'm using the stock Rover spring, if you want me to try and get a couple comparison data points I could see what I can do - it's a bit tricky to hold lower RPMs on my setup though with the engine in neutral (once the turbo spools it wants to GO)
 

JaysinSpaceman

Veteran Member
Joined
Aug 5, 2008
Location
Skull County, Ca
TDI
Golf
Yeah more data won't hurt that's for sure. The catch to that is we will really need the spring rate of that spring to make a good comparison. If you or anyone else has any extra timing advance springs they're willing to donate to the cause I have access to a spring scale so I can measure their rates. Then I could install them in my pump to get an advance curve. I could then send them back to you.

Jaysin
 

vanbcguy

Veteran Member
Joined
Feb 22, 2013
Location
Vancouver, BC
TDI
'93 Passat - AHU mTDI with GTB1756VK
The only spares I have are for IDI pumps, probably not what you want.

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JaysinSpaceman

Veteran Member
Joined
Aug 5, 2008
Location
Skull County, Ca
TDI
Golf
The only spares I have are for IDI pumps, probably not what you want.

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Actually they should be checked out for spring rates too. While a different style of injection they are VW spec. And do not use any outside timing like the e-TDi does. If you want I would be happy to test them just make sure that they have the pump number with them so other people could order the spring (ordered by pump PN) and so we can keep them organized.

Thanx,
Jaysin
 

vanbcguy

Veteran Member
Joined
Feb 22, 2013
Location
Vancouver, BC
TDI
'93 Passat - AHU mTDI with GTB1756VK
Sure. I know from my IDI days that the IDI pumps do not provide anywhere near as much advance as the DI pumps - the cap is about half the length of a DI one meaning the timing piston cannot move as far. The spring itself is shorter too.

That said I have a scrap 1.6TD pump that I'm more than happy to send the advance spring / shim / timing cap from if you want to take measurements.

Another avenue would be to message Goran (Dieselmekken) - he is pretty good about sharing information.

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JaysinSpaceman

Veteran Member
Joined
Aug 5, 2008
Location
Skull County, Ca
TDI
Golf
Sure. I know from my IDI days that the IDI pumps do not provide anywhere near as much advance as the DI pumps - the cap is about half the length of a DI one meaning the timing piston cannot move as far. The spring itself is shorter too.

That said I have a scrap 1.6TD pump that I'm more than happy to send the advance spring / shim / timing cap from if you want to take measurements.

Another avenue would be to message Goran (Dieselmekken) - he is pretty good about sharing information.

Sent from my XT1097 using Tapatalk
So I wanted to talk about this but had no time this morning. I have tested coil bind height on the two springs I have and they bind at the same height even though the e-TDi spring is much taller when unloaded. And as far as I can tell the spring seat depth is very close to the same in both the TDi cover and the Cummins cover the only difference is that the TDi cover is recessed so that the timing piston can move farther toward advance. The difference in length between the long TDi spring and the Cummins is that the TDi spring has much more preload (like 3/8"+ preload vs 1/16" for the Cummins). The stiff Cummins spring will allow the timing piston to move just as far as the soft e-TDi spring just at a higher fuel pump internal pressure.

I would definitely like to get some more specs for other springs.

Thanx,
Jaysin
 

JaysinSpaceman

Veteran Member
Joined
Aug 5, 2008
Location
Skull County, Ca
TDI
Golf
Chkn,

Sorry for the lack of updates, just too busy.

No timing spring updates as I haven't found a good source for them. If anyone has some that they'd be willing to part with shoot me a PM. I'd like to test a few of the IDI pump timing springs, from research it seems that there are at least 2 or 3 different IDI springs. I could use a slightly softer one then the current Cummins 4BT spring for a bit more advance at higher RPM.

As for the swap itself. Things have been great for the most part. I had a valve cover leak but it's fixed now. I blew a boost hose off once. Other then those things it has been an uneventful 6000+miles on the new motor. So far with the new VNT controller I made and the motor breaking in as I put more miles on it the MPG keeps increasing with every tank, it's getting 31.6 MPG (it started at about 28.5 MPG just after it was rebuilt). I don't spend much time on freeways, mostly country highways and roads, but I would bet I could hit 33-34 MPG maybe even 35 if I drove on freeways more. The power is great but I haven't had time to get the truck on a dyno yet, when I do I will be sure to post up numbers. Over all this is about the perfect small truck engine, too bad we here in the US don't get ANY of the good trucks the sell to the rest of the world.

Thanx,
Jaysin
 
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cumminsfromthecold

Veteran Member
Joined
Oct 27, 2006
Location
HumCo
TDI
'84 Toyota 1Z 4WD x-cab
Jaysin,
I can't believe you checked out so soon and so fast. Holy s$#!. You lucky guy. While snowboarding! Sure wish I would've visited. I'd been thinking about it lately, too. Dam^, it was good meeting you online, meeting and hanging out in San Pablo around your new, factory-looking '81 Toyota TDI. I'd never really seen anything like it. I remember well our meeting up for the adapter plate you made me in Rocklin in September (for which I am forever grateful), and watching you build and rebuild that Toyota. I couldn't believe you loaned me your precision-made tools for the 1Z intermediate bearing replacement. For free. Like I said when we met, you're a rare picture of craftsmanship. As one mutual friend of ours observed, 'everything that guy touches turns to gold.' You made it look easy, too. From our conversations both virtual and in person, you've done some pretty cool stuff and in a way that esteems doing the best job you can. Quality. The praxis involved in valuing that virtue seems largely lost these days. I find it most respectable and an attribute that all teachers should have – it moves students effectively, and so you must've been a fine teacher. How shocked your students must be! And Sara, who I've not met. Philosophy I find a fine comfort, and I hope she does, too.



Who will replace you? Impossible.



What do you think did it to you? The smokes? The welding fumes? Genetics? I wonder what will get me and why. It doesn't keep me up at night, I just sometimes wonder. That you escaped cancer, Fukushima's winds and waves, a Trump or another Clinton presidency, and a host of other possible prolonged miseries makes you even luckier. But there are those you'll miss and who will sorely, dearly miss you, and, stunned, I can only say I'm really sad that I won't be seeing you again. I am shocked and saddened. Happy travels, Jaysinspaceman. Elvis loves you. Thanks for showing us not just how it's done, but how to do it right.
 

deejaaa

Veteran Member
Joined
Apr 15, 2007
Location
Baytown, Texas
TDI
FOR SALE, 2002 Jetta GLS, 5 speed
Jaysin,
I can't believe you checked out so soon and so fast. Holy s$#!. You lucky guy. While snowboarding! Sure wish I would've visited. I'd been thinking about it lately, too. Dam^, it was good meeting you online, meeting and hanging out in San Pablo around your new, factory-looking '81 Toyota TDI. I'd never really seen anything like it. I remember well our meeting up for the adapter plate you made me in Rocklin in September (for which I am forever grateful), and watching you build and rebuild that Toyota. I couldn't believe you loaned me your precision-made tools for the 1Z intermediate bearing replacement. For free. Like I said when we met, you're a rare picture of craftsmanship. As one mutual friend of ours observed, 'everything that guy touches turns to gold.' You made it look easy, too. From our conversations both virtual and in person, you've done some pretty cool stuff and in a way that esteems doing the best job you can. Quality. The praxis involved in valuing that virtue seems largely lost these days. I find it most respectable and an attribute that all teachers should have – it moves students effectively, and so you must've been a fine teacher. How shocked your students must be! And Sara, who I've not met. Philosophy I find a fine comfort, and I hope she does, too.



Who will replace you? Impossible.




What do you think did it to you? The smokes? The welding fumes? Genetics? I wonder what will get me and why. It doesn't keep me up at night, I just sometimes wonder. That you escaped cancer, Fukushima's winds and waves, a Trump or another Clinton presidency, and a host of other possible prolonged miseries makes you even luckier. But there are those you'll miss and who will sorely, dearly miss you, and, stunned, I can only say I'm really sad that I won't be seeing you again. I am shocked and saddened. Happy travels, Jaysinspaceman. Elvis loves you. Thanks for showing us not just how it's done, but how to do it right.
did i miss something?
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
Sad, sorry for his family's loss.
 
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