VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: libbydiesel on April 17, 2015, 11:04:16 am
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I've done a little thinking on what would be required to retrofit the complete AHU or ALH electronic engine management onto a 1.6TD. It woudl be fairly easy for me to create a 1.6 electronic VE injection pump. The necessary components would be an AHU base pump fitted with the 1.6 camplate, advance piston/spring and 9mm plunger/head assembly. I believe that the crank position sensor could use a custom bracket and read off the crank pulley mounting bolts. One of the bolts is offset, though, which might screw it up. An alternative would be to use a steel crank pulley and drill 4 holes evenly spaced for the position sensor to read. I believe that the #3 injector pintle lift sensor could be replaced by a tiny-tach piezo transducer on the #3 line. Some signal conditioning might be required. I believe that all of the other AHU or ALH electronic engine management components would swap over.
I am interested in hearing what the perceived benefits and downsides would be to installing such a system.
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i don't think there is much benefit, it'd be interesting to see though and a fun project. i believe bmw made an idi injector with a lift sensor in it that is compatible with vw's. this has actually been discussed before. it'd be really easy with a aaz internals in a tdi block as that covers your crank sensor. i don't really see a huge benefit though since the computer only controls the fuel quantity as i understand the timing curve is still mechanical
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Interesting info on the pintle lift equipped IDI injector.
The e-pumps have an added solenoid at the bottom of the injection pump that opens/closes a channel between the case pressure side of the advance piston and the pump inlet pre-vane pump. That solenoid is controlled by the ECU and can regulate (by retarding) timing on-the-fly by decreasing advance piston pressure. The 1.6 e-pump could be set with less advance spring pre-tension so that the timing advance without 'electronic interference' was always overly advanced. At that point the electronic management would be able to retard the timing to the desired setting on the fly. A custom ECU 'tune' would be required.
Any opinions on what the real-world difference in performance or fuel economy could be vs. a well-tuned fresh all-mechanical pump?
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in that case you could really tune it in but im sure you know that, the only way i could think to compare would be a e-tdi vs a m-tdi and how do they compare.
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Benefits... probably smoother running at lower RPMs due to being able to retard the timing significantly when the advance isn't needed... If you continue to use a MAF you'd be able to limit smoke quite a bit as you'd actually know when the turbo spools... And of course being able to run a VNT properly. Virtually everything the VE computer does that's different from a mechanical pump is to reduce noise and smoke.
Whether that's worth doing or not... well... what's a used AHU worth? By the time you've got everything sorted wouldn't it be cheaper to use an AHU instead?
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It's a hypothetical discussion. I don't plan on doing it myself. ;) I have my own staunchly set opinions on the matter but I know what those are. I'm looking for other folks' opinions on it. :)
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I'll bite (first cut)...
"e-1.6TD" benefits/advantages: reduces smoke & timing issues,
crank sensor can be used for tach input similar to gassers?,
better idle stability,
easier VNT turbo control,
can take advantage of cheaper IDI engine hard parts vs. TDI hard parts for swaps
"e-1.6TD" disadvantages: wiring complexity issues (incl. ECU, immobilizer, cluster?)
requirement for drive-by-wire throttle swap or?,
increased costs-need for additional TDI pump & wiring parts,
less applicable to Mk1, MK2 cars (where most of the IDI's are...),
I'd rather have a m-TDI than either a e-1.6TD or regular 1.6TD for almost any application.
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Anyone have any opinions on reliability?
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If built with all factory parts it should be as reliable as an AHU. Meaning you'll be mostly fine till things get old, then limp mode becomes a distinct possibility.
The e-TDIs do seem to have a lot more injection pump issues from what I've seen on TDIclub. You rarely see anyone over here with a legitimacy broken IP that hasn't been messed with or sitting for a long time. Lots of posts with people needing new pumps over there.
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The Citroen xantia 1.9td uses an injector with an electrical connection[ number2 from the belt end] and a computer but has a injection pump similar to the jx pump.