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morymob
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Location: east-tn
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 Posted: Thu Dec 27, 2012 4:48 am Post subject: MOD the F.I. system? |
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| Has anyone studied the possibility, how hard, to adapt a jetta(?) ecu sys to get sequential fuel injection ?? Seems this would improve the mpg quite a bit or did i just have a bad dream?? I never leave mine alone, trying to make better etc. |
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AdrianC
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Joined: January 13, 2012
Posts: 526
Location: Wherever the road's gone
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| Posted: Thu Dec 27, 2012 5:10 am Post subject: Re: MOD the F.I. system? |
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| morymob wrote: |
| Has anyone studied the possibility, how hard, to adapt a jetta(?) ecu sys to get sequential fuel injection ?? Seems this would improve the mpg quite a bit or did i just have a bad dream?? I never leave mine alone, trying to make better etc. |
The mapping would be all wrong - you'd be better to put an aftermarket system in. Unless you're going to go direct injection (machining the heads, at the very least), there's no need for full sequential, since the valve timing is still going to govern when the fuel enters the chamber.
Megasquirt's the daddy of DIY aftermarket injection, and the cheapest.
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Adrian
Zookeeper of a miscellany of motoring silliness, from 0.75bhp to 9ft tall.
Living life on the road in an '88 2.1DJ Westfalia Club Joker Hightop.
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morymob
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Joined: November 09, 2007
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Location: east-tn
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| Posted: Thu Dec 27, 2012 5:30 am Post subject: |
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| U said mapping would be wrong, u mean the advance curve? I was thinking with the 1.9 dizzy as the mech advance could be modded also, and a 4 banger is a 4 banger as far as the ecu knows. Direct inj would be nice as u could jack the comp up and some good pwr but the pump for this would be really pricey plus all the other special parts that goes with it. |
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xoo00oox
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Joined: February 11, 2010
Posts: 2672
Location: East Nassau, NY
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| Posted: Thu Dec 27, 2012 5:34 am Post subject: |
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I had an 1835 bug engine that I was running with Jetta III obd1 fuel injection system. I combined the distributors to make one, used a coolant temp sensor reading off the oil, had the crank position sensor ring welded to the pulley, and made a bracket for the crank position sensor, I used the Jetta throttle body adapted to a FI bug manifold.
It ran very smooth and got 32mpg. |
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AdrianC
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Joined: January 13, 2012
Posts: 526
Location: Wherever the road's gone
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| Posted: Thu Dec 27, 2012 8:21 am Post subject: |
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| morymob wrote: |
| U said mapping would be wrong, u mean the advance curve? |
No, I meant mapping, since we were talking about injection, not ignition. At least, I thought we were...
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Adrian
Zookeeper of a miscellany of motoring silliness, from 0.75bhp to 9ft tall.
Living life on the road in an '88 2.1DJ Westfalia Club Joker Hightop.
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RGS Paul
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Joined: April 20, 2007
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| Posted: Thu Dec 27, 2012 10:12 am Post subject: |
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I've thought about this as well. I would like to see the ignition map for the Digifant II from the Jetta/Golf (anyone have the Bentely manual from one of these?). I wonder if it might work well on some of the hot-rodded WBX engines to give you better spark timing as well as allow you to rev a little higher. The fuel map should be taken care of by the Oxygen sensor so no problems there. It might also allow you to get rid of the idle stabilizer in the rear fender as that was incorporated into the FI brain of the Digifant II.
Paul
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D Clymer
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Joined: December 22, 2005
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Location: Issaquah, WA
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| Posted: Thu Dec 27, 2012 10:39 am Post subject: |
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| RGS Paul wrote: |
I've thought about this as well. I would like to see the ignition map for the Digifant II from the Jetta/Golf (anyone have the Bentely manual from one of these?). I wonder if it might work well on some of the hot-rodded WBX engines to give you better spark timing as well as allow you to rev a little higher. The fuel map should be taken care of by the Oxygen sensor so no problems there. It might also allow you to get rid of the idle stabilizer in the rear fender as that was incorporated into the FI brain of the Digifant II.
Paul |
Digifant II would work. It is a very similar system to the Digifant I system in the Vanagon. It does have a knock sensor ignition, though, so it would be trial and error to find a suitable place to mount the sensor on the WBX case. I'll be curious to see where GoWesty puts it on their upcoming EFI system retrofit.
That said, I don't think I would go to the trouble of going to Digifant II. I had a 1991 GTI 8V for seven years back in the early 1990s and that Digifant system felt exactly like it does in a Vanagon. It always started and was reliable, but it had poor initial throttle response and always felt laggy and like it wasn't running right. I found that poor grounds and vacuum leaks were the culprit most of the time, but I just never felt like it was a good system.
I do think retrofitting the Motronic 2.9 system from a Mk3 is an interesting idea. That system was a huge improvement over Digifant II. This system would require retrofitting the Mk3 throttle body and crank position sensor, though, so it would not be a simple retrofit.
I think if someone were to retrofit the EFI system from a VW inline engine to a WBX, they would find that it runs fine. The fuelingwould be close to optimal since it is airflow controlled. But the ignition advance is another story. That either would or wouldn't work well for the wbx, and since most of us can't change the coding in a factory ecu, Megasquirt is probably a better idea.
D |
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AdrianC
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| Posted: Thu Dec 27, 2012 11:57 am Post subject: |
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| RGS Paul wrote: |
| The fuel map should be taken care of by the Oxygen sensor so no problems there. |
I'm not sure that the theory holds - if it did, there'd be no point in ever mapping or re-mapping injection on anything with a lambda. Just fire up, drive, and let it sort itself out. Apart from the fuel going open-loop at full throttle and before the coolant's up to temperature, the usual narrow-band O2 sensors don't really operate very far outside stochiometry, and there's a fairly narrow range of adjustment available to the ECU.
I know that Megasquirt - and probably the other aftermarket ECUs - have software available that allow you to look at the results from a wide-band O2 and feed that back into fine-tuning the map. Even then, it's an iterative process.
| Quote: |
| It might also allow you to get rid of the idle stabilizer in the rear fender as that was incorporated into the FI brain of the Digifant II. |
Would that tie in to the existing idle control valve, or would it use a different valve?
One thing nobody's yet mentioned - for me, a big win on upgrading the injection would be to gain diagnostics - nice, simple, easy diagnostics. The Lucas injection on my old Saab 900T16 was great - total diagnostic kit was a wire with a switch, and a sheet of paper with fault codes. Plug in, flip switch, key, switch - count the flashing dash warning lights. Job jobbed. Saved me a lot of time and blood pressure when I had the coolant temp switch go south at certain parts of the temperature range, leaving me stranded in the middle lane of a busy motorway.
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Adrian
Zookeeper of a miscellany of motoring silliness, from 0.75bhp to 9ft tall.
Living life on the road in an '88 2.1DJ Westfalia Club Joker Hightop.
www.WhereverTheRoadGoes.com |
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bluebus86
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Joined: September 02, 2010
Posts: 11075
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| Posted: Thu Dec 27, 2012 12:06 pm Post subject: |
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| AdrianC wrote: |
| RGS Paul wrote: |
| The fuel map should be taken care of by the Oxygen sensor so no problems there. |
I'm not sure that the theory holds - if it did, there'd be no point in ever mapping or re-mapping injection on anything with a lambda. Just fire up, drive, and let it sort itself out. Apart from the fuel going open-loop at full throttle and before the coolant's up to temperature, the usual narrow-band O2 sensors don't really operate very far outside stochiometry, and there's a fairly narrow range of adjustment available to the ECU.
I know that Megasquirt - and probably the other aftermarket ECUs - have software available that allow you to look at the results from a wide-band O2 and feed that back into fine-tuning the map. Even then, it's an iterative process.
| Quote: |
| It might also allow you to get rid of the idle stabilizer in the rear fender as that was incorporated into the FI brain of the Digifant II. |
Would that tie in to the existing idle control valve, or would it use a different valve?
One thing nobody's yet mentioned - for me, a big win on upgrading the injection would be to gain diagnostics - nice, simple, easy diagnostics. The Lucas injection on my old Saab 900T16 was great - total diagnostic kit was a wire with a switch, and a sheet of paper with fault codes. Plug in, flip switch, key, switch - count the flashing dash warning lights. Job jobbed. Saved me a lot of time and blood pressure when I had the coolant temp switch go south at certain parts of the temperature range, leaving me stranded in the middle lane of a busy motorway. |
the vancafe diagnosis box is the thing to use with stock wasser boxers for checking out what is working or not in the van. You can rent one or buy (I bought) and it has saved countless hours of trouble shooting, plus i can watch the air fuel mix, engine temps etc... while I drive in real time, witht eh box mounted on my dash. no silly flashing lights to count. for diagnosis this is the way to go on a stock van.
One concern with modified FI is passing the strick nazi like smog inspection in california. any modifications are supposed to be inspected and approved, that can be a lengthy and involved process, and even if you do it right, years later smog tests can still be a hassel, lots of shops wont touch a modified car for smog testing, even if you have all the correct exemption papaerwork in hand. |
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AdrianC
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Joined: January 13, 2012
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Location: Wherever the road's gone
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| Posted: Thu Dec 27, 2012 12:25 pm Post subject: |
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| bluebus86 wrote: |
| AdrianC wrote: |
| One thing nobody's yet mentioned - for me, a big win on upgrading the injection would be to gain diagnostics - nice, simple, easy diagnostics. The Lucas injection on my old Saab 900T16 was great - total diagnostic kit was a wire with a switch, and a sheet of paper with fault codes. Plug in, flip switch, key, switch - count the flashing dash warning lights. Job jobbed. Saved me a lot of time and blood pressure when I had the coolant temp switch go south at certain parts of the temperature range, leaving me stranded in the middle lane of a busy motorway. |
the vancafe diagnosis box is the thing to use with stock wasser boxers for checking out what is working or not in the van. You can rent one or buy (I bought) and it has saved countless hours of trouble shooting, plus i can watch the air fuel mix, engine temps etc... while I drive in real time, witht eh box mounted on my dash. no silly flashing lights to count. for diagnosis this is the way to go on a stock van. |
That looks like a neat box of tricks. Except when it says "86-91", I'm guessing that means the Digijet injection? Our '88 2.1DJ is Digifant, so I guess no diagnostics this side of a multimeter... Pity.
| Quote: |
| One concern with modified FI is passing the strick nazi like smog inspection in california. any modifications are supposed to be inspected and approved, that can be a lengthy and involved process, and even if you do it right, years later smog tests can still be a hassel, lots of shops wont touch a modified car for smog testing, even if you have all the correct exemption papaerwork in hand. |
Over here, for vans of our age, it's just CO and unburnt HC that matter for the MOT.
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Adrian
Zookeeper of a miscellany of motoring silliness, from 0.75bhp to 9ft tall.
Living life on the road in an '88 2.1DJ Westfalia Club Joker Hightop.
www.WhereverTheRoadGoes.com |
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Ian
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Joined: August 28, 2002
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Location: 713
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| Posted: Thu Dec 27, 2012 1:14 pm Post subject: |
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| xoo00oox wrote: |
I had an 1835 bug engine that I was running with Jetta III obd1 fuel injection system. I combined the distributors to make one, used a coolant temp sensor reading off the oil, had the crank position sensor ring welded to the pulley, and made a bracket for the crank position sensor, I used the Jetta throttle body adapted to a FI bug manifold.
It ran very smooth and got 32mpg. |
Do you have any pics?? This sounds awesome!
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All your Buses are belong to us.
Love and good roads!
IN LOVING MEMORY OF ROB CRESS 1968-2012 |
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RGS Paul
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Posts: 663
Location: Los Alamos, NM
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| Posted: Thu Dec 27, 2012 2:40 pm Post subject: |
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| AdrianC wrote: |
| Quote: |
| It might also allow you to get rid of the idle stabilizer in the rear fender as that was incorporated into the FI brain of the Digifant II. |
Would that tie in to the existing idle control valve, or would it use a different valve?
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THey use the same valve so no problems there. I guess I am also assuming that the programed fuel maps are similar enough between the two that the limits of adjustment would allow for it to work. And I'd can the knock sensor since it really isn't needed on the WBX. If I ever have a van with an engine I don't love I might give it a go. Good excuse to rebuild it if it doesn't work. 
Paul
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morymob
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Location: east-tn
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| Posted: Thu Dec 27, 2012 3:00 pm Post subject: |
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| Maybe i wasn't very clear, i DO mean use the jetta or whichever sys used, to INCLUDE ecu from the same vehicle, not other brand accessories with wbx ecu as i know u currently can't reburn the ecu chips of the wbx. IAN, above seems close, this is what comes out of the woodwork when i get into my winter mode. Gonna pick up a jetta book this wk end and see how they do things. Back to our reguliar music.......... |
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AdrianC
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| Posted: Thu Dec 27, 2012 3:36 pm Post subject: |
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| RGS Paul wrote: |
| And I'd can the knock sensor since it really isn't needed on the WBX. |
Have to admit, I _really_ like the concept of a knock sensor - especially on an engine that's so far away and well aurally insulated that you won't hear any pinking. ESPECIALLY (DJ in mind here) on an engine that's so high compression that it's meant to be either run on higher octane than we easily get now, or have the timing knocked back to run on normal juice.
But, again, we're back from injection to ignition. Yes, of course, a half-decent modern setup will combine the two. With a lot more mapping.
I can't see the benefit of the Mk3 Golf setup - you've got the same work as an aftermarket ECU, retrofitting trigger wheels and changing other hardware. But you've got the same drawback as the current system, with difficulty remapping. Worst of both worlds.
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Adrian
Zookeeper of a miscellany of motoring silliness, from 0.75bhp to 9ft tall.
Living life on the road in an '88 2.1DJ Westfalia Club Joker Hightop.
www.WhereverTheRoadGoes.com |
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xoo00oox
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Joined: February 11, 2010
Posts: 2672
Location: East Nassau, NY
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| Posted: Fri Dec 28, 2012 5:58 am Post subject: |
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| Ian wrote: |
| xoo00oox wrote: |
I had an 1835 bug engine that I was running with Jetta III obd1 fuel injection system. I combined the distributors to make one, used a coolant temp sensor reading off the oil, had the crank position sensor ring welded to the pulley, and made a bracket for the crank position sensor, I used the Jetta throttle body adapted to a FI bug manifold.
It ran very smooth and got 32mpg. |
Do you have any pics?? This sounds awesome! |
I could not find any pictures of it in the bug, my house was broken into a few years back and 2 laptop computers were stolen amongst other things. There were many pictures and videos of it on one of them including a video of it running with the laptop hooked up to it using VAG-COM to scan it.
I dug up most of the parts used. The engine would always start up and idle in any temp and had a very smooth response. One thing I was just reminded of while looking throug the parts is I was actually using a generator, not an alternator with this set-up and the ECM was fine with that.
Shown here is the trigger wheel, this is normally inside the block on the MK3, I did modify it slightly on my lathe just to make it narrower. Also shown is the bracket for the crank position sensor, you can see where it would bolt to the fuel pump location on the case. The knock sensor was bolted to the this piece as well (the hole between the fuel pump stud holes)
Shown here is the modified distributor, on the MK3 it is used as a cam position sensor so the ECM knows which cyl is firing. There is only one trigger window and the mechanical advance from the bug has been removed. You can also see the knock sensor in this picture.
Shown here is the intake plenum, the bore has been opened up slightly to allow the MK3 throttle body to bolt on.
Shown here is the wire harness and voltage regulator and the coil.
Shown here is the idle stabilizer and injectors. The injectors were slightly modified to allow a hose to be clamped on them like the EFI bug engines were.
So why was it removed? The clutch arm went bad in the bug transmission so I had to take out the engine to fix it, I had been kicking around another idea in my head for a while and decided that was the time to put it work.
This was the result...
Vanagon WBX 1.9, Cabriolet radiator, MK4 coolant tank, Vanagon rear heater box under the rear seat opposite the battery, etc.
My friend wanted to buy the 1835 for his bug but he saw all the wires and got scared so I told him we could use another system with much less wiring. We used a Vanagon digijet to run the 1835, again very good results and it is still on it today.
Andrew- |
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Ian
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Joined: August 28, 2002
Posts: 4930
Location: 713
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| Posted: Fri Dec 28, 2012 8:25 am Post subject: |
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| xoo00oox wrote: |
| Ian wrote: |
| xoo00oox wrote: |
I had an 1835 bug engine that I was running with Jetta III obd1 fuel injection system. I combined the distributors to make one, used a coolant temp sensor reading off the oil, had the crank position sensor ring welded to the pulley, and made a bracket for the crank position sensor, I used the Jetta throttle body adapted to a FI bug manifold.
It ran very smooth and got 32mpg. |
Do you have any pics?? This sounds awesome! |
I could not find any pictures of it in the bug, my house was broken into a few years back and 2 laptop computers were stolen amongst other things. There were many pictures and videos of it on one of them including a video of it running with the laptop hooked up to it using VAG-COM to scan it.
I dug up most of the parts used. The engine would always start up and idle in any temp and had a very smooth response. One thing I was just reminded of while looking throug the parts is I was actually using a generator, not an alternator with this set-up and the ECM was fine with that.
Shown here is the trigger wheel, this is normally inside the block on the MK3, I did modify it slightly on my lathe just to make it narrower. Also shown is the bracket for the crank position sensor, you can see where it would bolt to the fuel pump location on the case. The knock sensor was bolted to the this piece as well (the hole between the fuel pump stud holes)
Shown here is the modified distributor, on the MK3 it is used as a cam position sensor so the ECM knows which cyl is firing. There is only one trigger window and the mechanical advance from the bug has been removed. You can also see the knock sensor in this picture.
Shown here is the intake plenum, the bore has been opened up slightly to allow the MK3 throttle body to bolt on.
Shown here is the wire harness and voltage regulator and the coil.
Shown here is the idle stabilizer and injectors. The injectors were slightly modified to allow a hose to be clamped on them like the EFI bug engines were.
So why was it removed? The clutch arm went bad in the bug transmission so I had to take out the engine to fix it, I had been kicking around another idea in my head for a while and decided that was the time to put it work.
This was the result...
Vanagon WBX 1.9, Cabriolet radiator, MK4 coolant tank, Vanagon rear heater box under the rear seat opposite the battery, etc.
My friend wanted to buy the 1835 for his bug but he saw all the wires and got scared so I told him we could use another system with much less wiring. We used a Vanagon digijet to run the 1835, again very good results and it is still on it today.
Andrew- |
Dude, you're a genius!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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All your Buses are belong to us.
Love and good roads!
IN LOVING MEMORY OF ROB CRESS 1968-2012 |
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xoo00oox
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Joined: February 11, 2010
Posts: 2672
Location: East Nassau, NY
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| Posted: Sat Dec 29, 2012 10:45 am Post subject: |
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Thanks Ian.
I think I could easily put this to use on a WBX engine. The harness, injectors, distributor, and crank position sensor bracket should all work with the WBX, I'd need to adapt the throttle position sensor or throttle body and attach the crank trigger wheel to the pulley, then adapt the MAF sensor to the intake and find a spot to put the intake temp sensor. The WBX fuel pressure regulator and oxygen sensor should be fine. Is this what you had in mind Morymob? |
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Vanagon Nut
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| Posted: Sat Dec 29, 2012 1:16 pm Post subject: |
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| D Clymer wrote: |
Digifant II would work. It is a very similar system to the Digifant I system in the Vanagon. It does have a knock sensor ignition, though, so it would be trial and error to find a suitable place to mount the sensor on the WBX case. I'll be curious to see where GoWesty puts it on their upcoming EFI system retrofit.
I do think retrofitting the Motronic 2.9 system from a Mk3 is an interesting idea. That system was a huge improvement over Digifant II. This system would require retrofitting the Mk3 throttle body and crank position sensor, though, so it would not be a simple retrofit.
I think if someone were to retrofit the EFI system from a VW inline engine to a WBX, they would find that it runs fine. The fuelingwould be close to optimal since it is airflow controlled. But the ignition advance is another story. That either would or wouldn't work well for the wbx, and since most of us can't change the coding in a factory ecu, Megasquirt is probably a better idea.
D |
Would the head seals on the WBX interfere too much with the transmission of any knocks? Like assuming the sensor was mounted on the block, would it pickup enough of any knocks?
I'm only a little familiar with Motronic 2.9 but had wondered about adapting it to the WBX (I mentioned this a while back)
The nice thing is that the TB is round as is the opening on the WBX intake. Seeing this in my my minds eye, it shouldn't be too hard to make an adaptor though maybe welding a 4 hole steel plate to the WBX hole would be best.
edit: .....
Of note, there are comments in the A3 Bentley regarding the early '93 OBD1 harness. In particular about wiring at/near the FI and hall IIRC. It's there in one of the first few diagrams.
edit: shoulda read this post to the bottom. I now see xoo00oox post of pics and stuff. Way to go man!
Neil.
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xoo00oox
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Joined: February 11, 2010
Posts: 2672
Location: East Nassau, NY
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| Posted: Sat Dec 29, 2012 3:12 pm Post subject: |
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| Vanagon Nut wrote: |
| D Clymer wrote: |
Digifant II would work. It is a very similar system to the Digifant I system in the Vanagon. It does have a knock sensor ignition, though, so it would be trial and error to find a suitable place to mount the sensor on the WBX case. I'll be curious to see where GoWesty puts it on their upcoming EFI system retrofit.
I do think retrofitting the Motronic 2.9 system from a Mk3 is an interesting idea. That system was a huge improvement over Digifant II. This system would require retrofitting the Mk3 throttle body and crank position sensor, though, so it would not be a simple retrofit.
I think if someone were to retrofit the EFI system from a VW inline engine to a WBX, they would find that it runs fine. The fuelingwould be close to optimal since it is airflow controlled. But the ignition advance is another story. That either would or wouldn't work well for the wbx, and since most of us can't change the coding in a factory ecu, Megasquirt is probably a better idea.
D |
Would the head seals on the WBX interfere too much with the transmission of any knocks? Like assuming the sensor was mounted on the block, would it pickup enough of any knocks?
I'm only a little familiar with Motronic 2.9 but had wondered about adapting it to the WBX (I mentioned this a while back)
The nice thing is that the TB is round as is the opening on the WBX intake. Seeing this in my my minds eye, it shouldn't be too hard to make an adaptor though maybe welding a 4 hole steel plate to the WBX hole would be best.
edit: .....
Of note, there are comments in the A3 Bentley regarding the early '93 OBD1 harness. In particular about wiring at/near the FI and hall IIRC. It's there in one of the first few diagrams.
edit: shoulda read this post to the bottom. I now see xoo00oox post of pics and stuff. Way to go man!
Neil. |
Thanks 'nut.
I'll second that comment by David, I don't think you'd have good luck with a MAP based engine management system. |
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D Clymer
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Joined: December 22, 2005
Posts: 2978
Location: Issaquah, WA
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| Posted: Sat Dec 29, 2012 5:39 pm Post subject: |
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| Vanagon Nut wrote: |
Would the head seals on the WBX interfere too much with the transmission of any knocks? Like assuming the sensor was mounted on the block, would it pickup enough of any knocks?
I'm only a little familiar with Motronic 2.9 but had wondered about adapting it to the WBX (I mentioned this a while back)
The nice thing is that the TB is round as is the opening on the WBX intake. Seeing this in my my minds eye, it shouldn't be too hard to make an adaptor though maybe welding a 4 hole steel plate to the WBX hole.
Neil. |
The
wet sleeve design of the WBX presents some interesting problems for knock sensor placement. The heads are mechanically coupled to the cylinders which are mechanically coupled to the case. So the knock sensor would be able to pick up detonation rumblings from either the head or the case at the cylinder base. You just can't mount it mid-cylinder like it is on a vw inline engine because that would be on the water jacket which is too remote from the combustion chamber due to the rubber top seal.
I have conceptualized adapting Motronic 2.9 to the WBX over the years and even salvaged the crank trigger wheel, throttle body, and some other sensors from a dead ABA someone gave to me. I always thought I would mount the ks at cylinder base level on the case. But when I studied the case more closely I found it wasn't thick enough there to drill and tap. I never revisited the idea.
I am intrigued (and impressed) to see that Andrew has successfully run a Type 1 engine with this system. It sounds like it worked out very well. It would be very interesting to see this system adapted to the WBX. My feeling is that the Digifant system is not worth working with. Megasquirt would be interesting, but it isn't as cheap as it first seems once you add everything up. The Mk3 Motronic parts are very plentiful in wrecking yards, and it was a really good and trouble free system on ABA cars.
Thanks, Andrew, for sharing the details of your Motronic retrofit. It's rekindled my interest again in pursuing such a development for the WBX. There's just never enough time to get to all these interesting projects...
D |
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