D-jet MegaSquirt&Spark system, Show Stock MSII system in D-jet box Options

[kertwerks]

Hello Group,
My name is Kurt and I love 914's and older 912's.
I have a product I've made for my girlfriends Volvo 1800 that might interest some of the members of your list.
I can offer a Megasquirt&spark engine management systems the modifies the D-jet distributor and replaces the FI timing cam and points with a magnetic trigger wheel and hall effect sensor. it dupicate the D-jet system to Show Stock Quality.
An O2 sensor bung in the exhaust and a vacuum line are the only thing to be added to your car.
I've set up an album on my fliker page here is a link:
http://www.flickr.com/photos/kertwerks/set...157627511841022 You can e0mail me of list @ kertwerks@mindspring.com
Kurt

[JamesM]

With a minor change to the MS injector circuit this can be done using the stock wiring harness and modifying nothing if you are going fuel only. Spark obviously requires dizzy modifications or a trigger wheel.

I have a board mocked up at the moment that integrates the injector circuit change and a couple other modification and solders directly to the stock d-jet ECU connector. Much easier then doing all the wiring to adapt to a stock MS system. Project has been on hold for a while now as life has been keeping me to busy but if you are intrested I can send you a PCB when i get a batch produced. would be nice to have some extra people testing it out.

Hello Group,
My name is Kurt and I love 914's and older 912's.
I have a product I've made for my girlfriends Volvo 1800 that might interest some of the members of your list.
I can offer a Megasquirt&spark engine management systems the modifies the D-jet distributor and replaces the FI timing cam and points with a magnetic trigger wheel and hall effect sensor. it dupicate the D-jet system to Show Stock Quality.
An O2 sensor bung in the exhaust and a vacuum line are the only thing to be added to your car.
I've set up an album on my fliker page here is a link:
http://www.flickr.com/photos/kertwerks/set...157627511841022 You can e0mail me of list @ kertwerks@mindspring.com
Kurt

[kertwerks]

[quote name='JamesM' date='Feb 5 2012, 11:42 AM' post='1618818']
With a minor change to the MS injector circuit this can be done using the stock wiring harness and modifying nothing if you are going fuel only. Spark obviously requires dizzy modifications or a trigger wheel.

James,
First, I'd be courious how you plan to use the stock TPS, I take stock TPS units and strip them to metal and have a Hundyi accent TPS assy presure bonded to the plate so it fits with the stock cover and plug. On the D-jet system the TPS acts simply as an accelerator pump to compensate until the MAP (hand grenade) vains catch up with the vacuum applied to it (note the car WILL run with the TPS unplugged).
Second, Are you reversing the fuel pump relay signal (the D-jet signal to the fuel pump is a negitive signal).

Also, when you start trying to work with the system as it is set up as D-jet wiring you'll learn all the little bitches trying to run the injectors as HiZ, Bosch added a resistor network to the heat sink of the ECU to make them appear that way to the ECU but the injectors are only 1.5-2.3 ohms and run much better at 70% in the PWM circuit in megasquirt programming.

DIY Autotune builds some PnP adapter units for some of the more comon applications but nthing they offered could be adapted to a system as archaic as D-jet.

I've converted 3 d-jet Volvo 1800's and 1 122 wagon that got a B-20 engine swap. The 122 is a daily driver and runs really well. All were done with the MS relay boards and external triggering rather then the new system that utiizes all the factory relays and sensors and really does look like a stock system with the exception of the O2 sensor on the exhaust that plugs into the side of the ECU case at the bottom of the heat sinc.


With regards to Bam's question about the Dizzy. What I do is take a D-jet dizzy and completly disassemble it. I remove the mechanical advance and mounting plate as well as the FI points from the FI points plate.
I mount a Hall Effect Sensor on the FI points plate and machine a 2" disc with 4, 3/16" magnets mounted in it and drilled to recieve the advance pins of the rotor shaft in the approiate position then press it onto the shaft, (the sensor and trigger wheel were the cause of most of the delays as transient noise in the dizzy was an issue that required a special order sensor because of case size needed to fit within the dizzy case and still be removable with FI points plate for service.
At this point you have a dizzy that is direct drive from the cam w/no advance. The spark signal normally sent from the points is an easy change over, simply unplug the trigger wire from the dizzy to the input at the tach. Plug in the spark trigger wire from the MS harness to the back of the tach in its place and, Bam mappable spark.

I'll keep the group informed on dyno results and progress.

Kurt

[JamesM]

This is more then a plan I have, I first put MS on a d-jet system back in 2005 and have been experimenting and tweaking things ever since. With my latest incarnation I was toying with the same idea as you of producing a totally stealth solution, one that would be plug and play to the point where you could just plug it in to an existing d-jet solution and go. I had a long thread going on it about 2 years ago, life has delayed things a bit though with a computer crash/data recovery, switching jobs and a new baby girl, been pretty busy.

there are some pics in that thread though if you want to take a look.
http://www.914world.com/bbs2/index.php?sho...05890&st=60
http://www.914world.com/bbs2/index.php?sho...5890&st=100

To answer your questions though... The stock d-jet TPS is unuseable with MS. One of my goals was to eliminate the need for all the d-jet pieces that are getting expensive and harder to come by, TPS, trigger points, MPS, cold start injector. Initally for the TPS I did the same as you and gutted a stock one and replaced the innards. I realized a few things with this method though. First from a production standpoint this would be a pain to do for every build. Second, while the TPS is nice to have with Megasquirt it is unneeded. You can jumper the TPS circuit in MS with a resistor and run without it. You will lose Flood Clear mode and TPS in your datalogs but you can still have accel enrichment by running MAP based and leave the stock sensor in place for looks.

As for the the Fuel pump circuit, the 914s fuel pump relay is activated by grounding the accoicated pin at the ECU. If you are not using the MS relay board then it is the same operation with MS, just plug the FP relay pin from the d-jet harness to the FP relay pin on the MS ECU and you are good to go. I would need to go find my notes on exactly which pins they are.

I dont trust PWM, seems most peoples failures with MS are related to it. I chose to go the same route as Bosch and run resistors in the circuit. I had initially used 10ohm 25W aluminum cased ones and in later builds switched to using the resistors in the injector circuit from the stock d-jet ECU as they were alreday mounted so nicely in the case. Think i will go back to the aluminum cased ones though as I have found there is a bit of variance in the stock resistors and i prefer consistancy.

What are you doing with the dizzy sounds like a lot of work for what is still just a 4 point pickup, I was hopeing you found a way to get something more like a toothed wheel in there. In my auto-X car I just locked the advance weights and plates and run a pertronx with a pullup resistor, fuel only builds i use a totally stock dizzy. Some people have said that running ignition with a 4 point pickup can cause unstable timming but i have yet to encounter a problem. Ideally though, next time the engine comes out I think i will switch over to a trigger wheel on the crank that one of the guys here produces.


[quote name='kertwerks' date='Feb 5 2012, 07:38 PM' post='1619134']
[quote name='JamesM' date='Feb 5 2012, 11:42 AM' post='1618818']
With a minor change to the MS injector circuit this can be done using the stock wiring harness and modifying nothing if you are going fuel only. Spark obviously requires dizzy modifications or a trigger wheel.

James,
First, I'd be courious how you plan to use the stock TPS, I take stock TPS units and strip them to metal and have a Hundyi accent TPS assy presure bonded to the plate so it fits with the stock cover and plug. On the D-jet system the TPS acts simply as an accelerator pump to compensate until the MAP (hand grenade) vains catch up with the vacuum applied to it (note the car WILL run with the TPS unplugged).
Second, Are you reversing the fuel pump relay signal (the D-jet signal to the fuel pump is a negitive signal).

Also, when you start trying to work with the system as it is set up as D-jet wiring you'll learn all the little bitches trying to run the injectors as HiZ, Bosch added a resistor network to the heat sink of the ECU to make them appear that way to the ECU but the injectors are only 1.5-2.3 ohms and run much better at 70% in the PWM circuit in megasquirt programming.

DIY Autotune builds some PnP adapter units for some of the more comon applications but nthing they offered could be adapted to a system as archaic as D-jet.

I've converted 3 d-jet Volvo 1800's and 1 122 wagon that got a B-20 engine swap. The 122 is a daily driver and runs really well. All were done with the MS relay boards and external triggering rather then the new system that utiizes all the factory relays and sensors and really does look like a stock system with the exception of the O2 sensor on the exhaust that plugs into the side of the ECU case at the bottom of the heat sinc.


With regards to Bam's question about the Dizzy. What I do is take a D-jet dizzy and completly disassemble it. I remove the mechanical advance and mounting plate as well as the FI points from the FI points plate.
I mount a Hall Effect Sensor on the FI points plate and machine a 2" disc with 4, 3/16" magnets mounted in it and drilled to recieve the advance pins of the rotor shaft in the approiate position then press it onto the shaft, (the sensor and trigger wheel were the cause of most of the delays as transient noise in the dizzy was an issue that required a special order sensor because of case size needed to fit within the dizzy case and still be removable with FI points plate for service.
At this point you have a dizzy that is direct drive from the cam w/no advance. The spark signal normally sent from the points is an easy change over, simply unplug the trigger wire from the dizzy to the input at the tach. Plug in the spark trigger wire from the MS harness to the back of the tach in its place and, Bam mappable spark.

I'll keep the group informed on dyno results and progress.

Kurt
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