Forums
NautiqueParts.comNautiqueSkins.com - Correct Craft Upholstery and Part
  New Posts New Posts RSS Feed - Keeping your Protec EFI with a DUI system
  FAQ FAQ  Forum Search   Register Register  Login Login

Keeping your Protec EFI with a DUI system

 Post Reply Post Reply Page   12>
Author
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Topic: Keeping your Protec EFI with a DUI system
    Posted: January-30-2018 at 3:10pm
Disclaimer - I no longer have my 1994 Supra Comp with the Pro Boss 351 EFI. It has been replaced by a 1995 Supra Comp with the GT40. The 1994 was still running great, with the full Protec intact, when I sold it last year. And also, I know supposedly "EFI cant be kept without the ignition"

My brother and I took a Protec system and did some work identifying what is required from each module for the EFI to function. We hooked it up to an oscilloscope and determined the following.

Starting point was the thread on planet nautique containing this info
"7) The EFI module and the Pro-Tec module communicate with each other via the green/purple wire connected to terminal "C" of each module. No signal from the Pro-Tec module, then the injectors will NOT operate (check continuity of this wire). "

Both the ignition and the EFI module share the signal coming from the trigger connector terminal B. The shared wire is green/purple. This signal is a 4 volt (confirmed not 5 volt) signal that drops to near 0 each time a tooth on the trigger wheel goes past the hall effect sensor. From the oscilloscope we confirmed it's a 4 volt square wave. The trigger wheel has 8 teeth.

So, remove the ignition module and all the EFI module should be looking for is this 4 volt square wave.

The DUI distributor/coil puts out a 12 volt square wave from it's tachometer wire. This information was obtained from DUI. I don't know how this signal works as I don't have a DUI setup. Does it drop to 0 during each pulse and how many pulses per revolution?

I can't find the information but I recall reading somewhere that the EFI is looking for >300 rpm from the trigger to start firing the injectors.

It seems to my brother and I that a simple electronic device could be used to create a 4 volt square wave from the 12 volt square wave provided by the DUI. Feed this into the EFI module via terminal C and you should be able to have EFI without Protec ignition.

I'm the mechanical engineer and my brother is electrical, so I'll have to wait until my brother gets back to the USA to add what electronic device he had come up with. Just wanted to share what I've learned and get others thoughts.



Reference threads

- Protec conversion to DUI
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=34338&title=protec-ignition-swap

- Protec wiring diagram on first page
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=33526&PN=1&title=protec-ignition-replacement-question

- First thread I started on this topic
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=37481&title=pcm-protec-pro-boss-efi
Back to Top
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 3:12pm
I also created this thread because the previous owner of that 1994 Supra had done the Holley injector upgrade for ~$1000 so I was very interested in keeping EFI while I had the boat.
Back to Top
TRBenj View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: June-29-2005
Location: NWCT
Status: Offline
Points: 19650
Post Options Post Options   Thanks (0) Thanks(0)   Quote TRBenj Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 3:50pm
0v would be my expectation from the tach wire in a conventional distributor ignition. You’ll get 8 pulses per revolution of the rotor (4 per revolution of the engine since it’s a 4stroke v8).
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-05-2004
Location: United States
Status: Offline
Points: 3478
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 4:33pm
Originally posted by TRBenj TRBenj wrote:

0v would be my expectation from the tach wire in a conventional distributor ignition. You’ll get 8 pulses per revolution of the rotor (4 per revolution of the engine since it’s a 4stroke v8).


I read this and said to myself that I think you'll have a fluctuating voltage between 0 and 12 at the negative terminal of the coil with a conventional distributor. Since the tach wire hooks up there, it gets the same fluctuating voltage.

The boats are in hibernation but the plow truck was readily available for some experimenting and that's what I got was a 0 to 12 volt fluctuation. Checked it on my little distributor machine too.

Being homegrown and rather low tech, it doesn't have an oscilloscope so all I could do was watch voltage rise and fall on a digital voltmeter.

Like Tm said, a pulse for every firing of a plug.

I think your idea sounds good and is worth trying, but it sounds like you don't have a pro tec to try it on any more.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-05-2004
Location: United States
Status: Offline
Points: 3478
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 5:56pm
Originally posted by 2001Sunsport 2001Sunsport wrote:




I can't find the information but I recall reading somewhere that the EFI is looking for >300 ton from the trigger to start firing the injectors.









What does this mean? Or what's it supposed to say?
Back to Top
tryathlete View Drop Down
Platinum Member
Platinum Member
Avatar

Joined: April-19-2013
Location: Lake Villa, IL
Status: Offline
Points: 1235
Post Options Post Options   Thanks (0) Thanks(0)   Quote tryathlete Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 7:21pm
You won’t find this on PN
Back to Top
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 9:16pm
Sorry, was writing while on the plane, believe it autocorrected. It's supposed to be 300 rpm, I'll correct the other post.
Back to Top
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Posted: January-30-2018 at 9:20pm
Unfortunately I do not have the boat anymore so I can't test anything on an engine. When I get time I could try to set up some old protec parts on a bench again.

Originally posted by KENO KENO wrote:

Originally posted by TRBenj TRBenj wrote:

0v would be my expectation from the tach wire in a conventional distributor ignition. You’ll get 8 pulses per revolution of the rotor (4 per revolution of the engine since it’s a 4stroke v8).


I read this and said to myself that I think you'll have a fluctuating voltage between 0 and 12 at the negative terminal of the coil with a conventional distributor. Since the tach wire hooks up there, it gets the same fluctuating voltage.

The boats are in hibernation but the plow truck was readily available for some experimenting and that's what I got was a 0 to 12 volt fluctuation. Checked it on my little distributor machine too.

Being homegrown and rather low tech, it doesn't have an oscilloscope so all I could do was watch voltage rise and fall on a digital voltmeter.

Like Tm said, a pulse for every firing of a plug.

I think your idea sounds good and is worth trying, but it sounds like you don't have a pro tec to try it on any more.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-05-2004
Location: United States
Status: Offline
Points: 3478
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: February-01-2018 at 7:31pm
I think it's unwritten site rule #7 that says if you bring up something like this and get people interested, you have to do the testing you're talking about

So...........get that EE brother of yours involved and see if this will work even if it's only a bench test

How's the new old transplanted Borg Warner treating you?
Back to Top
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Posted: February-04-2018 at 1:40pm
Dang, gotta learn the rest of these rules    Once he recovers from jet lag and it gets out of the single digits in the garage we'll have to get it set back up.

I think we put 30 hours on the Borg so far. Runs great! I'll check shaft alignment again once she's in the water and should be good to go.
Back to Top
rosconole View Drop Down
Senior Member
Senior Member
Avatar

Joined: May-10-2008
Location: United States
Status: Offline
Points: 453
Post Options Post Options   Thanks (0) Thanks(0)   Quote rosconole Quote  Post ReplyReply Direct Link To This Post Posted: February-05-2018 at 7:14am
what kinda of holley injector upgrade was done for efi? is that a SEFI or Batch fire? Im guessing still speed density back then. I would have done FAST efi when I took my protech off but bridge I didn't want to jump off just yet and splice a bunch.
1989 ski nautique ,1991 barefoot nautique
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-10-2018 at 6:09am
Was hoping this thread would be updated with more results. I have a 94 SN with efi, that is currently experiencing protec ignition problems. I have ordered the Dui distributor and am going to at least try to keep the efi with the disturber. Based on the above info, I need to send it a 4v square wave signal. The Dui tach signal is 12v square wave and has 8 pulses per rotation. I plan to try a voltage divide circuit to get the signal down to 4v. It will be a few days before my Dui shows up. Worst case scenario, I do have a Holley 870cfm from my friends 68 Camaro. I really would prefer to keep the efi though. I’ll let you know how it goes. I’m open to any advice
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-05-2004
Location: United States
Status: Offline
Points: 3478
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: July-10-2018 at 7:42am
One bit of advice might be to do some reading on marine carburetors if you end up going with a carburetor

2001 Sunsport is around fairly often so maybe he'll see this and update it.

Otherwise I think it's worth a shot

And..............make sure you update with your results
Back to Top
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Posted: July-11-2018 at 1:26pm
Hey all, kind of forgot about this while working on my GT40 and skiing.

My brother's suggestion was to use a diode to drop the voltage and might need a resistor to sink a little power. PM me and I can get you in touch with him if you want to discuss in more detail. Electrical design is not my forte.

I'm pretty confident this project can work and you can keep your EFI. Might take a little tinkering.
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-11-2018 at 7:05pm
So today I installed the DUI. I then used a voltage diving circuit (2 resistors one through ground one through the 12v wire) going into the green purple wire going into the efi box. I tried starting it and was getting no spark. I assumed the problem was a lack of 10.5 v at the distributor. I charged up the battery and even ran a second battery with voltage just going to the 12v side of coil. Still no spark. Then I tried unplugging the tach wire from the distributor and the engine started and ran for a few seconds. It turns out the with the tach wire attached, I’m getting the fuel injectors firing, but no spark. When the tach wire is disconnected I get spark, but no fuel.

I’m assuming this is because the tach wire is essentially connected to ground with just a resistor between them as that’s how my voltage dividing circuit work. I am not an electrical guy, so I need to figure out if there’s such a thing as a 1 way valve for electrical current. If that’s the case or I figure out a different way to reduce the voltage, I might be in business.
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-11-2018 at 7:09pm
Originally posted by 2001Sunsport 2001Sunsport wrote:

Hey all, kind of forgot about this while working on my GT40 and skiing.

My brother's suggestion was to use a diode to drop the voltage and might need a resistor to sink a little power. PM me and I can get you in touch with him if you want to discuss in more detail. Electrical design is not my forte.

I'm pretty confident this project can work and you can keep your EFI. Might take a little tinkering.


I just did some googling, a diode is what I might need. I’ll have to wait until tomorrow to go to the electronic store to get one.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-05-2004
Location: United States
Status: Offline
Points: 3478
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: July-11-2018 at 7:42pm
Well Google didn't lie to ya".

That's the function of a diode.

There are a large number of different sizes so you should have some idea of the current going through the wire you're going to install it in when you go to get the diode.

If in doubt go big
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 11:17am
Diode didn’t help. At a bit of a standstill as I’m not sure what else to try. I tried a few sizes. I also tried a voltage regulator, but still no spark.
Back to Top
TRBenj View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: June-29-2005
Location: NWCT
Status: Offline
Points: 19650
Post Options Post Options   Thanks (0) Thanks(0)   Quote TRBenj Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 11:28am
The diode wasn’t backwards was it (obviously they are directional)?
Back to Top
desertskier View Drop Down
Gold Member
Gold Member
Avatar

Joined: December-19-2006
Location: Tucson, Az
Status: Offline
Points: 707
Post Options Post Options   Thanks (0) Thanks(0)   Quote desertskier Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 12:12pm
The white stripe on the diode should be closest to the module (away from the distributor).
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 1:05pm
The diode was the correct direction.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-05-2004
Location: United States
Status: Offline
Points: 3478
Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 1:13pm
How about a hand drawn diagram or a marked up original diagram of what you're doing complete with your voltage reduction circuit and diode shown?

Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 1:51pm
It runs! Without a diode and with just some different resistors. I have a hand drawn diagram, just need to figure out how to post pics
Back to Top
desertskier View Drop Down
Gold Member
Gold Member
Avatar

Joined: December-19-2006
Location: Tucson, Az
Status: Offline
Points: 707
Post Options Post Options   Thanks (0) Thanks(0)   Quote desertskier Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 1:54pm
What size resistors are you using.   Should be fairly large. 10k plus or you could be loading the tach signal down.
Back to Top
tryathlete View Drop Down
Platinum Member
Platinum Member
Avatar

Joined: April-19-2013
Location: Lake Villa, IL
Status: Offline
Points: 1235
Post Options Post Options   Thanks (0) Thanks(0)   Quote tryathlete Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 1:56pm
Originally posted by Mikewolf Mikewolf wrote:

It runs! Without a diode and with just some different resistors. I have a hand drawn diagram, just need to figure out how to post pics


CCF, making it possible to keep older boats running, one solution at a time!
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 2:17pm
I’m using a 680 ohm and a 330 ohm in a voltage dividing circuit. 680 between the tach and ecu and 330 between the ecu and ground.

Anyone know an easy way to post pics? Without photobucket, I don’t have a place to host them anymore.
Back to Top
2001Sunsport View Drop Down
Groupie
Groupie


Joined: October-07-2015
Location: MI
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote 2001Sunsport Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 2:21pm
Awesome!!! Glad we could prove PCM otherwise. They were the first ones to tell me this would be impossible.

Originally posted by Mikewolf Mikewolf wrote:

It runs! Without a diode and with just some different resistors. I have a hand drawn diagram, just need to figure out how to post pics
Back to Top
desertskier View Drop Down
Gold Member
Gold Member
Avatar

Joined: December-19-2006
Location: Tucson, Az
Status: Offline
Points: 707
Post Options Post Options   Thanks (0) Thanks(0)   Quote desertskier Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 2:29pm
What resistors were you using when it didn't run?
Back to Top
Mikewolf View Drop Down
Newbie
Newbie


Joined: July-09-2018
Location: Ontario Canada
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikewolf Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 2:36pm
I tried 10k and 5k and also 8.2 and 4.7 ohm

With the 10k and 5k, there was no signal getting to the ecu. With the 8.2 and 4.7 ohm, the ecu was getting signal, but the distributor was being grounded out.
Back to Top
Gary S View Drop Down
Grand Poobah
Grand Poobah
Avatar

Joined: November-30-2006
Location: Illinois
Status: Offline
Points: 11815
Post Options Post Options   Thanks (0) Thanks(0)   Quote Gary S Quote  Post ReplyReply Direct Link To This Post Posted: July-12-2018 at 2:44pm
Originally posted by 2001Sunsport 2001Sunsport wrote:

Glad we could prove PCM otherwise. They were the first ones to tell me this would be impossible.   


My experience too, but in their defense we are talking about long out of production engines. Would be nice if they and their parent company could help a little........
69 Mustang HM SS
95 Nautique Super Sport
Back to Top
 Post Reply Post Reply Page   12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Copyright 2018 | Bagley Productions, LLC