Gloyale Posted September 20, 2012 Share Posted September 20, 2012 (edited) I mean IACV, not TPS. Anyways, all the VW guys are saying that the obd2 subaru engines put out 5 pulses per revolution. I can build a converter or just tap off of my home brew GPS for the speed signal. nope It's 4 IDK......I am thinking you've got the wrong wire hooked up to the VSS signal. Where did you tap the VSS signal? And What color wire/which pin of the EJ harness did you hook to it? Edited September 20, 2012 by Gloyale Link to comment Share on other sites More sharing options...
kanurys Posted September 20, 2012 Author Share Posted September 20, 2012 I hooked the EJ Green/Red wire from the ECU to the Yellow/Red wire on the EA white gauge cluster plug. Is this right? I worked out a voltage divider circuit to make the 12v pulse into 5v at the ECU but still drive the Cruise Control. <Reed switch> | | |----------------<CC> | | <70ohm> | | |----------------<ECU VSS> | | <50ohm> | | | | <GND> The ecu might just think the signal is currently out of its voltage range (if its hooked up right). I can display the speed the ECU is reading vs. the EA speedometer in real time with my OBDII reader. This should be 1/4 the speed the gauge reads, according to Gloyale's post. Link to comment Share on other sites More sharing options...
Gloyale Posted September 21, 2012 Share Posted September 21, 2012 (edited) I hooked the EJ Green/Red wire from the ECU to the Yellow/Red wire on the EA white gauge cluster plug. Is this right? Any Chance you remember which white plug? Was it at pin 4 of the round one at the back of the dash? Or the 2 prong one that the dealer installed cruise control uses that's up above/behind fuse panel area? IDK if you have factory or dealer cruise. Probably dealer since the FSM for 87 only has a cruise schematic for Digi-dash, MPFI cars (GL-10's). I'm guessing that you need to tap the signal at the 2 prong connector up above the clutch pedal area/ behind fusebox. Find the dealer cruise wiring by starting at the brake switch, and follow the loom that is smaller, seperate, and wrapped in a slightly different tape. It will junction with the VSS signal wire. trace it from there up to the 2 prong connector and tap your EJ wire there. Edited September 21, 2012 by Gloyale Link to comment Share on other sites More sharing options...
kanurys Posted September 21, 2012 Author Share Posted September 21, 2012 Any Chance you remember which white plug? Was it at pin 4 of the round one at the back of the dash? Or the 2 prong one that the dealer installed cruise control uses that's up above/behind fuse panel area? IDK if you have factory or dealer cruise. Probably dealer since the FSM for 87 only has a cruise schematic for Digi-dash, MPFI cars (GL-10's). I'm guessing that you need to tap the signal at the 2 prong connector up above the clutch pedal area/ behind fusebox. Find the dealer cruise wiring by starting at the brake switch, and follow the loom that is smaller, seperate, and wrapped in a slightly different tape. It will junction with the VSS signal wire. trace it from there up to the 2 prong connector and tap your EJ wire there. Nice description. I'll try tapping in elsewhere as you suggest. Then I'll make sure i'm getting a signal from the cluster, then I'll wire in the voltage divider so the ECU gets a happy voltage. The white plug I'm talking about is the round one on the back of the cluster. I can't remember which wire I tapped into by count. Link to comment Share on other sites More sharing options...
kanurys Posted September 25, 2012 Author Share Posted September 25, 2012 (edited) Ok, scratch all the vss conversation from before. I had the ECU hooked up to the correct wire all along. Read on: Upon putting a meter on the reed switch signal at the cruise control computer connector (big one on the cuise box just above the hood latch lever) I found that it puts out 4.75v when closed and 0.3v when open (probably inductance). This should be within the acceptable range for the EJ ECU. I found that if the cruise computer was unplugged that I'd get a speed reading from the ECU. Plugged in, the ECU speed went to 0.0. This led me to believe that the cruise computer was somehow interfering with the more sensitive ECU, perhaps drawing current from it or visa-versa. Fist I tried a diode to try and eliminate current flow in one direction or the other. No luck. Then I tried a capacitor to isolate the ECU from the signal current but still letting it see the voltage changes. That was the ticket. It worked with both 100 micro-farad and 220 micro-farad capacitors. I just had these lying around, but probably any coupling cap will work. I soldered the 220 micro-farad in and shrink tubed it. My cruise control and EJ ECU now both get a speed signal and work great. Edited September 25, 2012 by kanurys Link to comment Share on other sites More sharing options...
Gloyale Posted September 25, 2012 Share Posted September 25, 2012 Then I tried a capacitor to isolate the ECU from the signal current but still letting it see the voltage changes. That is the ticket. It worked with both 100 micro-farad and 220 micro-farad capacitors. I just had these lying around, but probably any coupling cap will work. I soldered the 220 micro-farad in and shrink tubed it. My cruise control and EJ ECU now both get a speed signal and work great. Excellent finding. Glad you got it solved. Come to think of it, I've always adapted EJ cruise computers with my EJ swaps. I've never tried to interface EA cruise to an EJ computer. Props Link to comment Share on other sites More sharing options...
kanurys Posted September 25, 2012 Author Share Posted September 25, 2012 Thanks for your help. Link to comment Share on other sites More sharing options...
kanurys Posted September 25, 2012 Author Share Posted September 25, 2012 On the drive to work this morning the ECU was going haywire. Fans turning on individually, timing advance stuck at 45°, intermittent cut-outs, and died twice when coming to a stop, AND the ECU speed reading bounces all over from 0 to 200 mph... I think the ECU VSS pin might be floating when the signal goes low from the reed switch. A pull-down resistor between the cap and the ECU should do the trick. Then I have to put a smaller cap in there so it doesn't keep the signal high for too long. Strange how it worked great last night and totally nuts this morning. Link to comment Share on other sites More sharing options...
kanurys Posted September 26, 2012 Author Share Posted September 26, 2012 Upon a little more testing I found the following with cruise plugged in: With the cruise off the vss signal pulses between .3v and 3v. With cruise on the signal pulses between 3v and 6v. This is enough to satisfy the ECU and it works great. When the cruise is off the ECU sees a signal below trigger voltage and reads 0 mph, causing all sorts of problems, as stated earlier. Somehow the cruise is putting 3v dc on the vss wire. The plan: Try putting a diode between the vss and cruise allowing the signal to move only to the cruise computer from the reed switch. Then, if the vss wire voltage remains consistent no matter what the state of the cruise, I'll boost the signal with a little switching transistor to 5v. Now I just need a little time... Link to comment Share on other sites More sharing options...
kanurys Posted October 1, 2012 Author Share Posted October 1, 2012 (edited) I got the VSS working as well as the cruise, FINALLY. I ended up putting a 5v regulator and a transistor network together to use the reed switch to control pulses to the ecu and ccu completely separately and isolated so they don't talk to each other. It works like a dream and the car drives perfectly. It pretty much takes the one pulsed signal and gives me two outputs that tie to ground every time the reed switch is open (inverted signal). In the future, I will make a little micro controller which will convert the pulses to several so that I can match the ECU speed to the actual vehicle speed (tire size selector and pulse multiplier). A picaxe chip should be great for this since it's really easy code and completely reprogram-able. Edited October 1, 2012 by kanurys 1 Link to comment Share on other sites More sharing options...
subynut Posted October 2, 2012 Share Posted October 2, 2012 That is cool! Link to comment Share on other sites More sharing options...
kanurys Posted October 2, 2012 Author Share Posted October 2, 2012 The LED flashes every time the vss pulses. I think the pulse conversion will be important. Maybe I could sell a few of them? Link to comment Share on other sites More sharing options...
kanurys Posted March 24, 2013 Author Share Posted March 24, 2013 Well, the swap has been running great for about 6 months, now. It made it through the winter and a few -10°F nights. Below around 10°F it would be VERY hard to start and almost kill the battery if it did start. Crank for a few sec, wait, crank, wait, crank, etc.. each time it might fire once or twice and then not continue to run. Above 10°F it would take about 1 crank to start. The only codes are fuel vent solenoid (which doesn't exist), and fuel tank temp sensor (also doesn't exist). How the heck should I get rid of these? Weld a bung onto the tank for a sensor? Connect a vent solenoid? What have you guys done? I found that the engine is hard to start on cold starts if it reads a wrong temperature in the tank, though once started runs perfectly. This was tested with a variety of resistors to simulate the sensor. Link to comment Share on other sites More sharing options...
jaycanode Posted April 10, 2013 Share Posted April 10, 2013 I am working thru a transplant of a EJ25 into my 74 VW Bus. Concerning your fuel temp /pressure codes, there is a company called Small Car performance in Wasington that specialized in VW-Suby swaps. They make a board that will fool 7 sensors including the fuel sensors in the EJ engines. The board has adjustable outputs. The product is 65 bones, but it would probably only cure annoying codes and not your cold start issues. When cold, the temp sensor tells the computer to adjust fuel/air mixture for extreme cold. Fooling the ECU prob won't help this situation. An actual temp sensor would prob be best bet if that is even feasible. Link to comment Share on other sites More sharing options...
Steve W. Posted April 12, 2013 Share Posted April 12, 2013 Wow, your project is lookin' great. I'm almost there, the fresh engine (2.2t) is hangin' in the stand ready to go into my 88 GL10T. The next hurdle is the wiring, don't know whether to tackle it myself or buy one from someone else. Whata' ya think? Do you ever get down Santa Fe way?, I'd love to see your rig. Keep up the good work, Steve. Link to comment Share on other sites More sharing options...
kanurys Posted February 4, 2018 Author Share Posted February 4, 2018 It has been a long time since I got on here. I was having major issues with the car dying and could not figure it out. Today I pulled the HVAC airbox out and found the offender. One of the wires in the harness bundle going to the ECU had a nick in it from a sharp piece of metal under the dash. It would ground out in certain circumstances and kill the engine. These circumstances tended to be when driving up hill, on rough road in moderate to high ambient air temps. This wire was the Brown/White wire going to the Throttle Position Sensor. When it grounded out, it would not throw any codes. IT's FIXED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 1 Link to comment Share on other sites More sharing options...
kanurys Posted October 20, 2019 Author Share Posted October 20, 2019 (edited) Here we are, almost 2 years later. I've solved a few problems and am ready for another phase. Here's the solved list: 1. Nicked wire, as stated in last post 2. Mass Air Flow sensor went bad. A cheap new one fixed that. 3. Simple diodes (1n4007) with the annode facing the VSS reed switch in the cluster made the cruise control work and the 1999 ECU get the proper ground signal from the VSS. 4. Resistor network to fake Fuel temp, pressure and vent solenoid circuits. This results in NO check engine light (CEL) Moving forward I'd like to do the following: 1. Fabricate universal transmission mounts to get rid of bounce and play in the drive line 2. Struts and maybe swap original springs back in for softer ride - any recommendation on parts? 3. GPS/Nav/Diagnostics system - android tablet type to OBDII, speed readout 4. Cut, weld/box-in front strut top mount points for more camber adjustment I hope everyone is getting along well and life is treating you fairly. Keep on modding! Edited October 20, 2019 by kanurys Link to comment Share on other sites More sharing options...
FerGloyale Posted October 20, 2019 Share Posted October 20, 2019 On 10/2/2012 at 10:37 AM, kanurys said: The LED flashes every time the vss pulses. I think the pulse conversion will be important. Maybe I could sell a few of them? <<<<<"TaKe MuH mOnEy" meme here>>>>>> yes please I'll take 3. Link to comment Share on other sites More sharing options...
kanurys Posted October 21, 2019 Author Share Posted October 21, 2019 (edited) 16 hours ago, FerGloyale said: <<<<<"TaKe MuH mOnEy" meme here>>>>>> yes please I'll take 3. For now I'm just running a diode pointed toward the VSS reed switch. This seems to be working well. I don't really need the speed conversion to the ECU. I'm just curious, what advantage should having it sense the real speed be for you? From my testing, the computer just needs to know it's if the vehicle is moving or stopped to change rpm controlled by the computer. This supposedly reduces clutch wear when moving and drops the idle down to save gas when stopped. Edited October 21, 2019 by kanurys grammar Link to comment Share on other sites More sharing options...
kanurys Posted March 3, 2022 Author Share Posted March 3, 2022 Hello Everyone! I'm still here and still own my great Subaru. I've figured out a few electrical problem and have a good.... local car. It eats axles and I plan to go back to stock front springs from the Ford Tempo spring that are currently in there(I think I have a thread on the Ford springs on here). That should relive some of the axle angle strain and increase compliance. It will obviously decrease clearance, but it's how you drive it, right? My wife, dog and I were going to go on a hike in the mountains and the car kept dying when I stepped on the brake hard... She kindly pointed out that a few wires might be touching on the dummy conversion box I had dangling at her feet to, supposedly, make the car work better. Now she's the chief electrical diagnosis go to person (funny because I'm the electronics repair guy, professionally). "Why are those wires touching? Could that be it?" It's been running great ever since. I've recently acquired a 3d printer and am going to print something to hold a phone for a Torque Pro speedometer. There are a few tweaks that would make this rig more reliable and safe, like good alignment and better axle angles, etc... I'll probably make other threads for this, but I wanted to touch on this thread again for the fun of it. I hope everyone is still out there trying to keep these old rigs going! 1 Link to comment Share on other sites More sharing options...
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