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Engine only harness - VSS Simulator


frecobos
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Hi everyone,

I'm planning to use a EJ25 Engine on an Off Road car. For that, I need to get or to transform the current harness to an engine only harness.

 

The EJ25 engine is fuel injected and it uses an ECU which among other information it receives is the car speed from the VSS. In Off Road races, we don't use speedometers, So I need to find out how to satisfy the ECU need of knowing the vehicle speed.

 

So, far, I have found 3 options:

 

1) Use an std speed cable into my off road project and use RJES VSS (http://www.rjes.com/html/vss.html). The problem here is that if I later change the front suspension I would need another options for the vss.

2) Do something like using 4 magnets and a reed swith.

3) Use this speed sensor simulator: http://www.enginewiring.com/Products.html

 

However, the question for option 3 is:

How does the ECU uses the Speed info? I guess it has to adjust "something" depending on the speed the car running.

 

My concern with that device is that it could send a "Good looking" signal, not the right signal. And thus the ECU working with wrong information that could derive to an engine not performing as it could.

 

Any thoughts?

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When I put my EJ25 SOHC into my 88 RX I never hooked up the VSS and didn't have any problems. Some people have told me it could cause a performance issue, but the car ran a good 15 second quarter mile time at altitude so I doubt it really lacks any performance. I have an EZ30 in my 89 XT wired the same way with no VSS.... No problems there either.

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  • 2 weeks later...

On EA-82 VSS tells to ECU if you went more than 10 minutes at speed faster than 25 km/h then after swtching ign OFF it gives a 12V to air mass flow meter wire 0.5 seconds signal to clean-burn off dust from this meter wire. Without speed signal this cleening will be not. Ithink on EJ engines system is similar.

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:clap: Wow zilejanis. I think only few people knows this kind of details.

 

Of course I still need to verify if this is the case for my ECU. But if this is the case, then a simulator can work if it always tells the ECU that the car is running at more than 25 Km/h.

 

Interesting. I have read that some people that does not uses VSS on these ECUs, get their engines shut off at idle. Probably the ECU thinks that the engine has been running for a while without moving and shuts off the engine.

 

Well more things to investigate.

 

Regards,

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  • 4 weeks later...

you could use a speed sensor from a late model trans. it screws into the speedo cable hole. and is a two wire sensor.

 

if you want one to try out. let me know i have a few of them. from putting newer tranys into older cars. you just pull them out and screw the cable in the same hole...

 

i think tha makes since.

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  • 8 months later...
  • 4 months later...
  • 1 month later...

Does anybody know if the people from the VSS simulator at http://www.enginewiring.com are still in business?

Send them different e-mails and left an inquiry at their web-form.

 

Any info is appreciated, would like to have such a sensor in my EJ-XT project, now using the speed signal off the digidash, but that's not the correct voltage.

 

bram

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i bought a vss simulator from engine wiring.. im not 100% sure but i think it can and will mess with the ECU.. since its always pulsing, the ECU thinks the car is always driving.. weird idle, trouble codes that dont make any sence.. ive got a '82 brat with a EJ22turbo... the car runs and drives, but will go into limp mode.. ive heard of bad vss causing weird ECU codes..

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i bought a vss simulator from engine wiring.. im not 100% sure but i think it can and will mess with the ECU.. since its always pulsing, the ECU thinks the car is always driving.. weird idle, trouble codes that dont make any sence.. ive got a '82 brat with a EJ22turbo... the car runs and drives, but will go into limp mode.. ive heard of bad vss causing weird ECU codes..

 

hmm, weird. Shouldn't be happening I suppose.

 

My XT digidash is giving a 0-5V pulse, so that's perfect.

However, when plugging in the trip computer, it puts a 10V voltage on the wire, grounding it at the dash apparently and thus making it a 0-10V pulse. Yes indeed, sounds strange, wouldn't believe it, but verified on another XT, so I guess Subaru designed it that way.

 

The EJ20G ECU input has a range of 0-5V and only once while testing the set-up, I had an error code of 'input out of range'. Then never after again...even though I've been running the 0-10V pulse for quite a while now. Very strange.

 

Anyway, hopefully the guys from enginewiring.com will get back to me and maybe can also answer questions if the simulator can cause problems like you have/had.

Maybe some other experts can chime in why the ECU will have problems when having a constant speed pulse.

 

Bram

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i bought a vss simulator from engine wiring.. im not 100% sure but i think it can and will mess with the ECU.. since its always pulsing, the ECU thinks the car is always driving.. weird idle, trouble codes that dont make any sence.. ive got a '82 brat with a EJ22turbo... the car runs and drives, but will go into limp mode.. ive heard of bad vss causing weird ECU codes..

 

VSS should not cause limp mode on an OBD I engine. I would say disconnect that wire (for troubleshooting at least), and go from there.

 

 

 

I've worked with a bunch of buggy guys that have used the enginewiring.com simulator. always positive feedback.

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I've worked with a bunch of buggy guys that have used the enginewiring.com simulator. always positive feedback.

 

Good to hear this, I have good faith in their product. I also wouldn't know why the ECU would start to act funky when it get's a constant pulse on that wire.

From what I know, the ECU also doens't care if the pulses are speed related, only needs to know if the car drives/rolles or not. So this piece of electronics will I presume only give a constant pulse to the ECU, nothing more or less.

 

It's only strange they don't answer any of my e-mails or web-forms.

 

Bram

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