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Jumping voltage
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toytech01 Offline
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Post: #1
Jumping voltage
OK, I found the signal wire and got everything hooked up. The voltage jumps between 150's and 190's. I turned the set screw one time to the right and waited and did not see any real change (volts jump around too much to really tell) I went the other way one full turn past were it started and still no noticible change. Should it be this irratic? How far should you turn the set screw to see a difference?
Thanks
06-11-2008 02:59 PM
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toytech01 Offline
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Post: #2
RE: Jumping voltage
Mike? Anyone? The voltage seems the same as when I just probed the O2 sensor wire.
06-12-2008 05:41 AM
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mike Offline
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Post: #3
RE: Jumping voltage
You've got an incorrect wire there. An EFIE doesn't jump around like that on an oxygen sensor signal wire. The only thing that will cause that, is if there is something else going on with that circuit (the wire you've tapped into). It would have to be causing the voltage to jump around.

Note, it's also possible you have an AFR (Air Fuel Ratio) sensor, not an oxygen sensor. They look the same and have 4 wires. But if so, the signal wire will be at about 3.3 volts or 2.8 volts to ground, not between .3 and .8 like an oxygen sensor.

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06-12-2008 02:26 PM
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colchiro Offline
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Post: #4
RE: Jumping voltage
Toy, you need to read the voltage between the red and black terminals on the deluxe model or the white and green wires. That voltage should be stable. Measuring either wire to ground will jump around a lot.

Rick

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06-12-2008 03:01 PM
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toytech01 Offline
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Post: #5
RE: Jumping voltage
Thanks for the reply. I am measuring between the red and the black and it is jumping all over.


colchiro Wrote:Toy, you need to read the voltage between the red and black terminals on the deluxe model or the white and green wires. That voltage should be stable. Measuring either wire to ground will jump around a lot.
06-12-2008 05:07 PM
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mike Offline
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Post: #6
RE: Jumping voltage
Ok, the only time I've heard of that happening is when the EFIE is on an active circuit of a different type than an oxygen sensor. For instance if you have an AFR (air fuel ratio) sensor, it will do this. Other types of circuit will cause this. But not a narrow band oxygen sensor. It is only getting a voltage from the sensor side of the circuit, and the EFIE, under these circumstances won't jump around.

One way to ensure that it's not the EFIE itself causing the jumping voltage is to disconnect either the white or the green EFIE wire from your car. If the red/black port voltage is now steady, the EFIE is OK, and you're on a different type of circuit than it was designed for. Only if you still see the voltage jumping around with one leg detached as above can the EFIE be considered faulty. In that case, we'll need to arrange a return for repair/replacement.

But I think you'll find that the EFIE is steady when disconnected from that circuit.

Please look into this and let me know what you find.

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06-13-2008 09:09 PM
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toytech01 Offline
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Post: #7
RE: Jumping voltage
Well I cut the green wire and the efie went up slowly to about 450. I tested the green wire on the O2 side with it cut, and it showed .02v. Hooked up and tested on the green wire it jumps around the same as the test ports on the efie. So I guess that I can't use the efie? Should I just use an O2 extender or would that even work? I have a 5 wire MAF so the adjustable units don't work on that either. Any ideas?
Thanks again.
06-14-2008 08:41 AM
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toytech01 Offline
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Post: #8
RE: Jumping voltage
Adding to my previous post:
I just looked up my car for a replacement sensor and it lists it as a universal 4 wire Oxygen Sensor not an AFR? What gives? Could it just be a bad sensor? I don't have any check engine lights on.
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06-14-2008 08:48 AM
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syncromon Offline
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Post: #9
RE: Jumping voltage
I have not been able to get an EFIE to work on my vehicle (1989 Vanagon, w/'94 Jetta motor). I have a 4-wire oxygen sensor on mine also.
I have dual batteries, and the EFIE (and HHO) is powered by my spare battery. Its wired direct to the battery, with an inline switch, and using the vehicles body as the ground, I figured this would eliminate any stray noise or signals.
When reading the O2 sensor signal (green to ground), everything looks good. The signal after the EFIE to the computer shows the added amount of mv's as expected.
My main problem is the EFIEs added voltage will not remain fixed, it fluctuates with the RPMs. It does stay steady if I hold the RMPs steady, but the values are different at every RPM...when driving at 3500 RPMs the reading might be 150mv, if I speed up the reading drops, if I slow down the reading goes up...at an idle it will climb to over 250mv. I have the EFIE wired so I can turn it on with the engine not running. It will climb to its set point as expected, but when I start the vehicle it will climb even higher. I have seen other strange readings, but they are random, and I have not been able to figure out a pattern...occasionally the EFIE reading will drop when climbing a hill (under load), but it does not do that consistantly.
Mike has been great about replacing the EFIE, but in my case I suspect something fishy with my vehicles computer, it does have some signs of tampering, and hard to figure out what they did when the engine conversion was installed.
I would try different power sources for your EFIE, maybe a different ground (might eliminate any noise or stray signals), and double check the O2 sensor connections and readings, I have been reading others experiences to see if I can get any new ideas to try on my vehicle. good luck!

Syncromon
toytech01 Wrote:Adding to my previous post:
I just looked up my car for a replacement sensor and it lists it as a universal 4 wire Oxygen Sensor not an AFR? What gives? Could it just be a bad sensor? I don't have any check engine lights on.
Thanks
06-14-2008 09:19 AM
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mike Offline
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Post: #10
RE: Jumping voltage
syncromon, that's a bad EFIE. A healthy EFIE will not do that. If you bought it from me, then please PM me to get it replaced. If you got it from someone else, it needs to be taken care of.

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06-15-2008 12:31 AM
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