Need some help with EBV sensor

I've got a SP dongle here somewhere, but I had some serious problems when I installed it, until I figured out that whoever made it shorted the VREF pin directly to the ground pin (the PCM didn't like that for some reason /ubbthreads/images/graemlins/eek.gif). I had some VREF voltage issues after that, but I can't say for sure what caused it. The "dongle" is just a connector with a couple of resistors wired as a voltage divider, so the PCM sees a constant voltage. If I have to I'll just cut the connector off the harness and hard-wire in a couple of resistors. Don't think I'll be going back to the stock turbo any time soon /ubbthreads/images/graemlins/biggrin.gif

I think I'll plug the manifold, leave the sensor connected to the PCM, and ditch the metal tube (like HnH suggested). If that doesn't work I'll figure something else out.

I was concerned 'cause I thought I'd read that the PCM will de-fuel the motor if the backpressure was too high, as if the EBV was stuck shut for some reason. Can anyone confirm that?

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OP - I asked a question a long while back about what exactly the EBPV sensor had input on or what engine controls the EBPV had "influence" over. I got alot of intellignet answers that all boiled down to 1) it influences alot of engine parameters and 2) nobody knew all of what it influenced.


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This is directly cut-and-pasted from a sponsor's website:

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Do you have a modified truck or a bad Exhaust Backpressure Sensor?

Did you know that when you throw an Exhaust Pressure Sensor code, that your truck will defuel on top just like an overboost code? Yes it can and does happen. The exhaust backpressure sensor when a reading of 45PSI or more is achieved will store a code and remain in a 'defueled' mode until the next drive cycle. If your sensor is back or you have a really hot chip, this code can get thrown nearly every drive cycle. This costs you top end boost, and power since the truck isn't fueling as it should.

[/ QUOTE ] To see the rest of the quote, Click Here.

I've been told by several "Powerstroke-Intelligent" guys that the above quote is true, the PCM WILL defuel the motor at high back-pressure as a fail-safe strategy. In thinking about it, it makes sense. My original concern was in disconnecting and removing the EBV sensor, or at least removing the exhaust line and leaving the sensor open to atmosphere. So far, no one has been able to confirm that doing this will affect performance. I tried an experiment today that gave me some answers:

I cut the end off of the tube and hammered it closed, brazed it, and put it back on the manifold port to cap it off. I left the sensor open and plugged into the harness, so basically it is reading atmospheric pressure. I then drove the truck to the fittings store to pick up some parts. The truck was very sluggish, slow to spool up, boost was lower. I almost thought I had the chip in "stock" setting, but it was in the same setting as before.

I found some fittings that will allow me to connect the sensor to the MAP sensor line, which will allow the sensor to see a 1:1 boost pressure. With the QSSB turbo, this should be pretty close to the backpressure I was seeing before I capped off the EBV tube. As I said originally, this was what Dennis told me to do in the first place, so props to Dennis /ubbthreads/images/graemlins/biggrin.gif. I'll do that in the morning and drive it again to see the difference, and I'll post the results.

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Scanning thru this, I see at least one person who has had trouble with a product of ours...but we never have seen it back for replacement....if it's bad we'll fix it. The product is designed to solve the EBP code not the EBV codes.

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Not really sure if you want to go there. . . I tried to contact you a couple of times about it, but I'm still waiting to hear back. It's been a few years, so I'm sure you've forgotten about it /ubbthreads/images/graemlins/wink.gif