I just found this:
http://www.plxdevices.com/AppNotes/PLXApp013.pdf

It has a whole buncha MAP sensors w/ voltage to pressure value tables.

 

Do you think disconnecting the vacuum lines to the EGR valve will cause it to leak boost? According to the diagram below, there are two vacuum lines going into the EGR valve. One is from the solenoid and the other one goes directly to the intake manifold.

I'm not sure which line opens and which one closes the valve, but I would assume under boost, the valve would close. Otherwise, boost will leak straight into the exhaust. So I'm wondering if a disconnected EGR valve would blow open under boost.

 

Not to sound silly, and i dont plan to do it... But with a MAP , can you know vent BOV's to the atmosphere? thought that was one of the required mods other than an AEM ems. ? thanks, just curious

 

Yes you can vent your BOV right now. The MAP sensor just replaces the USDM MAP sensor and it has a larger range. You will still be running a MAF setup on the car. To convert to speed density you also have to have an AIT sensor.

 

Venting to atmosphere will still confuse the ECU though and cause it to dump fuel when the BOV is venting.

 

See the lines going to the EGR valve itself? I plugged those two lines.. If I took them off anywhere else It seemed like I introduced a vacuum leak.

 

There is way more to converting to speed density.. you can use a third party device to use a AIT and MAP sensor to reproduce the signal. additionally you'd need Throttle position, RPM, as inputs to properly calculate VE to reproduce a value the ECU can use.

One of the members of aktivematrix has been researching two options, there's plenty of room in the stock ECU for tables associated with a speed density conversion within the ECU itself, and another option (that he's much closer to testing) is using an analog MAF sensor (Ford Sensor similar to what I use in my blowthrough setup) This is off into the future, but I wouldn't be surprised to see alternatives to the Karmann sensor turn up in a year or so that won't require converters.

 

This is very promising and outstanding to say the least. I do alot of obd1 tuning on honda's and the lengths they have gone to integrate external map sensors, more rpm and load sites, 2 step w/ antilag, etc. with just the obd1 ecu. Keep up the good work.

 

Jack,

I should have been more specific. I traced the vacuum lines from the EGR valve back to the throttle body. So I just disconnected the two lines from the throttle body and capped them.

My concern is the EGR valve itself. I am wondering if boost will blow the EGR valve open slightly and cause a leak. I have an old EGR blockoff plate from my DSM. I'll do some before/after logs to see if there's any difference in boost levels.

 

I pinch sealed the lines at the throttlebody. It would idle with the USDM MAP sensor, but still would not run with the JDM sensor. Didn't try to drive it in this condition.

 

I'd actually be curious to know.. It technically shouldn't actually blow open or anything with no pressure on it, but I was planning on using a blockoff myself (I'm using a stock intake manifold for the time being, but have an aftermarket manifold going in soon, the goal was to get everything to work properly with the stock sensor and solenoids, then add a 3 bar MAP sensor, make the mods necessary for it to work without throwing codes, then swap in the new manifold.

 

the exhaust will not push open the egr on its own. it would take a large amount of pressure on a small surface area to push open the valve. like trying to start the car with a potato in the tail pipe, or in our case a grapefruit. but then an egr popping open a little is the least of your concerns

 

hey jack , do you know how the jdm map sensor would trigger egr codes? it is my understanding that the ecu uses a logic chain by watching engine rpm for a drop when opening the egr valve to determine proper egr function.

Edit: I am incorrect on the egr statment, it does monitor map

 

bez_bashni found the MAP translation table in the Evo 9 ROM, and I got the JDM MAP sensor to work in my USDM Evo 9 with no mods to the EGR system. The only mod to the engine is to replace the UDSM MAP sensor with the JDM MAP sensor. Here is my post in the other thread:

https://www.evolutionm.net/forums/sh...52#post4074452

The group buy is back on if anyone is interested. As long as the current exchange rate stays reasonably stable, the price will be no more than $125.00 shipped to your door if I can get 10+ buyers. If you are interested, please PM or put your name on the signup.

JDM Evo IX map sensor group buy signup
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That thread seems very promising...if i didn't already have an LMA-3 3 Bar map sensor i would hit it!!!