85 IROC TPI 1227730 conversion from 1226870

[zaut]

I analyzed my first data log. Did a lot of excel work, pivot tables averaging ETC. I came up with a nice table VE% tables. I did the smoothing as you suggest. What a nice feature. Then I took the car out for another run and nothing changed. The BLM stayed around 108. So after scratching my head for awhile, I started looking into other data besides MAP, RPM and BLM. It turns out my MAT is stuck on 61.4F. It never changed. I figure MAT plays a huge role in the fuel delivery considering Boyles law. So I trouble shoot the MAT circuit. All is fine. In fact I can unplug it and the temp is still 61.4F. Is my ECM bad, or is there a glitch in TunerPro? I am guessing on the ECM. Fortunately my junkyard EMC came with a warranty of some sort. Weather they have another one or not is a good question!
Thanks 34blazer. I'll look into the AXXD after I get the MAT issue worked out.

[34blazer]

check the wiring, make sure the +5V for the IAT is isolated by itself on pin F16, the ground can be redundant with the rest. read the link and you will see i was having the same exact problem. well i hope its as simple as that, because it took me almost a year to figure it out lol


http://www.gearhead-efi.com/Fuel-Inj...-options/page3

[EagleMark]

Well the MAT will through it off but 108 is a normal rock bottom rich BLM setting so unless you made big change it's still rich.

MAT should have 2 wires, one 5 volt reference and other to ECM. Check for 5 volt and see if data pin is in correct location on ECM.

Here's how to OHM check the sensor. CTS, IAT and MAT are all the same test.
http://www.gearhead-efi.com/Fuel-Inj...ostic-Test-CTS

[zaut]

Mark, I may have adjusted the VE% the wrong direction. For clarification, if I am running rich (low BLM); do I want to increase the VE% or decrease the VE%? My thought is if I increase the %, then the ECM calculates that I just put more air in, therefore more fuel. Therefore I should decrease the VE%. But that goes against my other thought that the high performance engine was designed to be more efficient at pumping air. So the VE% should increase. You can see I am perplexed! Bottom line is which direction to move the numbers. I increased them based off my second theory which my results say I was wrong, unless the MAT is clouding the issue.

[EagleMark]

Your dealing with the fuel VE, not air. If your rich, = under 128 BLM, reduce number (fuel), if your lean = above 128 BLM, increase number (fuel).

MAT has a table and adjusts fuel acording to tempreture of air. Tempreture of air changes so does density. You could 0 out that entire table for now until you diagnose and fix the issue and continue tuning VE. Actually it may be better to tune without MAT? Just thought of this and it's not a tested theory but MAT is a calculation that adjusts fuel VE table depending on air density... this goes back to not messing with anything (except turning off things that adjust VE like EGR and PE and probably MAT) until VE tables are correct because everything is an adjustment from VE table.

[Six_Shooter]

To reduce fuel, reduce the numbers in the VE table.

The MEMCAL you're using, is it a RWD 3.1 or FWD 3.1 MEMCAL?

[zaut]

Mark, I definately moved the wrong direction.

Six shooter, the memcal was from RWD 3.1. I do have the jumper correct now. I just cant use the knock circuit. I ordered a 16151348 or AUJP from Autozone yesterday. They sell remanufactured ones. Hopefully it is correct.

34Blazer, I think I am following in you exact footsteps. I checked, double checked, triple etc the wiring. I have the tan 472 circuit connected to F16. I did a shorts test to every other circuit in the ECM and found no other circuits connected to that wire. There was a slight difference in my wiring to the diagrams for the 730 in the ground circuits (452 and 470). The 452 circuit for the old wiring included the ground for the MAT, CTS and TPS. There was no 470 circuit. In the 730 wiring, the 452 circuit only connects to the CTS and TPS. The 470 circuit connects to the MAT and MAP sensors. At first, only connected the new 470 to the MAP because pin B5 (452) and B6 (470) are connected together internal to the EMC. After these issues, I made the 470 and 452 circuits match the diagram by moving the CTS ground with the MAP. My MAT is still stuck on 60.7F. And this is my second EMC. So did you find other wires connected to your 472 circuit? I read your post from when you went though this and you said “i mixed up the +5V leads, TPS was at F16 and vice versa.” Using a meter I have confirmed several times that the lead I plug into F16 is going to the MAT sensor. The MAT sensor is reading the correct resistance for the temperature. What is really driving me crazy is I can unplug the wire at F16 and the ECM still reads 60.7F. So I wonder if there is a glitch in the $8d ADX file I am using.

[Six_Shooter]

One other think I forgot to mention is that you will need a different knock sensor, one matched to the displacement ( as close as you can get) and the ECM, so a 1990 to 1993 5.7 in an F-body would be as close I know of.

The reason for a different KS, is because the sensor resistance is different between the systems that used the external knock filter and the internal systems.

[34blazer]

Mark, I definately moved the wrong direction.

Six shooter, the memcal was from RWD 3.1. I do have the jumper correct now. I just cant use the knock circuit. I ordered a 16151348 or AUJP from Autozone yesterday. They sell remanufactured ones. Hopefully it is correct.

34Blazer, I think I am following in you exact footsteps. I checked, double checked, triple etc the wiring. I have the tan 472 circuit connected to F16. I did a shorts test to every other circuit in the ECM and found no other circuits connected to that wire. There was a slight difference in my wiring to the diagrams for the 730 in the ground circuits (452 and 470). The 452 circuit for the old wiring included the ground for the MAT, CTS and TPS. There was no 470 circuit. In the 730 wiring, the 452 circuit only connects to the CTS and TPS. The 470 circuit connects to the MAT and MAP sensors. At first, only connected the new 470 to the MAP because pin B5 (452) and B6 (470) are connected together internal to the EMC. After these issues, I made the 470 and 452 circuits match the diagram by moving the CTS ground with the MAP. My MAT is still stuck on 60.7F. And this is my second EMC. So did you find other wires connected to your 472 circuit? I read your post from when you went though this and you said “i mixed up the +5V leads, TPS was at F16 and vice versa.” Using a meter I have confirmed several times that the lead I plug into F16 is going to the MAT sensor. The MAT sensor is reading the correct resistance for the temperature. What is really driving me crazy is I can unplug the wire at F16 and the ECM still reads 60.7F. So I wonder if there is a glitch in the $8d ADX file I am using.

well i found out the circuit still worked when i probed the F16 pin with Key on, tunerpro connected. when i probed F16 with the red dvom probe and the black to ground, the temp in the ADX jumped to 72*. so i took the upper intake off and dug around in the wiring and found the gray wire that was meant for the +5V to the TPS was connected to the IAT instead of the tan wire. switched them around and voila. try my adx, should work but will be limited since you arent using S_AUJP. should still show IAT temp though.


*edit* i physically traced the wiring to the IAT just to be sure, otherwise i wouldnt have known exactly what was wrong and still be fighting the issue lol

[EagleMark]

What is really driving me crazy is I can unplug the wire at F16 and the ECM still reads 60.7F. So I wonder if there is a glitch in the $8d ADX file I am using.

There may be a glitch in the adx. But since everything in S_AUJP is changed around in bin file it's a crap shoot if it will work with anything on your ALDL output.

Since you've gone this far you should continue to go where everyone else did and use S_AUJP Bin XDF and ADX. You'll end up doing it someday anyway...

Six Shooter is correct on the knock sensor. When you asked if you should use the 5.0L or 5.7L I told you the 5.7L as cubic inch is closer, but didn't realise you had a truck engine, I thought it was a F body engine...