Get a mtx-l and run it with the serial output wire instead of 0-5v output, it will be more precise and faster signal

i had a aem a while ago with 0-5v ouput and the ecu didnt show the same reading as the gauge

switched to a psb-1 and its been good since

 

My gauge shows about 1-2 points richer than the 0-5 volt output.... I think the next step is changing the wide-band. Car just doesn't have that clean hard pull feeling. At least i will now have 2 back up LSU 4.9 sensors...

 

The 0-5v outputs tend to be really poor at translation. They are very much affected by any ground plane differences and can read way off depending on how they are hooked up. CAN or serial is a lot better as you get what the controller sees...
I always found having 2 AFR gauges a PIA... They never totally agree and you don't know which to believe. We use an NTK sensor on the dyno and I have the ECU running a Bosch 4.9... for the most part they agree if you allow for the latency for the different locations. I'm not sure what would be best for you to use... I think you have to pick one.... replace the sensor and use it... I would think the ECU run sensor should be the best

I find EGT's work well for picking up something strange happening. The values will change significantly enough that you will see it and start looking around

 

Well ordered the new MTX-L WB gauge and kit with 4-pin to 2.5mm jack cable from Summit for $167 shipped. Should be here Wednesday.

Pouring back through my logs on post 632, I had a nice clean hard pull at 20-24 psi at ~12:1 AFR, 11.0+ MPH/S acceleration.

I will replace the prosport wideband with the MTX-L which comes with another new LSU 4.9 sensor (will now have a new backup and a working backup). I'll use the serial cable to jack directly into my select ECU with digital output and log some things without modifying my fuel tables to see how far off things may have gotten. I hope I was just going 1-1.5 points richer than my wide-band sensor was reading causing rich misfires... We shall see...

 

I wouldn't feel too happy at 12.1 @ 24psi....

Just saying 😐

 

I think he is on e85... anything above e50 and I wouldn't worry so much

 

I interpreted it to mean that gauge is showing 12.1 AFR, but the results and conditions from running a lower AFR indicates that the gauge is likely displaying an incorrect higher AFR value rather than actual.

 

Exactly this.

Gauge reads about 1.5 point richer than output signal.... Gauge will read 10.5:1 when the output signal from wide-band reads 12:1. Any richer than 12:1 on the ECU signal and the gauge is buried around 10:1 (lowest display).... Its only the past few months that this drift has occurred and its getting worse. Some of these parts have been on this car for 5 years already...

 

So basically you don't really know what the AFR is? You have much more risk tolerance than me 🙄

 

don’t be jealous

 

Really.... 😏

 

Has anyone actually hooked up a MTX-L to a Adaptronics Select? The manual says to hook the 2.5mm jack into the "Serial In" .... But on the Select unit there is only a jack for "Phone" and "Serial Out".... I could hook it back up to "Pin1C" but this would be another analog signal, which defeats the purpose of buying this sensor....

EDIT - NM, I found the Serial In. I may have one of the first units because the "Serial In" is not labeled on the case and is kinda hidden...

Also the 4 pin to 2.5mm cable is only 4 feet long and will be about 6 feet short of running through the dash and engine compartment....

 

you must gave bought the powersports version, the other has an 8 ft cable (10 ft overall length)

hopefully you also bought the newer “plus” model too

 

Got the new sensor in and wired into the ECU. Did a few pulls and it looks like my A/F was good the whole time between 11.2-11.7:1. Its like no matter what, once I bet up around 6k RPMs, it misfires and loses all power due to something interfering with the ECU.

I am running out ideas here other than going back to the D585's.... On the positive side, the new A/F gauge itself is way more accurate and less bouncy....

 

Not one to give up, I leaned it out slightly in the upper RPMs to see if the misfiring/sensor issue would go away. Some positive news, I was able to take it up to 7,700 RPMs with no real events.

I think the next move may be to put some yellow heet in with my boost juice to dilute out the water and see if that helps. Also, it almost impossible to get above the 11.0 MPH/S acceleration unless I open the wastegate....

3,500-7,700 RPMs
43-97 mph in 3rd gear
21-25 psi
MAT 96-125F
E40 Fuel
Acceleration 10.7-11.2 MPH/S

 

Nice comparison here. I disconnected the waste-gate pipe from exhaust and welded a metal plug in a v-band fitting and connected it to the exhaust and let the flex section of the pipe aim towards the ground.. I will be able to switch back and forth between open and recirculated gate now in about 10 minutes.

Interesting enough, I made no changes to the tune from the previous run (shown above).

The difference of venting the waste-gate and freeing up the down-pipe volume behind the turbo.... Was hitting soft boost cut between 27-28 psi so it ruined a few of my runs. Hard cut is set to 28 psi.

Waste-gate Duty Cycle 51 - Boost 20-25 (recirculated), Boost 24-27 (open gate)
AFR the same because the VE table adjusted for the added boost
Acceleration (depending how its calculated) - 10.7-11.2 MPH/S (recirculated), 11.1-11.7 (open gate). Looks of happened to pick up about 0.5 MPH/S with the open gate, most of its likely the additional boost but it felt smoother. Less back-pressure on the whole system for sure.

Also a positive, since the 50 mm gate can control boost much better with less back pressure on it. The boost line is less jagged, and the computer seems to be able to output the fuel in a more linear fashion. All of the lines are much smoother...

Looks like I will have to rate boost cut to 30 psi . Looks like ii'm running out of injector though... If anyone has a line on some FIC 1650s they are selling let me know. Moving to a 1000/1650/1650 setup should give me more room to grow with higher ethanol percentages...



Just a excel of the same 3rd gear pull (2 seconds from 67.8 MPH to 89.4 MPH )

 

you probably need a pair of 2000s instead to support full e85.

 

Maybe just go straight to the ID 2600's and end this charade once and for all.

 

 

Bah, just when I thought the problem was gone....

On a real strong pull the ECU cut ignition at 6,500 saying I hit a rev cut. My cut is set to 8,200..... The RPMs were all logged correctly. Maybe this is a software of ECU problem that is causing these random issues. Back to the drawing board. I bought a used engine harness off ebay and plan to go over every inch of it and swap it in. Maybe a firmware update...

 

Do you have a throttle problem? Looks like the throttle closed before the rpm dropped?

 

No the throttle was 100%. Here is a easier readout of the event. I am positive this all has to do with coil interference on the harness/sensors or ECU. This never happened with the D585 coils. These anomolies will happen 25%-75% of the time depending on the day.

The previous pull was great. Everything is smooth until 820.437 seconds, At that very second the ECU thinks i'm exceeding rev-limit at 6,500 RPMs even though its set to 8,200.... The car cuts ignition, which dumps un-burned fuel in my exhaust. The resulting knock reading is noise from the fireball shooting out of my exhaust. The knock later on is also from lifting after the first ignition cut. Keep in mind that the whole table below only covers 1.5 seconds.

Also, the P2 injector jumps from 31% to 89% duty cycle. Air fuel goes from 12:1 to 10.8 almost immediately. There is no reason why the P2 injector should have received any signal to do this from the ECU, which is why this has to be a electrical/ground/coil issue...

My plan is to swap the main engine harness and make sure every single wire is perfect. Also when installing i'm going to do everything I can to keep all the coil and ignition wires separated the best I can from all the other main harness leads.. Right nows everything is in one big loom stretching from the motor to my ECU box...

 

I had issues with mine with ESS wiring and coil location that resolved when I moved the coils and rewired the ESS wiring to a different location. I have a standalone and a separate harness though... and a FC type sensor.. so a lot is different. My only worry would be making sure that the only stock wiring you are using for the IGN1a coils is the trigger wires... otherwise I could see issues from that.

 

New harness is in, I found a few issues with the old one. I also found that I had a vacuum leak on the UIM.

I made sure to get both harness grounds snugged up on the rotor housing.

I did about 4-5 WOT pulls through the gears and no sign of hesitation or ECU/sensors issues.... I was only on 17-20 pounds for the testing though. I feel like the issues may be behind me now, Time to crank it up again and hopefully it all keeps together....

Acceleration through 3rd gear 9.5 MPH/S at 17-20 psi... I added some fuel for safety above 6500, will lean out now that everything seems normal.

 

In my short experience vacuum leaks appear to be the bane of FI systems. It's taken me some time to sort out avoiding &/or eliminating them... particularly as you increase boost. And I'm only running ~13 psi. I imagine it's quite a task running mid 20s psi.

And hands down she performs better leak free...even at a little lower boost, than with even a small leak while pushing the turbo harder.