DaLorenve will need to detail all, since he demands that from everyone else.

Karl, have you received your repaired ECU yet ?

Will be interesting to see if the MPG issue gets resolved, hopefully you can articulate what exactly was found to be wrong with the DME?

Update...

ECU should depart CA from Systems Consulting for Miami tomorrow.

When I receive it, am installing new tie rods. This, given the recently found worn passenger side unit. While this seems to have nothing to do with the mpg given the test done with Dean's ECU, I want it removed from the equation. This replacement has not been done while the car sits idle as doing so in my condo's parking garage... car up in the air as is needed would draw unwanted attention. To get stuff like this done, I drive off premise to a spot I like to work at---this is condolife.

Then onto city & highway mpg runs. Double up the mpg runs for confirmation. Of course I'll post mpg results along with what Systems Consulting accomplished with the ECU when this info is in hand.

.

Just as a reference, today I drove 301 miles and used 11.07 gallons of gas. 27 mpg when driving mostly at the speed limit, 60 to 75 MPH.

Brilliant! :)
Ant.

Major delay on my part. LIFE gets in the way sometimes. Pardon me for this.

Systems Consulting has delivered on schedule as they promised. I'll get on with testing mpg this week. Plan is to post results over the weekend at some point.
.

Karl, now that you have the DME back and presumably have completed the transaction, can you tell us what exactly was wrong with the DME and what exactly was done to rectify it?

Systems Consulting ECU

My ECU went through various oscilloscope and chip tests. Fault is in the processor. With my ECU being a “rebuilt” unit from Vertex, and Vertex being a proven dubious source for ECUs, Systems Consulting chose to provide me an ECU that they alone have handled. My unit is cored. Within the ECU sent me from Systems Consulting, solder has been reflowed and anti moisture coating applied to the boards, these being to extend the units durability. Installed is a 358 eprom as an update. Unit was delivered to me several days ago as promised… pardon me as I’ve had to deal with distractions so mpg testing had to be set aside momentarily.

http://forums.pelicanparts.com/uploa...1753632738.jpg

http://forums.pelicanparts.com/uploa...1753632738.jpg


Test Results:

Systems Consulting ECU with 358 eprom:

Starts first crank
Startup idle holds at 1300 rpm…
Then drops slowly to 925 rpm within 60 seconds of start
Smooth idle - cold or warm
Strong pull to redline with zero hesitation

City = 19.001 mpg
Highway = 28.18 mpg

http://forums.pelicanparts.com/uploa...1753632877.jpg
http://forums.pelicanparts.com/uploa...1753632877.jpg

City


http://forums.pelicanparts.com/uploa...1753632877.jpg
http://forums.pelicanparts.com/uploa...1753632877.jpg

Highway


Fuel fills and refills were done as always: same station / same pump / same fill technique. Odo is proven accurate. There are a total of 4.3 city miles within the highway miles—distance between gas station and highway. Planned to install new tie rods and check struts for straightness before running highway but those had to be postponed for a few days.


Innovate wideband system: yanked

Innovate system has recently been serving up one malfunction after another. Latest issue: Whatever controller is at the end of the dual controller daisy chain, that end-controller’s trace line is always measurably higher than the other. And this higher line’s oscillation has a much greater amplitude than the lower trace line. Swapped controllers… same scenario albeit with the trace lines inverted. Innovate tech support = useless. Keeping reliable data going here has become too time consuming to deal with. LC-2 system is now shelved. Bungs are plugged. In contrast, LogWorks software has been faultless.



To each of you who participated with me in this journey, thank you! Thread discussions, PMs, emails, phone conversations, documents and images shared, and all the tests & checks suggested, the loaned ECU… I’m in great appreciation for each of you!

Dave, special thanks to you for arranging the ECU solution with Systems Consulting for me as you did. Great company to work with!

Systems Consulting… much admiration your way for taking on this ECU puzzle as you have done. Start-to-finish, your communications and handling of this matter has been World-Class. That I’ll not be plagued by “sleeping” faults given my ECU’s dubious origin… THANK YOU for covering that base, and for all that you’ve done for me. From the get go, it’s been a truly enjoyable association with you! And the ECU you provided me… STELLAR!

www.systemsc.com 310.545.3716

.

So Loren exchanged the unit because he couldn’t fix it? Is it only me feeling gaslit by the statement “the fault is in the processor” because the DME came from a dubious source?

The 8051 MCU can be swapped in 5 minutes if it really is root cause. Dave (aka Loren) makes that point in another DME thread. https://forums.pelicanparts.com/porsche-911-technical-forum/398595-calling-motronic-experts-ic-information-4.html#post12494177

The “upgrade” to the 28-pin chip conveniently runs all code from external memory to where any generic 8051 will do. So why not just swap in a new 8051?

He probably gave you a reworked 924 or 944 DME with non-911 compatible ROM code on the 8051 and kept your “core” to make it an early 911 DME for the next paying customer. The “reflow” nicely hides the other rework required….

Missed seeing this in the post (#270) by the OP?;

http://forums.pelicanparts.com/uploa...1753642359.jpg

So you're unaware that the 924 DME ECM uses RCA chips & NOT an 8051!

Did you miss seeing what the "rebuilt" core (see OP's post 176) looks like?;

http://forums.pelicanparts.com/uploa...1753642519.jpg

The replaced ECM has the later better fiberglass circuit boards, see the image in post #270.

Given that the OP had consumed so much time & effort with his "rebuilt" ECM, and to minimize any future problems, Systems Consulting just provided another better ECM.

Oh - did I miss the memo where the sheet metal covers are serialized to the PCB stack :rolleyes:

If you’re that standup guy you want to portray yourself then why not spell out what was wrong with the DME that led to increased fuel consumption. And if you don’t know then say “I don’t know” instead of first declaring it as “fault in the processor“ and now saying it’s due to a screw/nut instead of rivets in the heatsink.

Sadly these statements sink to the level of „…replaced an out-of-spec transistor…” and to me this is disrespectful to a community that wants to learn.

For more info, you need to call Systems Consulting, the number is on their website; www.systemsc.com

Great job Karl and nice write up and troubleshooting. You must have the most sorted 911 on the road now!

It is great you finally have normal fuel mileage. It just seems impossible that the vehicle can use that much fuel, and not blow black smoke.

I sure can't argue with the documentation you have provided, and I have to accept the proof you have provided. Welcome back to the land of normal fuel mileage!

Karl,

Congratulations on a nice new running car 😉

As a BTW, there was a recent Klassik ATS video that demonstrated the disconnect between a running air:fuel meter showing condition A, and a professional gas analyzer showing condition B at the same time. Condition A said the car should run fine, but it ran like scheiße. Once sorted and set per the professional gas analyzer the car ran correctly. Kinda puts one off on those chinesium a:f meters.

I have to admit to being curious as to why the original ECU was so far out of spec that it needed to be replaced, However; I am glad to hear that the OP [Karl] now has a great running car, with decent MPG.:)
Ant.

I’m still curious as to why all the data logs Karl took presented relatively ok AFR but the mpg was so off target and how the ECU being “out of spec” contributed to the issue.

I’m glad that Karl has his car back to where it should be but we still don’t have a REASON why the ECU was the culprit.

Was it a PW issue with the injectors? Was it some other monitoring loop? What fault in the ECU can cause the car to run fine but with low MPG?

This isn’t about pointing fingers, it’s about a massive thread that the whole community troubleshot being resolved so that the next person who has this issue can retrieve a solution and a cause for the issue.


Sent from my iPhone using Tapatalk

:)

yup,as ant, showdown too.... mentioned, maybe is a secret Loren does not like to share----kinda pointless thread than!!

Ivan