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Thanks Don. Very interesting stuff. I was wondering what the 2000 hrs would equate to in mileage on a car. So for example I would be doing a rebuild every 30,000 miles? I know that's very subjective but was just interested in some sort of comparison. I guess with the info you have provided I can think about that while I watch the cricket this arvo.

The post-overhaul ground test tends to be brief. Aircraft engines are air cooled, so running them on the ground for too long can do damage.
I had wondered that but I see aircraft sitting on the infield at throttle for considerable time. Are they all air cooled?
 

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Discussion Starter · #482 ·
30,000 mile overhaul? No comprendo.

2,000 hrs X 175 MPH = 350,000 miles. That would be pretty good for an old Volvo, and inconceivable for an Alfa.

Most general aviation, ie “small” airplanes are gasoline and air cooled. Once you cross the million dollar Mark you might have turboprop. Jets start at several million.

In 1979 I paid $15,000 for mine. It was 15 years old.
 

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30,000 mile overhaul? No comprendo.

2,000 hrs X 175 MPH = 350,000 miles. That would be pretty good for an old Volvo, and inconceivable for an Alfa.

Most general aviation, ie “small” airplanes are gasoline and air cooled. Once you cross the million dollar Mark you might have turboprop. Jets start at several million.

In 1979 I paid $15,000 for mine. It was 15 years old.
So as a generalization the comparison would be like doing 100,000 highway miles in a car.

Does the prop provide enough cooling to run an engine on the ground?
 

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Discussion Starter · #484 ·
So as a generalization the comparison would be like doing 100,000 highway miles in a car.

Does the prop provide enough cooling to run an engine on the ground?
still not grasping your question.

In my reasonably fast airplane, I will travel 300,000 + miles between engine overhauls. Possibly 400,000.

At the low power settings appropriate for taxiing, the prop provides sufficient cooling. Our earlier conversation was with respect to post-overhaul testing, and that will include full power runs. Typically, the prop will not provide sufficient airflow for full-power operations.
 

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Discussion Starter · #485 ·
I’m baaaaccck.

So, after I got the monkeyed connector sorted out a while back, I got a good link with Multiecuscan, and was able to sort out the variable idle. After that, all good until I blew up the engine.

Car runs fine with the cheap, junk yard engine from the U.K., but the idle needs a reboot.

Couldn’t get a synch today. Tried everything I knew, rebooting everything I could. To be clear, I got a quick Bluetooth link, but Multiecuscan could not link with the ECU. Normally, this would be a problem with the adapter or cable, but none of that was changed during the engine swap.

All of the connectors on the harnesses hooked up, and I didn’t see any remaining, un-mated connectors.

Anyone with tips on what to look for in the engine bay?
 

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Nothing you wouldn't have thought about Don but check the main wiring loom plugs, make sure you didn't bend a pin over or something silly. Check power at the obd plug.
 

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It has to re-learn the proper setting. AR drive by wire has some odd reset routines. You should be able to search up the recommendation. As I recall, disconnect power, start and let idle without touching throttle for a long long time, shut off for a long while. Then, enjoy it.
 

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Discussion Starter · #488 ·
It has to re-learn the proper setting. AR drive by wire has some odd reset routines. You should be able to search up the recommendation. As I recall, disconnect power, start and let idle without touching throttle for a long long time, shut off for a long while. Then, enjoy it.
Mine has a cable throttle, not electric throttle. But that’s not really my concern.

I had gone through an iterative process of multiple resets with the previous engine, and arrived at a well behaved idle. I get the impression the Motronic is learning the new engine, because the idle behavior has been changing. That’s why I didn’t rush to hook up the OBD and tinker. My problem now is the inability to connect with the OBD.

As we observe in aviation, if the engine quits,, what was the last thing you touched?

That would be swapping engines.

However, I reused the intake stuff; throttle, MAF, etc. I found several leaks and other issues, so it makes sense that the Motronic really ought to be reset, and let it learn from a known baseline.

Question is, which wires or pins or connectors or relays or fuses might be causing the lack of OBD-Multiecuscan to not connect?

With the previous engine, I couldn’t get a hookup because someone had reordered the pins in the car’s connector, presumably in an effort to use an incompatible diagnostic system. I did some research and bought the recommended software and Bluetooth adapter, and after resetting the connector pins where they belonged, got an immediate synch-up. Now, after engine change, no connection.

I am getting a quick Bluetooth synch, just nothing after that.

I can drag out all possible manuals, but suspect somethings amiss with a single wire connecting to the ECU. AH, BUT WHICH WIRE?
 

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I could not get my 156v6 to connect to Multiecuscan until I bought the 3 coloured adapter leads ...
Pete
 

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Discussion Starter · #490 ·
I could not get my 156v6 to connect to Multiecuscan until I bought the 3 coloured adapter leads ...
Pete
I sort of followed your thread with your connection issues. Problem is, mine connected quickly before I stuck in a different engine. Same ECU, and the engines runs quite nicely.

My BT adapter description specifically stated it would work with the Alfa Motronic in my car, and did.

Gotta be something I bumped during extraction or insertion.
 
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Here's how the T20 Plug wiring connects into the rest of the systems.
View attachment 1646738
Here is a generic OBD2 Pin Out
View attachment 1646742
Notice how the Alfa unit has the same +12V on pin 16 and ground on pins 4 and 5. The Alfa ECU is on Pin 7 - ISO 9141-2 K-Line and all other Alfa connections are Vendor Option pins.

If your +12V is really on Pin 15 then you'll want to get that fixed since no OBD2 connector will work.
Hey Don,
Here's the OBD2 stuff from a while back. I assume your bluetooth adaptor is getting power but you can probe pin 16 for constant 12V power and pins 4 & 5 for ground. If those are good then you should check continuity from pin 7 to your engine ECU pin 11.
If you don't get continuity from pin 7 to ecu 11, then look for connector G99b, pin 4 which is the break between the engine and the dash harnesses.
 

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Discussion Starter · #492 · (Edited)
Hey Don,
Here's the OBD2 stuff from a while back. I assume your bluetooth adaptor is getting power but you can probe pin 16 for constant 12V power and pins 4 & 5 for ground. If those are good then you should check continuity from pin 7 to your engine ECU pin 11.
If you don't get continuity from pin 7 to ecu 11, then look for connector G99b, pin 4 which is the break between the engine and the dash harnesses.

Excellent! I probably could have patrolled my own thread for this info, but getting lazier as the big seven-0 approaches.

Now, I just gotta find the ECU.
 

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Discussion Starter · #493 ·
Hey Don,
Here's the OBD2 stuff from a while back. I assume your bluetooth adaptor is getting power but you can probe pin 16 for constant 12V power and pins 4 & 5 for ground. If those are good then you should check continuity from pin 7 to your engine ECU pin 11.
If you don't get continuity from pin 7 to ecu 11, then look for connector G99b, pin 4 which is the break between the engine and the dash harnesses.
It's starting to warm up enough I can play with the GT outside. Shop is consumed with paint booth at the moment.
anyway..

"ECU". There are several. Should I search out the "Injection - Ignition" ECU, or is there a sort of Master unit that captures and controls all of the OBD codes? If so, where might it be?
 

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Don I'm not sure if I am answering your question or just stating the obvious. The engine ecu will store all the codes related to engine parameters. The body control module computer stores codes for things like the dash, A/C ect. ABS computer for ABS codes ect ect. I think each computer stores its own codes relative to its function however they need to communicate with each other. Your car has an early cam bus system. I think if you google cam bus it might make more sense.
 

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OBD2 was designed to join all of the various ECU together into a single diagnostic port. Your software/hardware combination is physically pinned to read multiple ECU depending on what is present at the car side connector.

In your case you'll be looking for the engine ECU which is likely called 'injection, ignition'

Your google will search should be CAN bus (not cam bus). CAN bus is a fancy way of saying serial bus with an automotive protocol.
 

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Discussion Starter · #496 ·
OBD2 was designed to join all of the various ECU together into a single diagnostic port. Your software/hardware combination is physically pinned to read multiple ECU depending on what is present at the car side connector.

In your case you'll be looking for the engine ECU which is likely called 'injection, ignition'

Your google will search should be CAN bus (not cam bus). CAN bus is a fancy way of saying serial bus with an automotive protocol.
I'm intending to confirm the continuity of OBD port pin 7 to ECU pin 11, as babycar suggested. However, there are many "ECUs". I'm guessing he meant the ignition-injection ECU, but hate to leap to assumptions.

My idle behavior, while not life destroying, could be better. I resolved this with a series of resets on the previous engine, but can't get an OBD connection since I swapped engines. I've done a quick review of all of the connections on the engine itself, and see no problems.

I do get a Bluetooth connection between my IPad using Multiecuscan and the adapter hooked to the OBD port. But, nothing beyond that.
 

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Discussion Starter · #498 ·
I dug back into the 916 yesterday, trying to get a synch with my Multiecuscan. Alas, no bueno. Tried every variation, reboot, and pin-confirmation I could imagine. Idle continues to... change. And wander.

I'm also finishing up the repair of the first engine. Awaiting a few parts from Alfa Workshop.

As a part of that, I began studying the engine wiring harness on my shelf. I don't recall now whether the replacement engine in the car was installed using the harness it came with, or the one connected to the previous engine. They appear identical, and the dates on the tags are within a couple of months, and both say "P2", if that is meaningful.

I tried to locate the ignition/engine computer, which is described as being somewhere near the passenger footwell. No luck seeing anything like a computer, at least without tearing out the dash. Nope.

So, here I am.

I would have thought a flaw in the engine harness would simply give a fault code rather than prevent a scanner synch to the OBD. If the OBD communications line is direct from the computer to the OBD plug, why would an engine swap disrupt things?

There is a picture/schematic in the manual that depicts two gang plugs connecting to the engine computer. This depiction looks like the two gang plugs on top of my throttle body. Is the computer under there? I wouldn't have thought a hot and vibrating location was a good first choice for microchips.

I don't mind buying a hard-wired adapter, but my BT to IPad worked a treat previously. I no longer have a Windows-based laptop, so not sure what my options are.

Yes, I'm getting a good power-up and link to the BT adapter. Just no synch to OBD.

Argh.
 

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I dug back into the 916 yesterday, trying to get a synch with my Multiecuscan. Alas, no bueno. Tried every variation, reboot, and pin-confirmation I could imagine. Idle continues to... change. And wander.

I'm also finishing up the repair of the first engine. Awaiting a few parts from Alfa Workshop.

As a part of that, I began studying the engine wiring harness on my shelf. I don't recall now whether the replacement engine in the car was installed using the harness it came with, or the one connected to the previous engine. They appear identical, and the dates on the tags are within a couple of months, and both say "P2", if that is meaningful.

I tried to locate the ignition/engine computer, which is described as being somewhere near the passenger footwell. No luck seeing anything like a computer, at least without tearing out the dash. Nope.

So, here I am.

I would have thought a flaw in the engine harness would simply give a fault code rather than prevent a scanner synch to the OBD. If the OBD communications line is direct from the computer to the OBD plug, why would an engine swap disrupt things?

There is a picture/schematic in the manual that depicts two gang plugs connecting to the engine computer. This depiction looks like the two gang plugs on top of my throttle body. Is the computer under there? I wouldn't have thought a hot and vibrating location was a good first choice for microchips.

I don't mind buying a hard-wired adapter, but my BT to IPad worked a treat previously. I no longer have a Windows-based laptop, so not sure what my options are.

Yes, I'm getting a good power-up and link to the BT adapter. Just no synch to OBD.

Argh.
Hi Don. Glad you haven’t flown to the jungle just yet. I think the ecu is up under the dash. Try removing the glove box. Not sure if sighting the ecu is going to help however.
Can’t really offer anything you wouldn’t already know but just a general comment. Manufacturers do indeed place the ecu directly onto the engine these days. I would assume it’s to minimise the amount of wiring used in the manufacturing. Even my 2003 147 has the ecu bolted to the intake manifold.
 

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Oh and just to repeat what I have said many times. And it’s not to be a smart *** but just to highlight my point. Some of these early cars are a utter pita to try and connect with. Many Italian cars of the same vintage are the same. If anyone can explain that I would like to know but I tell you first second and third hand from within the industry that is the case.
 
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