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Discussion Starter #1
Greetings Folks:

Our Alfetta is being treated to an engine overhaul. It was purchased with a GoTech EFI handling the fuel and ignition management. As part of the rebuild, I am installing an O2 sensor in the exhaust stream. The sensor was part of an AEM-30-4100 UEGO Controller Gauge kit, which will (hopefully) be reporting on the mixture status while underway.

The price on these systems - which include the gauge, the sensor, and wiring - recently dropped to less than $220, making it quite the deal, IMHO.

The big motivator for the exercise was that the GoTech was installed running open loop, with no feedback. The AEM unit has a emulation output that will be presenting a standard narrow-band output 0-1v signal to the GoTech computer. My research has shown that a wideband is much better, but has historically required a pricy controller to implement.

I have little to share at this point, but I thought that as I go through the process I would document it here for anyone interested. If anyone on the BB has any suggestions, I'm all ears.

Photos below show:
1) Termination block for trunk battery cable run (battery was in engine bay)
2) Drilling out the front pipe for sensor bung,
3) Kit including a Painless 3-circuit fuse box ( fuel pump, GoTech, O2 sensor), the UEGO gauge, a remote starter solenoid and a 50A fuse for the alternator feed wire.
4) O2 sensor on car.

The relay-switched fuse box will replace the original set of components, which were fairly neatly installed, but not quite unified enough for my taste. When we lost the starter in Nebraska, everyone said I should use a starter solenoid, so here it is....

- Michael
 

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Discussion Starter #2
Greetings: The starter solenoid I bought seems a bit "too much". It's quite large, and is designed to totally eliminate the in-starter contacts, as it switches the battery cable feed. I will likely just add a relay to remove the full solenoid current from the dash starter switch.

Spent most of the day installing the exhaust. I obtained a used rear-of-bellhousing exhaust bracket from Highwood and had it powder coated. The Alfetta came with only 1 1/2 of the five exhaust mounts (rear-most and 1 of the two center doughnut pair)! All the hew exhaust installed was ceramic coated for durability. (Kudos to Gene @ Central CT Coatings

The O2 sensor's junction was mounted on the firewall as shown in attached pic. Two small holes were drilled to accept the socket's two plastic nibs and it snapped in place. The harness connector attaches here (upper part of assembly) and runs into the cabin to the controller/gauge. Left is the new power cable junction box, with trunk-mounted battery cable and starter cable. Smaller red cable feeds the original fuse box. Power for the EFI will be pulled from here, also. In between is a black wire that carries a good frame ground to be used by the EFI components. Also visible is the ground strap, just added. The car came with the front-mounted battery attached directly to the block with a solid cable....

- Michael
 

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Glad to see you making some progress on that car. You're the viking who drove that Alfetta cross country right?

Wasn't that the Alfetta JJ was selling late summer? Nice example from what I could tell & very nice color too.

Are you going to move the battery back to the rear (I'm assuming they are the same as GTV6, never owned an Alfetta)?

GoTech should be a good system once you get it sorted-out, though I am surprised at the state of install considering where it came from. Must have been a "proof-of-concept"?

Keep the updates coming! Also, what are your plans for the motor (if I recall, it was smoking quite a bit, yes)?
 

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Discussion Starter #4
Keep the updates coming! Also, what are your plans for the motor (if I recall, it was smoking quite a bit, yes)?
Greetings: Thanks for the encouragement, ToonRboy. Just what I need to get me into the barn tonight, as the daylight has passed working out of the HoneyDew Jar.

Our journey from Seattle was a wonderful experience. Although there were a few bumps, we did ride the Afetta all the way across!

While JJ was involved in the application of the GoTech, I bought it on eBay from a party removed from the work done earlier. The installation of the Gotech was first rate and well sorted out, but it was indeed a "proof of concept" and done on a tight budget - if 3 big ones can be considered tight. Spending any real coin on an Alfetta is very hard to justify. I'm getting along by doing the majority of the work myself.

The battery move is being documented on the BB at alfetta-gtv-rear-mount-battery-cable-routing]

and the engine rebuild at the tail end of our transcontinental recovery thread (see signature link)

- Michael
 

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Another good addition to an WB O2 meter is a vacuum gauge.

I have a 0-100kpa absol gauge mounted next to my O2 meter and by watching them you get a real sense of what is going on within your engine.

I found this more useful than a laptop and data logs etc.
 

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Discussion Starter #6
Greetings Brett:

OK, good suggestion. The goTech plumbing brings a manifold pressure hose into the cabin to drive the controller. Perhaps I could simply tee it off there?

- Michael
 

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I run a MS system and it has an on board MAP sensor so I've just simply teed off the line going to it.
This also puts the gauge down stream of the pulse dampening system which you will need if you have ITBs

The gauge I used was originally meant for a diesel and was calibrated 0 to 100 kpa (0 to 15psi). The MS system uses the range 100 to 0 kpa absolute (reverse of normal gauge pressure) so I removed the pointer and set it to 100kpa at atmosphere. This then gives me the same reading that my MS sees.
I'm an instrument technician so this was relatively easy for me.

The trick would be to use a gauge that is calibrated to the same scale as your ECU. That way you don't have to do any mental gymnastics.
 

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I've been looking at Innovate Motorsports for the wideband meter.Innovate Motorsports Wideband Air/Fuel Ratio Tuning
At the risk of sounding like an advert, I have an Innovate LM1 with the RPM adapter and I've found it to be the best way to tune AFRs, especially when doing it on a (quiet ;)) road. Doing a data logged run and being able to look at all the information closely and carefully is so much easier than trying to do it real time.
That and their Logworks software is excellent, especially the injector calculator that allows a Rev by Load log of AFRs and the ability to click on a cell and type in the desired AFR and it spits out a positive or negative correction percentage :D
 

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Discussion Starter #10
Brett and Duk: NOW you tell me!!!! Looking over the Inovate site, they do seem to offer a superior solution. I am comfortable for now, as my intention was to dip a toe into this subject by attempting to plumb in the closed loop feedback. The GoTech seems to be fairly well tuned, as it always started reliably (even when Kathy was back there pushing) and amazed me with how strong she pulled (the Alfetta, not the wife) up those 10,000 ft grades out west.

That said, I do expect that the engine rebuild and consequent increase in compression to encourage a retune.

As for the project, more time spent wiring in all the components, with nothing to display.

Oh, actually, there was an interruption yesterday at 5AM, and we had the pleasure of making a quick round trip up to Lowell, MA to greet our new Granddaughter! Neither of her parents can drive a stick, so I'll have to teach her.

- Michael
 

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Discussion Starter #12
Greetings: A bit of progress on the wiring. To better protect the entire assemblage, I added a BUS circuit breaker to the system. The breaker gets a feed directly from the battery connection box. On the AUX side, I connected the original feed to the main fuse box, the new engine management fuse box, and a power run for the relay for the starter motor.

The battery connection box on the lower firewall now has four wires: The big cable (0/2 ga) from the trunk & the short run over to the starter (4 ga) on one stud, and the Alternator and new breaker connection (both 8 ga) on the other stud.

Much time expended getting the terminals on securely and applying the harness wrap material.

I chose a 2 1/16" VDU vacuum guage, and now I have a question about the manifold vacuum circuit. The current installation simply joins all the individual intake manifold runs into a common feed to the GoTech unit. Should there be check valves in those circuits to insure there are no vacuum losses to the closed valve runs?

- Michael
 

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You need a restrictor, or restrictors, and maybe some sort of capacitance.
Some guys use a single restrictor and a fuel filter to act as a capacitor.
I use 0.6mm mig tips from each TB and a final one in the line going to the MAP sensor, with no capacitor
This gives me a reasonably smooth signal without adding too much lag.
I may all depend on what your ECU can do filtering wise.

Try a few combinations and see what works best for you.

Oh the joys of ITBs :rolleyes:
 

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Discussion Starter #14
You need a restrictor, or restrictors, and maybe some sort of capacitance... Try a few combinations and see what works best for you.

Oh the joys of ITBs :rolleyes:
Thanks for the suggestions! My head is swimming with all the concepts, however. Getting to the "what works best" decision presumes I would know what I'm looking for. The MAP signal is but one of several that feed suggestions to the ECU. Where does the MAP's input show up in the power curve or drivability experience?

- Michael
 

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Where does the MAP's input show up in the power curve or drivability experience?
That depends on what control algorithm your ECU uses.
Mine uses speed-density (RPM Vs Air Volume) so the MAP is a very critical input.

If you common up each ITB using little rubber hoses and tee pieces what you are effectively doing is making a small manifold through which air can flow too and from ports thus creating a sort of average (though not entirely accurate) measurement of pressure.
Unfortunately, due to the nature of individual cylinders going about their usual business you also get a lot of pressure pulsation as well.
Hence devises like restrictors, capacitance chambers, etc to try and even things out and provide a stable input for the ECU.

The trick is to dampen the signal enough that fluctuations don't cause poor engine control, but not to the point that response time suffers.
 

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Discussion Starter #16
Greetings: making progress here. The electronics are all done, but I need to finish up the radio install before buttoning up the console. I fabricated a small box to hold the GoTech controller and the two new gauges. They are mounting to the console where the ash tray was.
 

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Discussion Starter #17
Running!!!

Greetings:

The Alfetta is running. Not much drama, really. One small fuel leak under pressure, adjustment needed on exhaust system being tapped by the rear-most driveshaft gibbo and an oil pressure sender swap. Well, the sender present a bit of drama. I was not impressed with the original oil pressure readings (##$%!!$$), and then I remembered that the installed sender came with the block, while the one I "knew" worked well with my gauge was still mounted on the original block on the shelf. All is well there now.

I was a bit amazed that the original load tables worked, but I guess I should not have been. (thanks junglejustice!) Having the wide-band sensor was certainly a comfort, as I could see quickly that nothing was amiss. The GoTech has a "trim" pot on the dash panel, and it supposedly changes the injector times +-10%. That can be seen in real time - actually is instantaneous, as it is turned up and down. The AEM reads in the mid 13's normally, and the pot will drive that up to 14 or down to the 12's.

I looked at the GoTech laptop software for the first time last night. One thing of note is that it is set to run a "mixed" TPS and MAP algorithm.

I have been reading more about set-ups in a great document called AEM EFI Basics. I can't seem to find where I got it from (obviously from the AEMpower.com website), but if anyone is interested, I'll get you the PDF.

I feel fairly comfortable running as it is for a bit while I break in the engine. My primary goal going forward is to insure I eliminate the annoying stumble and pogo action on neutral throttle.

Photos show the installed controllers and the associated wiring. Most of the time here was spent getting the radio hooked up. I used the original airbox, but cleaned it up and crinkle powder coated it, along with the valve cover.

- Michael
 

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I have a different brand EFI but the mixed tpi and map is for a smoother idle on engines with a performance cam. I have my tps set at 0s. My afrs are around 15 for normal driving. I have gone as high as 16.5 without issue. It richens up on load though.
Try working with the accelerator enrichment. That had a huge effect on low throttle driveability.
Also, if possible download and save your program often. I use the date and a 1-10 rating of driveability. That way if you bugger the setups you have something to go back to.
 

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Discussion Starter #20
I have a different brand EFI but the mixed tpi and map is for a smoother idle on engines with a performance cam. I have my tps set at 0s. My afrs are around 15 for normal driving. I have gone as high as 16.5 without issue. It richens up on load though.
Try working with the accelerator enrichment. That had a huge effect on low throttle driveability.
Also, if possible download and save your program often. I use the date and a 1-10 rating of driveability. That way if you bugger the setups you have something to go back to.
Thanks for the suggestions. Our household uses Audi Quattros as daily drivers; are they the source of your nickname?

I am a storage systems guy, so I fully embrace the concept of "backup often".

This AM, I set the GoTech up to generate 0 advance at low rpm, so I could calibrate the distributor at TDC while she's actually turning. That done, I set start advance (0-500) at 5*, with 11* at 500-1000. I was able to get a fairly stable idle at 700-800 rpm. I need to get back out on the road to continue, but that won't be today.

- Michael
 
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