Another newbie

Discussion in 'Injection Tech' started by Howlingmoki, Oct 11, 2017.


  1. Howlingmoki

    Howlingmoki Farmall Cub

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    Hi everyone!

    Like a lot of people, I wound up here because this is where the TBI knowledge is concentrated. The closest I've been to owning an Binder of any kind was a huge '54 R210 (with the RD450 straight-six) a buddy rescued from a farm and revived -- we towed it home with an F350 and a pipe-and-chain setup while I steered the IH for six miles. Good times, good times.

    I've been cooking up a TBI conversion for my '73 Mercedes 280C, 2.8L M110 DOHC straight-six, that was originally fueled with a bad copy of a Quadrajet. I replaced the Solex Q-jet copy with a Quadrajet to get it moving down the road for shakedown and testing purposes, to see how the rest of the car is. I'm doing fuel only because the car is slated for an M103 swap probably next summer or fall, and I'm wanting to do as little as possible to get it decently driveable until then. Ignition on it is a points-triggered electronic (transistorized) system that *appears* to have a clean enough output to not fry the ECM without a filter. I didn't see any high-voltage spikes on the scope I'd borrowed, at least...

    I know I need to edit and burn a chip, both to turn off spark/knock control and EGR as well as fueling maps. I've got an older Macbook booting Win7 and running TunerPro 4.14 because the 5.x release of TunerPro/Pro RT were having fits about a runtime and I gave up trying to fix it for now. Also have a TL866 MiniPro USB EPROM burner, some blank 2732A EPROMS, and a vague but growing idea of what I need to do.

    TBI donor was an '88 S-15 4.3, 1778062 ECU with the AMRW bin. I've got a set of 2.8L injectors in it now but have the original 4.3L units in a coffee can of clean diesel for storage. I cleaned, re-routed and re-wrapped the harness for my needs while trimming out the connectors for the ESC/Knock/EGR systems, and I don't have the O2 sensor or VSS connected yet. It started and ran poorly and very rich with the stock chip and 4.3L injectors, ran better but still terrible and rich with the 2.8L injectors. Interestingly, when I burned copies of the ANFJ and ACJH bins and popped them in it ran worse and even more rich -- like "I see fuel puddling on the throttle plate" rich. Wondering if there might be issues with the bins I downloaded from gearhead-efi.com but I don't know how to verify that they're any good. Would it be better to hold out for a 7747 ECM instead of the 8062 I've got?

    Back to poking at TunerPro for a while. It's great bedtime work, puts me right to sleep. LOL
     
  2. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    Welcome to the fun.
    You can use the 8062. I prefer the 7747 since it was used for all engines so it seems to adapt well to any engine.
    I have found many 4.3 bins used async fueling mode due to the design of the engine and manifold. GM even used 2 different size injectors on them.
    To get the basics down you need to take a look at the FAQs under the "start here" thread.
    Then scroll down towards the bottom for the basic data logging and tuning section.
    Being fuel only makes it pretty simple. Just log data, adjust the fuel table and you should be done.
    You have a 2.8 so the basics are the same.
    An inline 6 fueling is much different then a V6 so it will need adjusting.
    Then just turn off the error for anything not used.
     
  3. Howlingmoki

    Howlingmoki Farmall Cub

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    I've been working through the FAQ since before my post, good stuff in there. It's just slow going on my end because I'm having to work on this around both my job and She Who Must Be Obeyed, plus I'm working in the driveway. After some tinkering yesterday, finally getting the SES light connected and reading up on SES codes I'm thinking the signal I took from the ignition wasn't clean enough and that I fried teh ECM. It doesn't start at all, and I'm getting a constant fast-blink with the key on. Didn't have much time after that to poke at it any more, won't have time until tomorrow afternoon.

    The biggest issue is I'm relatively stuck with the distributor that's in it. I could ditch the points and transistorized box for Pertronix, but I'm not sure that would take care of the issue. Later years of this motor had electronic ignition, but the only distributors I'm seeing right now cost more than I paid for the whole car so I'd rather not go that way for "temporary". If I do wind up needing a filter, any opinions on this circuit?
    [​IMG]
     
  4. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    I have preached this from day one, if you set up the system as it was designed, it works great.
    I personally think you will spend more time trying to work around the timing control then if you just converted the distr as shown in the FAQs and ran the system as designed.
    The only difficult part of the conversion is turning the lobes off the advance shaft.
    If you really want to run fuel only then the easiest is to run an MSD box and use the tach signal out to trigger the ECM.
    You can use a filter but I can't comment on any one specific without building and testing it.
    If you need to swap ECMs then just go with the 1227747. Look at car-parts.com Look up a 1990 1500 ECM and go to the page # with the * next to it. That will be the lowest price.
    Here's some more tach filters you can try. I have gathered these over the last 20yrs. If I was going to do it, I would use one that uses the 555 timer chip.
    I also have additional circuits to connect the GM ignition module and trigger it with a points circuit.

    555VDO filter.jpg

    Fuel only FILTER.GIF

    tachcircuit.gif

    Tachometer.gif
     
  5. Howlingmoki

    Howlingmoki Farmall Cub

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    Understand and appreciate that it'd be best to stick with the system as designed, I'm just very hesitant tomodify the existing distributor because of cost/scarcity issues. I've seen a diagram for triggering a 4-pin HEI module with points and a pull-up resistor, I've also seen a couple diagrams for triggering a Ford TFI module with points and I actually have the TFI stuff on-hand leftover from a project 15 years ago. I also see Chineseium 230/250/292 big-cap HEI distributors on Fleabay for ~$60 shipped .. maybe I should look into modifying one of those to fit the Benz engine. I've got a buddy with a lathe and a Bridgeport...

    I spent some time earlier this morning looking at pinouts for the 8062 and 7447 ECMs and they look nearly identical except for an A/C clutch wire at A2 on the 8062 that the 7447 doesn't have, and since I'm not running A/C anyway....
     
  6. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    Both ECMs are C3 and are directly swappable. The wiring is the same. You may just be looking at a model specific diagram.
    The AC is a sense wire and not an AC clutch control. It simply senses the 12v on the clutch wire when the AC clutch is engaged.
    But with an IAC there really isn't any need for AC sense and the idle adder is normally set to 0 anyways.
    I use it for many other functions but not for AC idle speed adjust.
    It's all covered in the wiring FAQ.
     

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