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| ECM upgrade (1227730) for stock 2.8 (Page 2/107) |
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Brian Lamberts
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JAN 10, 11:10 AM
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Great writeup, going into my junkyard tool kit, so I can look for parts.
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BobadooFunk
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JAN 10, 12:13 PM
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86_IRM_TURBO
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JAN 10, 01:19 PM
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It certainly sounds like it has Excellent potential for my 2.8 Turbo car.
I'm waiting for the details to spill out as well. I've already asked my
yard supplier to look for the ECM.
Thanks! Nice work!!!
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Darth Fiero
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JAN 10, 02:03 PM
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Wow, so many questions...lets see if I can answer them all...
Tuning - Believe it or not there were quite a few changes required to the 3.1 programming to get it to work with the Fiero 2.8. It seems as though the stock Fiero 2.8 wanted a little more fuel and a little more timing than what was programmed for the 3.1 F-body engine. Although, some of that might be a result of the headers used on this engine as well as the bored out throttle body.
EGR Vacuum Connections - Vacuum caps were used to block off un-needed vac ports. I also installed late model GM electronic cruise control on this engine which allowed the removal of the vac reservoir and hard lines. The EVAP system did require the addition of a computer-controlled EVAP solenoid and some rerouting of vacuum lines for it.
ECM Wiring Changes - The 7730 ECM uses the same type of connectors as the stock Fiero 2.8 ECM. The only difference is the 7730 ECM uses a 3rd connector (yellow) and requires 2 additional grounds and some additional wiring circuits for the knock sensor, fan relay control, EGR, EVAP solenoid, and VSS input. All told, I only had to run 6 additional wires out to the engine from the computer to cover for these circuits. Everything else was able to be hooked up using existing circuits in the stock 2.8 harness. The 7730 ECM also mounts inside the Fiero using a stock, early 4cyl ECM mounting tray.
Multec Injectors - Multec injectors WILL work in a Fiero 2.8, even with the stock computer. There are different types of multec injectors tho. There are peak-and-hold type, which were only used in the Quad 4 as far as I know. There were high-imp type 12ohm units used in later model engines. And there were high-imp type 16ohm units used in late 80's, early 90's GM engines. The latter are a direct-replacement for stock Fiero injectors. In fact, I have seen the multec units in 88 Fiero 2.8's so that should be proof enough they do work. Of course the only thing one needs to watch out for is injector size. I believe the stock Fiero 2.8 injectors flow about 15 lb/hr. I think the multec's used in 3.1 V6's flow about 16 or 17lb/hr. Of course if you use a larger injector in your stock 2.8, you will need the chip reprogrammed to compensate.
EGR Plates - I have a design sitting on paper for the adapter. The one that was made for this project was made out of 1/2" thick aluminum. The most difficult part of the design is the passage that has to be bored into the surface that the DIG EGR mounts to in order to connect the 3-ports on the DIG EGR with the passage that leads to the EGR tube that feeds the intake. Therefore, some sort of mill would need to be used to make this plate. I would be willing to share my designs with anyone wishing to have a EGR plate made for their needs. PM me if interested.
EGR Usage - Of course, if you don't have emissions testing in your area, you don't need to hook up the EGR. It can be disabled in the chip programming.
Turbo Applications - While this computer could work in a turbo application, I think you would be better off using a 1227749 ECM running the $58 code mask (GMC Syclone/Typhoon 4.3 Turbo) modified to work in a Fiero 2.8 distributor application. If your engine has provisions for DIS ignition, I would suggest installing DIS and then using the 7730/7727 ECM running $8F code (Turbo Grand Prix 3.1)
-ryan
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FieroVin
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JAN 10, 06:33 PM
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Sounds interesting. I picked up a 3.4 for my 87 GT from a 94 camaro and it has the DIS and egr components already. Hmmm...
TTT
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Fierobsessed
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JAN 10, 07:32 PM
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I think you should make a kit.
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dratts
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JAN 10, 08:07 PM
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I think that is the same unit that Ryan Hess programed for my N*. It must be a good all around unit.
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Knight
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JAN 11, 02:32 AM
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What engines does the 7730 run? If I install it to run my 2.8 stock engine. Can I get it reprogrammed to run a 3.4L with a distributor or a DIS (forced induction later)? How about a 3400 with forced induction later? How about a 3800SC Series II or III? Not sure which upgrade to do. I have two Fieros. An 86 SE that has some ignition issue, but runs (trouble shooting in progress. Hope to God the ECM is not the issue.) I have an 88 awaiting my choice of engine replacements as I spun a bearing racing on a course with a lot of turns; some short and some long sweepers. Both are currently 125c automatics. Will upgrade to one of the current electronically controlled autos at time of engine upgrade for both. [This message has been edited by Knight (edited 01-11-2007).]
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Darth Fiero
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JAN 11, 02:50 AM
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The 7730 was used by the factory on the following engines...
-2.0L 4cyl TBI DIS
-2.8 MFI V6 DIS
-3.1 MFI V6 DIS
-3.1 MFI V6 distributor
-5.0 TPI V8
-5.7 TPI V8
Those are the only ones I can think of right now. I do know for sure this ECM will not directly work with a 3800 or 3800 SC engine or any other Buick V6. The way the ignition timing and crank sensor signals are set up in the Buick engines are buick-specific and won't work with the "Chevy" 7730 ECM.
The 7730 ECM is virtually identical to the 1227727 ECM (which was used in the W-body cars) concerning board hardware; the only real difference between the two was the 7727 unit was designed as a weather-sealed unit so it could be placed in the engine compartment and the 7730 is not weather-sealed so it must be placed in a dry location such as inside the car.
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Knight
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JAN 11, 03:00 AM
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That 2.0L. Is that the one in the late '80s Sunfire and Cavalier?
How different are the 3.1 and Carmaro 3.4 compared to the 3100 and 3400. Were the 7730/7727 used on the aluminum headed 3.1?
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