Project EFI TT 300 is underway


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Well, I don't have much to show for it yet, but, here's the PCM I'm going to be using:

It's a GM unit, I pulled that one from a 2.8 V6 powered 87 Pontiac 6000.
I'm going to be burning my own EPROM's for it, and, all kinds of other fun stuff... I will be keeping you guys updated on the slow progress.
I was thinkin of using GM equipment on my custom EFI 300 project on the drawing board. The GM sensors and computer controls are very easy to calibrate and work with. If i used a stock 300, EFI wiring harness, with GM sensors on it, then i wouldnt have to biuld my own harness. Even though biulding my own could be fun.

Are there any other ideas as to what other computers would be good for a moderately high performance EFI system? 4.3 V6?, any of the new OBD II 6 cyl. computers?

How would you go about programming a computer for an inline with a different firing order than a V6? And any others differences the computer needs to take into consideration for injection control?

I would like to use Junkyard parts as they are cheaper. I am very interested in a custome EFI for my 300 and ive got some of it figured out.

The turbo will be the brain scratching learnin fast!

Ok ill stop asking questions...but i got many to ill ask a little at a time...
The Delco P4/Memcal unit is usally bank fire, but the control is at the chip, not the whole unit . In Australia, the unit is used like a 9 inch diff swap...its fairly cheap, bullet proof, and can fit anything. Chevy Off-Road and Marine in Oz have a twin table Delco P4 which runs two different modes...gasoline or LP gas, or gasoline low-performance (switched on when your kids drive the car, sort of like the Quad Cam Corvette system of locking the hp out) and optimised high performance. Another one has a Nitrous/gasoline and straight gasoline table.

GM modified stuff isn't always long as your moving Ford!
Am collecting pieces to work up an efi system using pre '93 V-6 3.8 T'bird manual trans ecu, pre'93 = pre ignition control. The Mustang bunch are making +/- 400 HP on a simply modified system. The engines are blown but the only blower specific mod is a boost modulated fuel pressure regulator.
Mods needed are few, bigger throttle body, bigger MAF sensor, larger injectors and higher capacity fuel pump w/ adjustable press. reg. Throttle body can be from a bigger Ford, am using a dual bore from a 2001 4.6 Cobra.
All other pieces are stock Ford; sensors, wiring harness, etc. Some are adding a chip from "" others are not. Fine tuning is done with fuel pressure regulator.

Did not understand comment about V-6 firing order. All even fire sixes have the same firing spacing. Firing order of spark plugs or injectors, it is simply a matter of getting the right wire on the right item.
From what I have heard and read, the ECM doesn't care so to speak(unless it's TPI I assume)

If you're gonna use TBI go with ECM #1227747 (future reference)

TPI or anything of tha nature I'm not sure of as I don't use it but have read about it. Go to


For GM ECM stuff, check out

For a TBI setup, you want a 7747, if you're doing a 6 cyl, it's best to start with a comp from a 6(TBI 4.3, truck issue) For a port injected setup with a distributor, the 7730(2.8L and 3.1L A bodies, Celebrity, Pontiac 6000 ETC) is the ECM of choice and, it will run the $58 code of the 7749(essentaily the same computer, but, setup to handle boost.)

As for Ford stuff, I haven't started playing with that stuff yet....

Forget the Ford stuff, the GM-ECM's are fully hacked.

The 7730's primary use was the 5.0/5.7L Tuned Port Injection from 90-92.

Also the 2.8/3.1L MPFI V6 in the same years.

It can run a variety of differant Masks, but the $8D is the most well documented and most capable for NA applications. It can operate either a 6 or 8 cylidner engine.

the $58 Mask is from the Syclone/Typhoon/Turbo Sunbird. It is very similar to the $8D Except for the added features of 2/3bar MAP, electronic wastegate control, and some other turbo specific features.

the 7749 Is the GM computer which came in this applications, and is capable of running up to 8 High Impedance injectors or 4 low impedance peak and hold injectors.

However, this ECM is hard to find. It is structurally very similar to the 7730 and the $58 Mask will run without problem on the 7730 ECM.

You can dick around w/ fuel pressure ect on a differant ECM, but if you want to really do it right - You need to have explicit control over the fuel and spark tables.

The GM-ECM's have been sufficiently hacked to allow just that.
I was looking at the GM schematics and was thinking that I might pull the system from a chevy PU and mount it on my 300 I havent fully explored it but the TFI and the GM electronic system used with the ECMs look compatable. You can buy an adapter plate to mount GM TBIs on regular manifolds but I've already got the aluminum plate, I just need to cut and tap it, 90 bucks my butt I got the plate for the weight of the aluminum, I think it was three dollars. And if the TFI isn't compatable I'll just have to replace the distributor. The GMs are a dime a dozen in the junk yards, the Ford CFIs are harder to find and they charge too much.
All you need is a magnetic pickup driving a GM module.

I don't know if the TFI works, but if it doesnt juse use a Duraspark dist w/ the mech Advanced locked down.
HERE IS WHAT YOU DO! First you go get a complete tbi off a late 80's 4.3 astro van.including the dist,[you sell the dist. later], including the wiring harness and computer,[make sure its the 1227747 ecm]. get the map sensers and all. They will be attached too the manifold. Get the oil pressure sender and the temp senser. if there is anything left on the top of the intake you didn't get it all. Around here this costs a hundred dollars. The ecm will already have a 6 cyl. chip.
The next step is go to ... ection.htm and click on gm manuals. It will take you to the 1227747 ecm prints. My harness had 2 wires different color but still easy to figure out. You will have to build your harness from these prints.
You can use the ford dist. just lock the advance plate down.Connect the ford dist. pickup to the chevy 4.3 dist. module with 2 wires,it can be attached outside the dist. on a well grounded heat sink. Connect all wires inc.o2 senser and hope you can get the chip programmed. I DON'T KNOW? I've only got this far!
Hey Ian... :D

Yes I'm lurking....

my 68 F-100 stepside's 240 looking for more power...

malibu's just about ready. maybe friday. needs aligned.

Hows the TT project going? I'm considering 2,SAAB 900 T3's but I may just use a single modifed GN turbo on my 240.

The 730 ECM will work with boost, just need to wire it like a Typhoon/Syclone and use Ty/Sy ($58 ) code.

My malibu runs either a 730 or 749 ECM with $58 code. A buddy and several others are working on a fully commented hack which will make, making code changes much easier.

A Ford distributor pick up will trigger a late GM ignition coil. The biggest problem is the Ford IAC is 2 wires, a GM is 4. Considering an adapter plate to mount a late LS1 style TB to a late 300 EFI intake.

cheers, Bob