Possible GM alternative

**POS carb** · 08-26-2002, 10:36 AM

Hey check this out, it's a 400 CFM kit for GM trucks, this could be a cheap alternative to those who want the drivability of EFI and a bit better MPG without the cost and hassle of MPFI, all you'd really need to upgrade is your fuel pump, not sure if this system requires a return line but that isn't too hard to do and if funstick can decode the ECU's in his project to work with our harness we could have cheap and easy EFI for those who aren't ready to throw a grand at their cars.

$300 and that's EFI and 400 CFM, price competitive with the weber if not for the ECU

***A20A1*** · 08-26-2002, 05:07 PM

Lalalalalaaaa! Whats the throttle sizes, and is it progressive or syncronous?

I wonder though doesn't the holley conversions for their carbs come with their own computer to controll the TBI, I mean it seems like all the sensors are mounted on the carb... maybe only the ignition would be needed afterwards.

**Sean** · 08-26-2002, 07:56 PM

already ahead of you. got a prefect ecm for this kind fo applcation
the gm 1227747 already hacked and ready to go. need some help eric???

**POS carb** · 08-27-2002, 12:56 AM

OMG u are the man... I will be in contact with you about this, right now I'm beginning a cross country move so I won't be messing with the car or the internet much but this is definately something I want to check out.
kick ass, it's like a 400 cfm carb that idles perfect! :super:

**Site** · 08-27-2002, 04:25 AM

Please don't keep this between you two, Eric and Funstick, as you progress. It seems like Funstick always has a handful of things he's working on that never get good exposure on the board.

**Sean** · 08-27-2002, 08:23 AM

oooohh ive got so muh stuff you wouldnt believe it.not all honda related but fun never the less.

***Vanilla Sky*** · 08-27-2002, 08:47 AM

funstick, i would love to know all the stuff you have done and are working on... when you get some spare time, write it up in a thread

Derick

**shepherd79** · 08-27-2002, 11:52 AM

how much stuff would you have to do to make this thing work?

**Sean** · 08-27-2002, 01:18 PM

oh just add about 4o circuts to the car for the ecm to work. pretty simple

knock sensor/map sensor/igntion module/injetcor wiring/temp sensor/tps sensor

other than that not much really the 1227747 is a pretty striaght forward ecm. its so divided form the electrical system in most tbi fullsize picups that its almost a stand alone. ooh and a vss of some sort.

**shepherd79** · 08-27-2002, 03:39 PM

oh well it is to complicated for me.
my dad has 89 WV passat with monojetronic which looks like the one above, and i tell you that it is nothing but pain in the ass.
i think i will stick to weber upgrade. but i would love to see someone making this thing work.

**Sean** · 08-27-2002, 04:13 PM

all you need to do is goto the junkyard and find a 86-93 fullsize pickup form gm or chevy and make sure its TBI. next get behind the dash to get at the ecm. if its a 1227747 your in business. yank the engine harness do not cut connectors. grab all the engine sensors to. i mean everything. sorting it out is pretty simple. theres gonna be a power feed and a couple of a/c things but its really not very hard. should take you about 2 weeks to sort the harness down to the things you need. realy its very straight forward onc you get familiar with the schematic.

**Sean** · 08-27-2002, 04:19 PM

as for a TB unit get one from a 2.5 4cyl cavalier. its compatiable with a 1227747 may take some mode to mount it on the a20a intake but nothing a peice of plate aluminun and a drill cant make.
no the cavailer doe not use the correct ecm for this swap. i will post a base line modified BIN file for use for this project. other things youll need are a eprom programmer and and alot of extar chips.

the chevy cavailier 2.5 cylinder fuel pump should fit the accord hanger from what i remember it pretty close in size. adding a return line is pretty easy as well. your looking at alot of what i call prefab. building things before you plan to put them on. you can test all the sensors and wiring with a DVM long before you put them in. taking it a weekend at a time should help to. say put the return fuel line in on a weekend. its not that bad. just think there is no ready made answer for you yet.

***A20A1*** · 08-27-2002, 04:49 PM

hmm I'm sure I we could mate a 2bbl carb spacer for holley and eddelbrocks onto the a20 manifold, but we also have to use one of the plates used for a weber conversion... since the keihin has offet bolts and the weber has equaly spaced bolt pattern.
Then just bore the plates as needed using the gasket of the TB. The only problem is the hood clearance... if you don't mind a cowl sitting on top of the hood then go for it.

I've tried to mate 2bbl carb spacers directly to the manifold but there is not enough material in some areas to drill a good hole.

**Sean** · 08-27-2002, 06:49 PM

just some random thoughts

***A20A1*** · 08-27-2002, 07:30 PM

well i didn't mean to sound like it was a bad idea.., i would do it if I new it would be easy tracking down the parts and hooking things up.

**Sean** · 08-27-2002, 08:15 PM

aside from mounting the TBI its cake also youll need to weld the advacne weight on yr distributor to remove the mechanical advance and remove the vacum advacne line. wiring up the gm igntion module is easy.

***A20A1*** · 08-27-2002, 09:02 PM

how come you need mechanical advance?

**Sean** · 08-27-2002, 11:13 PM

all the three 3g accord efi and carb have mechanical advance. you need to defeat it for the gm ecm to contorl timing.

***A20A1*** · 08-28-2002, 01:04 AM

oh so basically you just leave the distributor locked in one timing position and the ecu does the rest...

I know the stators move by the vacuum advance linkage...
but what part is the advance weight?

**Sean** · 08-28-2002, 11:01 AM

the advance wieght is located under a plate under the rotor bottun. should be simply to just tack weld the weight in place that will stop any advance.

**POS carb** · 08-28-2002, 11:26 AM

damn so you'd recommend I get a Cavalier TBI instead? It's cool cuz it's way more cost-effective but 80's GM shit scares me

Oh and emmissions compliance won't be a factor :super:

**Sean** · 08-28-2002, 11:34 AM

yeah the the later 89 90 cavalier tbi would be a good start. you can put bigger injectors and what not it. theres alot you can do if you want to. theres some other tbi's that would work but sizing might be iffy. the 1980's 2.8 v6 s-10 tbi's should work. a little bigger than the cavalier for sure. also for any of this to work yr gonna need to to do some pretty serious eprom work but not so much as to make itimposiable. where you moving to eric ??

**Sean** · 08-28-2002, 11:38 AM

do have have acess or know someone with a eprom programmer ???

**POS carb** · 08-28-2002, 05:20 PM

I'm moving to Miami, I'll ask Juan (oldschoolswap) if he knows anyone out there.
I just thought a cavalier TBI would be restrictive but I didn't know it was 2.5L.
So how will the ignition work? I'll need to hybridize the Accord distributor with the GM advance mechanism?

**Sean** · 08-28-2002, 05:39 PM

no youll need to freeze the advance in the accord distributor. then use the accord ignion pickup to fire the gm moduel. its only 2 wires. as for wiring harness like i said an 86-94 gm chevy truck should have a 1227747 ecm get the harness and ecm. after that get a good schemtatic for the said chevy truck with tbi. remeber that only fullsized chevy trucks use the 1227747