coolrimsatleast

I've been contemplating switching to SFI since I'm just not getting the mileage I should be after my 3.4 swap. Can't find any vac leaks, etc etc.

Anyway, From what I've read after searching, is this pretty much what I'll have to do to convert it? I've got the cam and crank trigger stuff sitting around, and there's two 4th gen V6 camaros at the wreckingyard.

Obtain a 1227148 ECM
install the crank trigger and Cam Sensor
install the wiring harness going from the ECM to the injectors

I guess that would be the way to go since I have a MAF. Or would it be better for some reason to convert to MAP, since that's what the 4th-gen V6's use anyway (unless I'm mistaken), and grab an ECM from one of those?

If anyone has done this, or has any suggestions, let me know.

I'm goint to do some more searching on this tomorrow, it's too late and I"m tired at the moment.

noahTHEpurdy

iTrader: (1)

What kind of mileage are you getting with the 3.4?

Dale

iTrader: (12)

I installed 94SFI into a 93 s10. If you search YEARS N YEARS back, you will find a few post of me asking questions.

First off, there is much more to SFI then you point out.. or atleast for a 94 system. Maybe the FWD setup would be easier. The Turbo s10 guy will have to help you there.

For 94SFI, you have 1 cam sensor, and 2 crank sensors. You also have coil packs.. and I think there was 1 or 2 other added sensors. I had to gut 90% of the s10 harness, and go full SFI harness. There was only 2-3 places I attached to the s10 harness. I had to make about 4-5 fuse spots for power(plus the main power point which is one I attached to the s10). Then I later had to extend EVERY wire that went to the ecm to install it where I wanted. This is ALOT of work, took me about 3 months for a full motor/wireharness swap. Your gain wont be much. Above 3000rpm, I belive both ecms run in full batch? You only have sfi below 3000 which I know is where you are most of the time. But I dont think your gains will be worth your cost/effort. I even wonder if TBI to SFI was worth it. But it IS years ahead of a carb, but then thats even more work.


I am going to bet that your still running the stock prom. I would try and have someone burn a chip, or learn to. From my readings, these chips are wack from the factory, and only get worse every mod you do. I still need to learn to do this. Also, the 94SFI ecm has zilch support(or 3 years ago), where your stock ecm has tons of support to make it do what you want.

Project: 85 2.8 bird

having a 94 comero, and post whoring over at cv6, I hav jsut one thing to say about it:

true dat.

daves12secV6

iTrader: (3)

forget tunning ur stock ecm the 302 has 0 support as well, its a watse of time. atleast if u were running the 7730/sd ecm u would have some options.
this is why i never got into tunning the ecm with my turbo setup i also have a 302/maf.

i would highly consider doing a 7730 swap,or going to megasquirt.
u can order a fully assembled megasuirt,with harness and cables for 311$'s delivered to ur door.

i just got mine and about to install it,in ur case with minimal mods instalation would be quite easy as u would prolly only need to runn in piggy back mode controling fuel only, unless u opted to control spark as well, which is an added few wires to hook up.

u can run full standalone controlling fuel/spark and still leave the stock ecm in the car for controling the fans/tcc lockup

coolrimsatleast

22-23. That's down from my avg of 28.5 all last summer (33.5 on the freeway) About 80 miles less per tank now. I also have an on/off vibration at idle, almost like it's in gear even though I'm in N or Park, but I can't find any vac leaks. No codes.

I might change out the ignition module this weekend, and maybe the plugs too. I'm also getting a new air temp sensor and some MAF cleaner I heard of.

Anyway

If it's a major job to change to SFI, then maybe I won't bother. I'll do some searching and look into changing to MAP and adding the 7730 ECM (been through trying to find laptop tuning stuff for the 302) and read some more into megasquirt. I've heard good stuff about that.

I still need to find out if something is wrong first.
Mystery vac leak? (tested everything with a gauge, replaced most of the hoses, and sprayed carb cleaner everywhere)
correct o2? (had to switch to a heated denso, but some say o2,s are made for specific ECMs)
ignition probs? (doesn't seem to be missing, sort of)

Only major changes other than the 3.4 block and 17lb injectors was addition of the pacesetter headers, and 1.52 roller tip rockers.

firstfirebird

iTrader: (3)

That could be a major factor sinc o2 sensors go in both directions
ie: high voltage= rich or high voltage= lean.

A programmable o2 sensor is what I am using (Innovative LC-1) and when I first hooked it up, I was unnaware of the two types of signals with sensors and things were all screwy until I found this info (LC-1 uses a Bosch o2) and re-programmed it.

daves12secV6

iTrader: (3)

no the denso o2 u are using is fine. some imports use a different signal from the o2. as long as then one u have works on a 0-1v signal it will work

noahTHEpurdy

iTrader: (1)

I wouldn't be complaining at all with that. I get about 20 mpg on the 3.1 I have. I think you're doing good for yourself.

coolrimsatleast

Well, I managed to bring it up a little. I went 352.8 miles on this last tank, which came out to 25.4mpg after putting in 13.9 gallons. I still have some little things to mess with, plugs, timing, t-stat (switched to a 180 lately) and a tiny exhaust leak where the pipe hooks up to the cat.

I need to check out the bushing and such in the front. It doesn't seem to handle like it used to.

I'd like to get back to at least 27-28 before actually messing with ECM changes, megasquirt and whatnot.