BMmonteSS

I've found some ferd turbo coup injectors. They say they are 36 pph. Is this correct and will these things fit in the standard injector bungs. I'm currently piecing together a MPI setup and these looked like a good deal. Also can I get these things turned down enough to idle with a ~300 hp setup. I'm going to be upgradding to a 400-500 HP setup in the future. I'm currently running a 454 TBI, and I'm planning on swapping to a 749 to learn the ropes with the TBI unit then swaping to my MPI setup when I finish fabing it up.

Grumpy

Da GN guys been using them for decades.
If they can gettem to work on a lil 231 I don't see them being a problem on one of them big v8s.

BMmonteSS

Thanx Grumpy, I really need to find time to get over to the GN boards and sniff around! Ya'll come back now Ya,hear!

KurtAKX

Well it makes sense that if they will idle with the 2.3 in a no boost condition @ 575cc displacement per cylinder, and they can work fine in a GN with a 633cc cylinder, than the 975cc cylinders of a 454 will be easy for the turbocoupes injectors to deal with at idle, doesn't it?

BMmonteSS

Makes sense now that I think about it. Also this is going on a 350. Now that I reread my post it's a little vague as to what motor the 454 throttle body is on. Guess it's that WV grammar

BJM

GN guys use 60# stuff quite commonly now. I myself just put some Ford 36# injectors in my GN. I fiddled with the injector constant and needed a little more tip-in fuel from my stock sized 30# ones. Otherwise they ran fine right away.

Grumpy

Those are what's in mine currently. As well as a 749, meaning batch fire mode.

zapo

The turbo ford 2.3L brown injector is a low impedence injector. It measures 2.3 ohm's vs the ~14 ohms of the stock GM injector. IT will cook a stock ECM that is not setup for "Peak & Hold" type injectors.

BMmonteSS

I didn't know they were peak and holds, but I was planning on using a 749 any way.

BMmonteSS

Ouch! man where do you guys get your 749' ecm's at. Their expensive on ebay. I only found 1 and it's up to 70 dollars with 5 days left. I did find like 4 730's with buy nows for 25$. Are the 35# injectors really low impedence?

Dave_Jones

Best way to find a 749 cheap is to hit your local salvage yard, and look for '87-88 FWD cars with the 2.3L Quad 4 engine.

I don't know exactly which years they were used on turbo coupes, but the Bosch "blue top" 36#'s are high-Z, and would work fine with the stock GM injector drivers.

BMmonteSS

The turbo coup injecotors are brown tops, with a bright aluminum body, so they probably are the low-Z. Thats ok I'm wanting to run my TBI setup for a while on the 749 anyway.

Is the 749 used on all the quad 4's or just on the turbo versions.

JT

iTrader: (1)

Just to help out by also confirming.

The brown tops (35#/36#s) were used in all 87-88 Turbo Coupes from the factory for certain. i believe they actually started out in late 85 Turbo Coupes. Before that, they were green tops that were rated at 30# if i recall. The brown tops on the Turbo Coupes are low impedance and known as "peak and hold" type.

BMmonteSS

Thanx for the injector info!

As far as I can tell from the online parts stores the non turbo'd sunbirds got a 748 and were a single TBI. I wonder whats different between the 748 and the 749 being that they are only one part number apart?

Dave_Jones

All. (Actually, I don't think GM ever sold a turbo Quad 4 on a street app. Turbo Sunbird -- also had the '749 -- wasn't a Quad 4). Sometime around '88/89 the Quad 4s switched from the 1227749 ECM to the 1228707.

'748 has card edge connectors, I don't think it's much like a '749 at all.

BMmonteSS

Thanx, time to hit the yards! I just got my LT-1 fuel rails and 4 of my turbo coupe injectors.

KurtAKX

Lots is different actually, besides just the edge card connector. The 748 is a cheap "cost save" ECM with a reduced feature count. It was used only in low performance four cylinder applications, with TBI and DIS. It doesn't use a memcal at all, but rather a simple outdated 128k PROM stuck directly into the board that is virtually impossible to find a replacement for. There is no starting BCC for you to use this cheapie ECM on anything other than a TBI 4 with DIS and NA. I think it can only drive one bank or one injector anyway.

This ECM is what was in my old Chevy Celebrity 4 cyl wagon, and I have a spare unit and the definition file for Tunercat.

BMmonteSS

Good info thanks again, sounds like it's alot like my monte's stock ecm, the board actually looks like there is less stuff on it, compared to the 747 I have in it now.