I'm beginning my EFI project for the turbo car and wanted to get the part numbers and the place to buy the various things i need to upgrade the injector drivers like you have.

I'm using a 727 or a 749. i have the 727 so i may as well....

I want/need to run 42lb or 50lb high imp injectors and am not quite clear on what you are running and how that worked out.

Does it idle much better with the injector driver upgrade?

I have a buddy that has been in the electronics business for years and both he and I are positive he could do anything you tell him regarding putting new things on the board.

Thanks,
Jason

 

If your going to use HIgh Z (Saturated) injectors then you do not need to modify the drivers.

The mod is only needed when you use a 749 (the only ECM that has both driver circuits populated) to run more than 4 low Z (Peak and Hold) injectors.

I am using SVO brown tops (low Z) so the mods are needed. Here is a webpage that goes over the mod.

http://mywebpages.comcast.net/p-928/749mods.html

cheers, Bob

 

I hope this might also help:

https://www.thirdgen.org/techbb2/sho...hreadid=236732

 

With injectors this high and no modifications, i can't just set the size of the injector and go though right?

I have to mess with several factors to get the computer to be able to run with these?

 

Thats pretty much it.. Tho I don't know how well the PW's at idle will be. But it has been done.. Just not by me. BW

 

Hopefully, I’ll finally know later today if I can get a ‘165 to idle with significantly bigger high Z injectors (I’ve got some 36’s, 47’s and 77’s laying around, I’m probably going to try the 47’s)… assuming that I ever get this TPI back together without any leaks. I started with a leaking water pump, and next thing I know I’ve got the intake and fuel system apart, I’m making blockoffs for the EGR, 9th injector, the fuel rail fitting for the ninth injector, I made a new adjustable FPR, cut .100” off the top of the fuel rail hold downs (since I didn’t like all the discussion of what to do with the fuel rail clips… when running bosch/ford injectors), cleaned up the outside of the runners (they were just looking nasty), I intend to try RTV or some kind of non hardening sealant in the place of the TPI gaskets, since I’m tired of ripping those things apart every time I’m interested in trying something… lots of little, dumb stuff that took too long

FWIW, on a similar but different note, when we swapped 77’s in the place of the 36’s on my brother’s car we just changed the injector constant and it started right up (old Haltech that can drive 4 low Z or up to 12 high Z injectors).

I’ll see what happens… if that works the next step will be something a little different (at least I haven't seen anyone else run this wierd combination of parts).

hum... has anyone ran a GM ECM in single fire mode? How does it run? I figure that I'll try that if it won't idle well "the normal way"

 

sounds good mark. Let us all know as its been an arguement on here for some time.

 

Well, so far it's nowhere near a success. It won't idle and won't keep running in any kind of useable range, and what seems to keep it running isn't really making too much sense to me right now (and I can't really try cranking it that much in the middle of the night).

I'll tell you right off, it is not nearly as simple as buring a prom that worked fine with the previous injector constant with a new one.

If anyone has some suggestions how to get it at least running well enough to tune I'd appreciate them. I posted more details in diy prom:
https://www.thirdgen.org/techbb2/sho...hreadid=245778

I’d really hate to have to take apart the runners and install reasonable injectors at this point, for that matter, if I can't get it to idle with these, then there isn't any point in even trying when i bolt on the turbo setup and need the really big injectors.