Hi,

Just curious if anyone has put together the injector driver boards to drive a 4 barrel tbi. I just bought a 900 cfm holley 4 barrel for a zz430, so you will see a lot more of me In the TBI section
Thanks
Dan

 

Its been done. There where also prefabbed boards available for a bit but where discontinued due to lack of demand. There are also schematics floating around for the injector driver boards. I havnt seen them since diy-efi went down but im sure someone still has them saved somewhere.

 

Yeah there was a guy on the diy-prom board making them a while back, I think his name was "yellow73bb" or something just like that. Might want to pm him or something, I'm sure he has the schematics you'd be looking for.

 

yellow73bb

Yes its one of his kits that I have but i didnt get i directly from him

 

AustinT,
Can you tell me where you bought this kit?
Ben.

 

I used the one I built for a while on my 900cfm Holly TB, and got so frustrated with the lack of reliable operation of the Holly that I finally took off the whole Holley setup and put on a 454 chevy TBI. Works very well now. It does'nt look quite as nice though -- the Holly looks cool.

The injector driver board worked well, but the Holley injectors kept failing, and sometimes the butterflys wouldn't close all the way. I took the TB apart 2-3 times trying to get the butterflys to close reliably, but the one I had was basically a poorly made piece of junk. The spring that closed the butterflys would pull the shaft to the side enough to cause the butterflys to bind.

Sold the TB and injector driver setup on ebay for quite a bit more than I paid for the 454 TB. Been happy ever since.

 

I am sorry to hear that...
Are the injectors really that bad? I've heard some guys with bad stories and others who have used a projection setup daily for 200,000 miles with no probs...

I was all fired up, ready to try one, now I
'm having second thoughts..
I suppose I can only hope that they have improved them since..
Thanks for your input,
Ben.

 

They changed in the last few years to a different injector (made by Delphi). Those are supposed to be quite reliable. The old dome topped injectors are the ones that I had trouble with. You can't get them anymore either (although there is a guy selling them on ebay). They got to where they would not fire reliably. The computer could compensate somewhat during closed loop, but at WOT, it'd always go lean because I'd be running on the equivalent of only 2 or 3 injectors instead of 4.

On the other hand, I have a projection-2 system on my boat (4.3L chevy engine) and it works very well. But, I only put a few hours a year on it, so I guess the injectors should last quite a while.

On my vette, I'm only running a 454 engine, not a particularly radical cam, and it won't run over about 5600 RPM, so the 750 CFM 454 TBI is more than adequate. In fact, I ran a 650 CFM Holly 2-barrel on it for a while (with the analog projection -- the one I later put on my boat) and it was happy as could be with it for a while, till I decided to go with a 1227747 setup and the Holley 4 barrel.

 

I have read that the bad injectors are the ones with the black domes.. Funny thing is that these are still pictured at the holley website when you see any pics of complete TBI units......
http://www.holley.com/HiOctn/ProdLin...A/534-173.html

but when you look at spare injectors they are a different (delphi???) type..
http://www.holley.com/HiOctn/ProdLin...IA/522-43.html



I guess the pics of complete units are out of date.

 

Hi, sorry i havent visited the boards for a while. The new TBi with the injectors from delphi, have the connectors at a 90 degree angle with respect to the injector. I bought a 900 cfm holley off ebay a few months ago but have not had the time to do the fuel injection swap.

It was a kit from yellow73bb but the guy who bought it had a change of plans.