I bought a set of 28lb/hr SVO injectors from a guy on this board. I installed them tonight and reprogrammed my PCM for 29.4lb/hr injectors (28lb/hr @ 39.1PSI == 29.4lb/hr@43.5PSI). Prior to running these, I was running the stock 24lb/hr LT1 injectors.

When I fired the car up, it ran so lean that the headers started to glow before it went into closed loop. When it went into closed loop, the long term fuel trim percentages went to +25%

I then loaded my old PCM program back in, calling for 24.9lb/hr injectors. I took a drive and the long term fuel percentages were still in the +10 to +15% range throughout the RPM range.

So my question is this... What could cause this? Were the injectors not really 28lb/hr SVOs? Could he have given me 19 or 22lb/hr injectors? Is there any other possibility?

 

There are no 28 lb/hr SVOs. The popular 28 lb/hr injectors are LS1 injectors which run at a pressure of 58 PSI. At our pressure of 43.5, they will equal, if not a little less, the flow of stock injectors. If you can send me a picture, I'll be able to tell you exactly what you have.

 

here's a pic.

Actually, LS1 injectors come out to around 22lb/hr, which explains why it's still way lean with the stock setting.

I sure hope the few minutes of running like this didn't hurt anything. The headers got so hot that my STB was too hot to even lean on. I'm still planning on tearing this guy a new one...

 

Those are 24# SVOs from what I see. If you can give me a number off them, I can confirm that 100%.
The 28.8 injectors from 97, 98, 01, 02 and 03 LS1 cars come out to exactly 24.94 lb/hr at 43.5 PSI.
The 99 and 00 26.4 lb/hr injectors come out to 22.86 lb/hr, but I was talking about the 28s.

PS. I'm pretty sure you didn't hurt anything, but I wouldn't try it again. Also, sorry about the delay with the tune.. I've been going through a lot of stuff lately... I'll write you an email tomorrow.

 

The main number that I see is: 280 150 947

 

Yes, the 947s are definetely 24# SVOs...

 

i found it... after doing a search, I found:

280150947 Bosch 24lb/hr Fuel Injectors

Now I'd like nothing more than to go kick this guy's *** for damn near frying my engine.

Oh, and Ion, you're the man.