ID850 injectors install.
 

Spent this afternoon putting in ID850's. Not a bad install. Ran into a little snag as the bolt that holds the fuel rail down on the front of the blower won't come out without running into the blower hat. Took a little air chisel and remove a tiny amount of aluminum so the bolt could come out. Then painted it with some black touch-up paint. Put the data in from Injector Dynamics, fired it up, and pig rich at idle. So much for being plug-and-play. Had to tune the injector offsets myself anyway. Now it's pretty close. I'll do more logging and tuning tomorrow.

First pic shows the bolt that wouldn't come out without some "help".

Second pic, see that I had to loosen the last bolt on the hat to allow that last injector to pop out. The fuel rail was hitting the end of that bolt where it stuck thru the blower casting.

good job...I had a trick for that front bolt which was exactly the same clearance issue as you show. Turn an open ended 10mm straight up and use a pair of vice grips on the wrench to turn. Once it breaks loose, you can almost get that bolt out with your fingers. Your clearancing was good as it will never present an issue again. My tuner had a slight problem tuning the idle as well because the ID850s flow so much fuel. At minimum pulse width the injectors still flow like a fire hose. Its fine however a hot start will ocassionally belch some black smoke. It's a small trade off to have safe fueling at higher rpms under boost.

That stinks about the injector data. That's supposed to be the great selling point on these injectors. Anyway, what offset did you use that worked? I'm getting ready to tune a friend's CTS-V with the same injectors and similar mods.

I'll get back to you after I'm done tuning. Suffice to say that at least 10% needed to be removed from the offset data provided.

Where should the A/F be at when at wot. 11- 11.7 ? Is it unsafe to be at 12ish

11.0-11.2 is good....we leaned it out on the dyno and lost hp 3 separate times...keep it in the richer zone and all will be happy and safe. Stock was right there in the same range and GM knows best!

Zo6bryan, how long does it take roughly to change out injectors?.

Depends on your mechanical ability and tools available. I used a small grinder to remove the aluminum above the bolt, gives it a machined look when all done. Install can be done in under an hour if everything needed is at your finger tips, plus tuning.

First time it will take at least an hour...maybe 2 just to get the correct tools out and the fuel line disconnected etc. After you do it once, I could do it in 30-45 min now no problem.

I did it in an afternoon. Not really rushing it, but could be done in little over an hour if you are used to working on engines. As I remember the hardest part was getting the fuel rails back in and aligning 4 injectors per bank to slide back in. Compared to other fuel rails in LS engines it is tight to clear the recess in the intake manifold because of the aluminum directly above the injectors. They have to stand straight up as you push them into the holes in the intake. Most other LT1 LS1 LS6 LS2 intake manifolds don't get in the way and the injectors can pull straight up. With the supercharger manifold it's a tight fit.

Thank you

How were your short term fuel trims at idle when it was pig rich?

Nice write up
Btw who has the best price on these injectors ?

They were hitting -25 STFT but there was alot more to it. I got it sorted out. On reset of the PCM it resets the FPCM also and fuel pressure runs at 65 psi at idle(and all conditions) until it relearns. Once it "relearns" fuel pressure at low load is 50 psi and the fuel trims come back into line where they belong.