Heads, cam LS6 won't start with new injectors

[Too rich]

Firstly, I've learnt a lot from you lot lurking, thanks for that.

My C5 Z06 with an LS6 that I have just put a new cam (Torquer V4) in along with some other mods, yellaterra roller rockers, johnson ST lifters, CNC heads, UD ATI pulley, EWP, vararam, LT headers, cutouts

I decided to upgrade the injectors just in case I max the stock ones out to Ford SVO 30LB rated at 36LB for the factory LS 58 psi fuel pressure that I am still running.

I have got the car started and running with the factory injectors relatively fine, it will idle well enough to tune and doesn't still easily once it's warm and starts after about 3 or 4 starter cranks. It does smell very rich and has a reasonable amount of smoke at idle.

I bought some reconditioned SVO 30LB injectors off ebay and I updated the IFR, offset, short pulse adder and min injector pulse tables and didn't touch anything else from the tune that worked with the old injectors and it won't start. I can't work out if it's due to too much fuel or not enough, I have tried adding fuel using the VE table in the idle area but it sounded exactly the same.

Any help or suggestions very much appreciated.

Stock injectors - ran fine.hpt
SVO injectors - no start.hpt

[abc]

I assume the experienced guys with the understanding of injector data are gonna tell you the same thing, why cheap out on the injectors now? You need the proper injector data in HPT GM format to make them work, do you have that? Either you have the wrong data, or the injectors are junk, maybe both. The engine does not care what injectors are in it, as long as you have the correct data, when it comes to low/light load scenarios, so... if you had the correct data and the injectors were of good working order, it would act exactly the same with the stock injectors vs your replacement injector as far as the start and idle goes.

There are plenty of good factory options with the data readily available, that are inexpensive enough to not goof around with "reconditioned junk". Do yourself a favor and buy new, good injectors with the proper data.

[Too rich]

Thanks for your feedback, you're right I should've gone with brand new injectors from the start. The main reason I went with the recon set was because the injectors are proven to work well in Gen III"s and the injector data is readily available and to the best of my knowledge I have got them tuned right so I'm going to assume that the injectors themselves are junk.

I've found some that flow 41LB/h hopefully that's not too big to get a good idle.

Do you know how to calculate injector duty cycle on the scanner. I've got IDC = Pulse Width * RPM) / (120000) * 100.

[gtstorey]

Do not buy injectors from eBay, Amazon or Facebook. Only from a well known supplier that supplies the data for GM format or GM injectors.

[gametech]

Thanks for your feedback, you're right I should've gone with brand new injectors from the start. The main reason I went with the recon set was because the injectors are proven to work well in Gen III"s and the injector data is readily available and to the best of my knowledge I have got them tuned right so I'm going to assume that the injectors themselves are junk.

I've found some that flow 41LB/h hopefully that's not too big to get a good idle.

Do you know how to calculate injector duty cycle on the scanner. I've got IDC = Pulse Width * RPM) / (120000) * 100.

Injector duty cycle is a default math parameter included in the scanner. No need to do your own math. You just need to be logging pulsewidth and rpm in the channels. As for any injectors being too big to idle, remember that some factory flex fuel trucks come with 50lb injectors that idle good enough to meet emissions standards on a smaller motor than you have. Many of us run injectors over 100lb and have no idle issues. The key is quality injectors matched with proper data.