What is your AFR at idle when running injector size larger than 1000cc??


My setup relevant to this topic are:

- CTSC with AC @ 9psi
- RC 1000cc P&H injectors
- FJO injector drivers
- RC Plug and Play clips
- Kpro modded to use RSX wideband full time

I know most of your will already say that I don't need the 1000cc's since I'm only on 9psi, but I just want to say that eventually I will go up in boost as well as considering the E85 route, therefore I thought I would preemptively get the injectors needed now, so I don't have to do it all over again

The reason why I am asking this question is because after my Kpro tune, my car is running very smooth, and it cured the problem I had with the old standard CTSC setup at 7 psi where I would run as lean as 14.7 AFR in Boost because of that POS FMU.

So right now, with Kpro my AFR is great at both WOT(11.5-12.5) and partial throttle (14.5-15.5), except for when I am idling.

While my car idles, my AFR dips down between 13-14. This is a lot richer than how the stock ecu used to run at, which is around 16-18 depending on the engine temp. My tuner said that he did what he could to lean out the fuel at idle, but because the injector size is so large, he couldn't lean it out anymore.

Concerns I have: Is 13 AFR too rich for the motor at idle? Will it cause long term damages? Also, the obvious, I am wasting a lot of gas! I don't mind wasting gas if I'm driving the car hard, but not when I'm just parked at a red light!

So if most of you folks that are running same size injector is in the same boat as me, I will just suck it up, but if you manage to get your car to idle at a better/leaner AFR, I'd love to find out how you did it.

Thanks!!

 

my idle is at ~13.7

 

That may be one of the draw backs to having an injector that large. Proper fuel atomization at that low of pressure would likely suffer, that is what logic would tell me, however I have no direct experience running injectors that size and never will since I dont plan on getting into the 600whp range, you wont either with a CTSC set up. I assume your planning on going turbo down the road to make use of your current injectors.

 

Turbo, E85, full motor rebuild is all something I would consider down the road, just matter of saving up the money for it.

 

[QUOTE=S20004ME_PDX,Apr 30 2009, 09:03 AM] Turbo, E85, full motor rebuild is all something I would consider down the road, just matter of saving up the money for it.

 

FYI- there is a dude selling some rc 650cc injectors with the pnp clips so you dont have to cut your factory wires for $300. those clips are $80 so that a pretty nice deal. i would be on those if I were you and have your car retuned with them. This is assuming you cant find reslove with your current 1000cc injectors,with any luck you can since you have invested in them.

 

I actually am already running the P&P clips for the RC injectors, and at this point, I'll change out my oil in about 1000 or 2000 miles and see how it looks and go from there I guess.

At this point, I don't really have any extra money to invest in another set of injectors my next investment is to get a oil catch can / pcv system sorted out, because under boost, I getting more blow back than I noticed before. I'm thinking to build one instead of getting an off the shelf one because I want to include some sort of filter system.

Thanks for all the feed back you've given during this process.

 

Your welcome man, hope you get your stuff sorted out ok. You can smell your dip stick still too and see if it smeel more gas like then usual, you will notice it get grey or darker in color sooner as well if you have an issue with fuel contaminants.

Before you get a catch can for the pvc side, you can remove the front breather and put a filter on this and then cap it off at the intake, that will remove any possiblity of oil getting into your intake from blow by there. Thats the most simple and effective method for this.

You can run a Supra valve on the pvc side if you dont want to fork over the cash for a crank vent. You can pick up a generic catch can off ebay for $25 that will work just as well as any spoon for $150. Incorperate that between the pvc line and intake manifold to catch any oil under vaccume. The added crank vent or supra tt valve will prevent any boost from pushing into your crankcase. Problem solved and all for under $50.

 

What are u waiting for to go on e85? get a good pump and go tune