Greetings there,
First of all my name is George and im from Greece. I have some issues regarding the afr my mini runs.The mods on my min are 16%sc pulley and 2%crank pulley, alta cai, 4bar fpr with stock injectors, 63.5custom exhaust with stock header and no precat , ecu repgrog and GRS cooler.And i have an AEM wideband installed.
Now on the problem itself: When i accelerate with full throttle on 3rd gear(its actually happening on every gear) after 5000rpm the afr is at 13-13,2 and staying there while it is supposed to gradually drop and have 11,5 at about 7000rpm. BUT when i do the same, accelerating with 3rd gear but on half throttle it is working perfectly, therefore im having 11.5 afr at 7000rpm.So the problem is only at full throttle.
Im open to any advice cause im having trouble sorting this out for over 5 months now.Thanks in advance.

 

You need to upgrade the injectors. They are not up to the volume they need to be. Either that or you need a tune to adjust them. The 380 injectors are plug and play.

 

what is your rail pressure with just the key in ON position?
what is your rail pressure with it idling?

 

i will try that with the mechanic on monday i guess ill let you know.
Thanks.
Here are two videos showing what i mean. First one with half throttle:
http://www.youtube.com/user/apardan#p/a/u/0/8gwP_cxxhIQ


and second one with full throttle 4th gear if i recall right:
http://www.youtube.com/user/apardan#p/a/u/0/x9902OqYZoI

Thanks a lot for your help

 

not sure what the "rolling eyes" are for?
you wanted help for fixing your car........... I'm giving you the proper procedure to figure it out. While you are checking those make sure the fuel pressure regulator hose is hooked up to the intake manifold

 

sorry for the rolling eyes i missclicked i wanted to press and accidentally i pressed the rolleyes
ok ill check that out too thanks anything else?

 

no problem
start there

who mapped the car?
what injectors are in the car?

 

That's a ton of mods to not have bigger injectors and a custom tune/map....stock at higher pressure my help...but not sure if many tuners know how to adjust the maps for that..
Bet without one, it would run super lean....and boom!
Bring it back and get it re- tuned....I bet the last mod you put on it leaned it out a bit more ( if it was ever tuned).

 

Running on stock injectors with 4bar fpr.
Revlimit.gr tuned my car.
The funny thing is that the car was working properly when he first tuned it and for 3-4 months. But it suddenly got lean. I have changed the fuel pump with a new one 5 months ago but im often driving with the reserve fuel light on so it might have overheated at some point and i have cleaned injectors.

 

I have seen the new fuel pumps die very quickly when you run them low on fuel. check rail pressure to verify

check the fuel pressure regulator hose to make sure it's hooked up

most likely suspects

 

I really apreciate your help i will check these things out and i will let you know as soon as i have some more info..
Feel free to ask me any questions.
Thanks a lot. All of you.

 

Hello again, i made some experiments with my mechanic.
First of all the regulator is hooked up and it doesnt lose any pressure.
Secondly we put a gauge right after the gas filter under the back seats the numbers showed with key in on position 4.5 bar 65psi and idling 4.8bar 70psi. And then we went for a ride to check it under load, on full throttle it started at about 4.5 to 4.7Bar and gradually falling to 4.2 bar where it stayed till 7500rpm. Hope it gives you any info about my problem.impatiently waiting for your answer.
Thanks in advance.

 

your pump is probably bad, it should rise not drop under load
have a fuel pressure regulator there to check too but the key on position is correct

 

I just tried another fuel pressure regulator and its still not working... So it should be the pump right? Is there an aftermarket pump to buy?should i go for an aftermarket solution or the stock one?

 

The stock pump is good
Just don't run them low on fuel
It will kill the pumps

 

Your fuel injectors (330cc) are not enough to keep up with the mods you have. You can get away with the stock ones and a 15% pulley and some tuning. Anything beyond that, you will need to upgrade to a minimum of the JCW 380cc ones. You're pushing 18% total underdrive (16% + 2%), so you're pushing 16-17 lbs boost.

My best advice is don't tack out the engine. Keep it under 5000 RPM if you're going wide open throttle until you can get this problem fixed. If you don't, you're gonna pop a piston or two because you don't have enough fuel to cool the surface of the pistons. Or you'r gonna get detonation, and that's the bane of a boostfed engine.

 

Thanks a lot! ill install some 380s today and see whats happening

 

I installed a new pump and the result is rather good.Im just having a lean area in between 6200-7000 at about 13afr and after that it suddenly drops to 11.8 and it remains like that untill 7500. Sounds like another problem on my peripherals? i will install some jcw 380s today and go back to the stock fpr. Should i check anything else? like the throttle position sensor? what do you suggest regarding my lean area.
Thanks a lot in advance you are all very helpful.

 

No, you're in need of some tuning now. 13 AFR is dangerous for a boost-fed engine. Maximum numbers I've ever seen in a MINI is 11.8:1. Anything over 12:1 is asking for it.

 

so you think that my fuel supply is good and i just need a tune?

 

If you're getting 11.8:1 after that bad zone, then, yes, I would say tuning is in order. Your fuel maps are off. Jan at RMW can get elaborate better.

 

Thanks a lot

 

if you are reving to 7500 there is OBVIOUSLY a tune ON THE CAR
Get it remapped immediately..........

 

have you fixed the problem?

 

Actually yes, i have put some 380cc injectorz allong with the 4bar fpr and retuned the car and its working 11's now thanks for all your help