Hesitation Problem - Blazt Package Used, Queries?

frp

frp

Member
cheers ed I actually understood that!
I see what you mean the over fueling could be the cause of the problem. ill have to make matt at trl aware of this next time I'm there. would I be right in saying that this could cause minor power loss?
Also Ed what you were saying about injectors being small, they are 550/600cc I thought they would be ok for my power?
cheers
steve
 
Fusion Ed

Fusion Ed

Active Member
Ant, I have replied.

Steve,
Anything over around 11.5:1 is probably going to start to loose power, it varies but around there anyway. What you are getting I bet is when you leave the close loop areas (shown again below -flip it to correspond with your map) you get a sudden jump to very rich cells. You will almost certainly feel this.



You were not clear weather you have larger injectors already fitted? Or do you just have stock ones with higher pressure? You cant surely have 550-600 on there already with no fuel computer? (sorry I don't know your spec) In any case as an example of required sizes of injectors, Allen was totally on 100% with 800cc injectors to get the 463 bhp at 11.9:1afr, using stock fuel rail pressure. 440cc at the same kind of duration will see 320 ish bhp. You should roughly beable to scale between them to see what's good for you.
 
antgtir

antgtir

New Member
Ed: Thanks for the advice, i will look into what you have suggested, fingers crossed this issue will be sorted once ive done what you have suggested.

Ill keep you updated.

Thanks again.

Ant.
 
stevepudney

stevepudney

GTiROC CHAIRMAN
Staff member
Micra Ed said:
Kenny thats not right. AFR base is the correction value used to attain lambda=1 in closed loop. Its just having to remove a load of fuel to do so. If the lambda sensor broke the ECU defaults to AFR Base = 100 and THEN it will run pig rich. I should add this would be whilst in closed loop. Once out of it i.e. full throttle it will use only the fuel map with temo correction and chances are again you would be very rich. (kenny would be right here, although I dont think you would be less than 10:1 or it would struggle to even run.)

THIS I should point out is a VERY Clear example of WHY you cannot map for closed loop operation. The stock ECU is VERY good at correcting its closed loop map to protect itself and the engine from being too rich or lean. And since your in closed loop even at 70 on a motorway its impossible if your sensors are all working the way they should be to kill an engine from either over or under fuelling.

Anyway, back to this. The AFR base works like this 100 is no correction. Greater than 100 the ECU is having to ADD fuel (i.e. base settings are too low, fuel pressure or injectors blocked/too small) if your less than 100 injectors are too large or fuel pressure is too high.

90-105 is acceptable. Ideally you want to be on the richer side of 100 rather than the leaner side (100+)

And Steve YES I would say that IS why your car is behaving odd, almost certainly. Timing is normal for the data you have provided, assuming your timing is set right. Although I would need to see a data log as it looks as though your probably going off the load mapping on your fuel map on full throttle (not ideal). I would possibly risk suggesting that the car has been setup with external aids without being done at the route source (i.e. the ECU) and so your suffering because of it.

Ant, send your log to info@fusion-motorsport.co.uk and I shall take a look for you.

Ed
Click to expand...

Thats interesting to know, I had never really thought of it like that.

So would that mean that with the EManage being a piggy back off the stock ECU, on part throttle and alll things mechanical working as they should be, it would be pretty impossible to kill the engine from over/under fuelling.
 
Fusion Ed

Fusion Ed

Active Member
hmm yes that's exactly right. If it was wrong however what you would get is a lumpy transition from closed loop to non open loop as Steve appears to be getting above, but for 99% of the time the ecu would have self corrected always making sure things are as they should be, as this is pretty much the time you spend in closed loop.
 
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frp

frp

Member
High ed my injectors ar 550s i think (maybe 600s) on the stock fuel rail and i have a safc II and avcr with std ecu running 1.6bar max @372.3hp. Fuel pressure unknown.

steve
 
Fusion Ed

Fusion Ed

Active Member
Ok Steve makes sense now. The injector correction on the S-AFC is wrong. If you change the over all correction so that the AFR base is about 90-95% when holding the throttle at about 2000 rpm in idle you may find that your problems disappear. Although you will have to check that the top end fuelling is still ok. I cant help but feel however you would be better to change to something more flexible be it perhaps an e-manage which give you 3d maps as you will still be able to play and learn from it the same way.
 
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