Running lean

shorestyle

shorestyle

Fresh Recruit
So I'm running 1 bar on the stock ct9. I have a Blitz access ECU. I have supra 315cc injectors. SARD FPR set at 50psi. AEM UEGO wideband. And I'm running just under 13.0:1 under WOT at times.

Seems that when I take the car out for the first half hour or so I am running safe AFR's in mid to high 11s but after that my AFR's start to lean out ranging from 12.5 to 13.0.

My first guess is the fuel pump is not having a good time. Any ideas?
 
A

akis

Fresh Recruit
maybe thats your issue cause these ecu`s( i have a Jam Racing one) tends to run rich enough! whats the readings on full boost at high rpm`s?
stock fuel pump?
your FPR is high enough ( 3.5 bar!!)
 
churcherj

churcherj

Member +
are you running a standard or aftermarket manifold/cat or decat? if your running a stock manifold thats a big no no at 1 bar mate,

your fpr is set to enough, think its 3.1 bar or 45 psi to run 1 bar on a ct9 (correct me if im wrong) take it to a local tuner again to check it over and get it set up on a rr, they will confirm the fueling on the wideband
 
churcherj

churcherj

Member +
billybob said:
arent you not meant to run a fpr with a jam ecu as it confuses the ecu
Click to expand...

thats exactly what i thought when i first read it, thought the blitz is similar to the jam ecu, that its meant to be self learning and adjusts after a while...and commonly runs rich? so its strange its running lean....
 
A

akis

Fresh Recruit
My setup ( ct9 & hybrid) ~ 1-1.2 bar , is with stock Fpr aftermarket pump stock injectors and the Jam ecu fuels rich enough meazured with widband allover the band .. You use bigger injectors , fpr set high so i trust most possible pump issue
 
shorestyle

shorestyle

Fresh Recruit
I have a zisco mild steel manifold, 2.5" downpipe to 2.5" straight piped exhaust. So I have no problems running 1 bar on my setup. I was also under the impression that the blitz access ecu's tens to run safely rich since they're self-mapping.

Walbro 255 lph pump is on the way

Reps will be given when I'm not on my iPhone
 
JasonGlanza

JasonGlanza

Lifer
every Access was mapped for different setups (nt always known for which setup) so they tend to be slightly rich or maybe slighty lean it depends!
 
weeJohn

weeJohn

Lifer
A clean fuel filter will improve things a s well, the Jam website states that in capital letters in reference to the Jam ecu, Blitz will be the same.

I ran 315cc injectors with my Blitz Acess ecu, but could not get it to pass emmissions unless I turned down the fuel pressure, due to it being "mapped" form 295cc injectors.

If you have set your fuel pressure to have your idle correct, it will probably run lean at the top because of that.

Its a rrfpr that the Blitz does not like, ok with an adjustable fpr.
 
shorestyle

shorestyle

Fresh Recruit
maybe thats your issue cause these ecu`s( i have a Jam Racing one) tends to run rich enough! whats the readings on full boost at high rpm`s?
stock fuel pump?
your FPR is high enough ( 3.5 bar!!)
Click to expand...
These readings are all at WOT hitting 1 bar of boost.

A clean fuel filter will improve things a s well
Click to expand...

Fuel filter was changed in November.

I don't know if this means anything but playing with the throttle while stopped and watching the fuel pressure gauge, at idle it's between 45 and 50 psi. Doesn't have a consistant idle pressure really. Revving up the throttle pushes it between 50 and 60 psi. After letting off throttle it drops to around 40 then slowly back up to 45-50. Normal?

I haven't heard about these ECU's not liking aftermarket fpr's until now. I haven't had a problem with underfueling until recently. My AFR's before that were in the mid 11 range. Which makes me concerned that my fuel pump is just running out of steam.

Later tonight I will set my fuel pressure down to stock and see what happens.
 
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Fizturbo

Fizturbo

Member +
Upgrade the fuel pump,can you hear the standard fuel pump struglin,my mate had similar issue in his car after fittin fpr.
 
E

EP82 ON P

Member +
but u guys do realise the standard fuel reg (the main reason why it has a vac hose) is a rising rate reg (with a set pressure..not an adjustable pressure)...when vac pressure is in the hose it lowers the fuel pressure (for idle/decel and high vac situations) and on boost it raises the fuel pressure 1psi for each psi of boost in the hose.....if that makes sence...so im guessing if u had the ecu and u had ur reg set to 45psi with the hose off on idle it would probly run fine
 
weeJohn

weeJohn

Lifer
EP82 ON P said:
but u guys do realise the standard fuel reg (the main reason why it has a vac hose) is a rising rate reg (with a set pressure..not an adjustable pressure)...when vac pressure is in the hose it lowers the fuel pressure (for idle/decel and high vac situations) and on boost it raises the fuel pressure 1psi for each psi of boost in the hose.....if that makes sence...so im guessing if u had the ecu and u had ur reg set to 45psi with the hose off on idle it would probly run fine
Click to expand...

I agree with you that it is rising rate, due to manifold pressure reference.

There are fprs out there that increase the ammount of fuel above the stock levels as a cheap safety for increasing boost, thats the ones these ecus dont like.
 
shorestyle

shorestyle

Fresh Recruit
weeJohn said:
I agree with you that it is rising rate, due to manifold pressure reference.

There are fprs out there that increase the ammount of fuel above the stock levels as a cheap safety for increasing boost, thats the ones these ecus dont like.
Click to expand...
Yeah, it's a sard rrfpr but it's also adjustable.

The reason why I don't think it's the ecu is because this is the first time it's started to lean put this bad. And it's getting
worse and worse. I took it out yesterday and was slowly going from part throttle to wot and was nearing the 14.0:1 mark at wot. That's when I decided to not boost it at all until I put in a new pump.

The pump is really the only explination for running so lean. Like I said, I have more than necessary fuel upgrades for what I'm running. The 315cc injectors were flow tested before dropped in, the fpr is giving more than enough fuel. Fuel filter, although unlikely to be a problem has already been changed. The only upgrade I haven't done really is the pump.
 
weeJohn

weeJohn

Lifer
Would be good to change it, if just for its age.

Are you seeing this 14 value when coming on boost or when at full boost?
 
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