erggy

it looks like it's the fuel pump issue...I checked a couple of things to pinpoint the issue

1. spark plugs: all have the same color, so injectors should all be working at the same rate. the plugs look lean. So i wapped in a new set of BPR7ES NGK plugs as the old set was quite old

2. piping after MAF before the turbo: no leaks

3. rechecked AFR with Motec PLM sensor: just to ensure that my AFR logged by LM-1 is correct. They are almost identical.. lean!

4. Fuel Press: Put the fuel press gauge in and fuel pressure drops after around 4,000 rpm to about 3.2-3.4 bar (idle is at 3.0 bar... so full load should be 4.2-4.4 bar)

so it led me to believe that fuel pump is the issue....

Actions taken: swapped in walbro fuel pump and then checked AFR... AFR is now really rich... after peak torque AFR reads around 10.2-10.4. Before the walbro my 3rd gear reads 11.8-12.2 AFR

now.. my question is... after swapping in walbro, do I need to change anything else except the fuel maps? Any rescaling/adjustments of other maps required?? sorry.. very noob

Mad_SB

iTrader: (8)

Good trouble shooting man

You just need to get the fuel table sorted. Once you get the afr to a comfortable point you can start working on the timing.


Working with the stock knock sensor can be a pain, but it has saved countless evo's from self destruction, including mine when I had the injector failure...

erggy

can u share w/ me what happened and how did u figure out it was an injector failure? curious.. thanks!

RoadSpike

iTrader: (5)

I believe an easy test is to pull the plugs and get a light and look at the piston tops for color differences.

How's that tune going btw?

Mine posting up your AFR and fuel maps?

erggy

Would the plugs be able to tell if one particular cylinder is lean? I tried but it's quite hard to look at the cylinder head from that small hole.

I haven't retuned yet after swapping in walbros, will be doing it this sat... will post maps and logs for your comments again. T hank you!!

RoadSpike

iTrader: (5)

Yeah it isn't easy to get a good look at the top of the cylinders one of those LED pen lights seems to be bright enough to make it visible.

I wonder if pulling off the manifold and looking at the exhaust ports would be equivalent..

erggy

hi guys... did some tuning after installing my walbro fuel pump.

I've attached a before & after data log of the tune.

Comments pls!!

RoadSpike

iTrader: (5)

Looks like you cured that knock problem good work

sub7

Sorry, I was looking at the log files but I can't figure how you guys could tell so much thing by reading the log file?

a) LoadCalc, how can I translate into PSI? I assume this is boost right? Evoscan shows eval=5*513*([InjPulseWidth]-(-0.1026*[Battery]+1.8741))/[AFRMAP]
b) How can we tell the gear pulled from the log file? By TPS?
c) What is AFRMAP? When idling, it shows "128" consistently until TPS/RPM goes higher than normal (eg: 30% TPS or 2600rpm)

Btw, I have similar problem with erggy but it wasn't the fuel pump causing my car to lean out (close to 20 AFR after 4000rpm!). Some workshop took the power line source to my fuel pump to install my alarm! When there isn't enough power to supply fuel above 4000rpm, the car goes lean... lesson learnt!

Thanks!

TouringBubble

iTrader: (2)

PSI based on load is basically a guess, but if you've tuned for a while you learn what load values equal an approximate boost level on various turbos. There is no direct translation.

You can tell the gear by the speed and RPM.

sub7

Say, I got a TPS of 70, RPM5250, MAP 3.25496, LoadCalc 227 and WB02 11.5, can I safely assume am running on 17psi?

I'm assuming Loadcalc 0 to 100 is vacuum while 200 is 1 bar (or 14psi)?

TouringBubble

iTrader: (2)

That calculation is probably close, but I don't think there is a definate 100 = 0 and 200 = 1 connection. For instance, when you change cams yo hit higher load levels earlier without much boost increase. It was originally thought that the load% was actually a KPa value, but I think that's been disproven.

Read through some of the boost tuning threads, such as the WGDC logging thread, and look at the graphs posted there. Most will have a boost and load curve mapped and it will give you a good idea of how they are related.