blitz imp reza

Have fitted an AFR recently and have noticed that it is leaning out in 5th :-(
Have uprated fuel pump fitted already (sytec).
Is it that the standard fuel regulator is set to low for the pump? and/or
Bigger injectors needed?
Am going to change the filter again anyway.
Or is it not mapped correctly, showing very rich in 1st-4th though so dought that, running about 15.5 psi.(1.07 bar)
Also getting a bit more MPG out of it since I changed the pump....hhhhmmm
Its a MY96 uk saloon with a TD05 turbo.Anyone had similar experience

Delboy2

Sounds as though the pump may be over-running the standard Fuel Pressure Regulator.


Cheers

blitz imp reza

Surely if I am leaning out then this is a flow probelem rather than a pressure problem?
As pressure is defined as restriction to flow.
Or is it that as the pump operates at higher than standard pressure the fuel regultor is know having to drop alot more pressure to run the pressure it is set at and hence loosing flow through the regulator instead of going to the injectors?
Just trying to understand the relationship with pressure and flow in the fuel sytem.
Can anyone enlighten me.....

Delboy2

Here is some information regarding uprated pumps :-

Note, however, that using a 255 or 255HP pump will probably require an adjustable aftermarket Fuel Pressure Regulator. Any very high flow pump can overrun the tiny stock FPR, causing the base fuel pressure to be higher, and making the fuel curve nonlinear, making the ECU's control of the fuel more difficult. As the new pump is capable of delivering a much higher fuel pressure it is possible for it to overcome the Oem FPR's internal spring thus causing the diaphragm to lift therefore lowering the fuel pressure but increasing the recirculated fuel flow back to the tank.

Cheers

blitz imp reza

Thanks for that, as I thought above. Just like to understand what is happening before chucking money/parts at it.

StickyMicky

lambdas heating up as you go through the gears and is showing a leaner mixture then actually is?

blitz imp reza

I can see your logic sticky, but am pretty sure the above will hepl me out.
When priming when ignition turned on I can here excess pressure being dumped back to tank (must be from FPR), did not do it with the standard pump.Took a while to figure it out, strange noise when it echos through the car.
Shame I did not get the AFR before I fitted the uprated pump as planned, would of gave me a benchmark for comparison.Will bare it in mind though, thanks.

EMS

That is true and probably the reason for your concern.

Mark.

The_Judge

Are you still using the standard ECU? If so, you could have maxed out the fuel map, as the ECU isn't expecting so much air to be flowing. A knocklink would tell you for sure if you're excessively lean. Pray that you aren't (and haven't been) though...

blitz imp reza

Standard ECU, with a scooby ecu in the spare socket running around 15/16psi.
Want to get to the bottom of the problem. I ought to fit the uprated regulator anyway as I found out the pump I fitted was the motorsport version not just an upgrade.
And will go from there. If the lambda does warm up that much that it gives a false reading what is the point in having AFR meters???

StickyMicky

i was told to try this by bob rawle

drive nice and slowlly in 4th gear for about 10 mins till the lambda is cool and then floor it from low revs and monitor the afr, i used a scoobymonitor which shows me the lambda voltages so its a bit more acurate, but the same test can be preformed on yours with a afr gauge

i find that it doesnt really take much to heat the lambda up so that it starts to show lean

blitz imp reza

Will take note and see what happens. seems ok in forth no matter what I do from slowish or on WOT through the gears.. but not 5th at the mo!
Will try it out anyway cheers sticky
I have the new dawes device which is calibrated with voltage settings provided from people on here apparently. This is from web page, think it is the scoob settings rather than the standard settings but not 100%.
http://www.j-w-racing.co.uk/acatalog...tio_Meter.html
First light: Red= .78 to .90v
Second light: Yellow= .90 to .94v
Third light: Green= .94 to .98v
Fourth light: Blue= .98v and up
Will get this confirmed.
I am in the blue most of the time in the other gears. Occassionaly had green and tiny flicker of amber, but red in 5th so backed off.

blitz imp reza

Ignore above settings they were for standard, theses are the ones.

1st light (red)=.79v-.83v

2nd light (yellow)= .83v-.85

3rd light (green)= .85v-.87v.

4th light (High Intensity Blue)= .87v to limit of O2 sensor

The_Judge

Does the ScoobyECU take into account you're running a TD05...?

blitz imp reza

Its a series 1 so the TD05 is standard... Should of left that out at the start confusing sorry.
Still trying the heating up theory, trying to find a stretch of road safe enough to wind up from slow in fifth instead of 4th as mentioned above.