Just a bit of advise guys, Am I right in thinking if I go for a larger intank pump, Ie 290LPH or 310LPH pump that all excess fuel that is not required gets returned into the tank or will I need a map tweek to scale the fuelling down, Ive got Delta dash and an AFR gauge so I can monitor it but just thought I'd ask.

 

Hi Gaz

Have look on this thread

https://www.scoobynet.com/general-te...p-mapping.html

You can log the AFR with Delta Dash and you will see if will need map tweak,speak with your mapper


Jura

 

Thanks Jura, gonna be speaking to my mapper anyway but just thought I'd ask the question first, Might just go with a new 255LPH for the power I'm running,

Does anyone know what LPH the MY03 Spec-C fuel pump is as standard, I believe it's different to the STI one?

 

Thanks Jura, gonna be speaking to my mapper anyway but just thought I'd ask the question first, Might just go with a new 255LPH for the power I'm running,

Does anyone know what LPH the MY03 Spec-C fuel pump is as standard, I believe it's different to the STI one?

 

You can log the target afr but not the actual afr with delta dash as the ecu cannot measure it.

Changing to a higher flow pump could make it richer and therefore safe to do if thats all it does but you will lose power, if the old pump was struggling to keep up you will now have a lot of extra fuel if the previous pump was struggling when mapped. Therefore its best to get it checked.

Have also seen a higher powered pump overpowering the fuel pressure red at low consumption times like idle and cruise therefore making it rich then. However the cruise and idle closed loop fueling it pretty good on your ecu, however if it is overlly rich the ecu will temove fuel from the overall map compensation and make it leaner on boost.
Therefore would highly recommend getting it checked.

 

Thanks for the reply Simon, I've an LC-1 fitted so can monitor it, Regarding the Delta dash can you not view the AFR's by getting the lambda figures logged and multiplying by stoich?

I think it's still on its original pump and was mapped in 2006 so would have been good and up to the job in its day so shouldn't have an issue there, Only reason I ask is that my defis are on differential fuel pressure and anything over 1.3bar of boost was dropping around 0.7 bar of pressure, when on relative pressure it's loosing around 0.5 bar at the top end, Just wanted an easy swap over for a change, lol.

 

Sounds like fuel pump is failing to keep up then.

What afr on the lc1 you seeing on boost at high rpm?

The ecu doesnt have an accurate way to read on boost afr, the sensors and setup is all geared towards cruise and idle emissions

 

Ah right now I get you, To be honest it's only just started giving a warning up on Defis, I'm pretty sure it's in it's early stages of fuel pump failure personally, Checked vac pipe and OEM FPR and its all good there so leaves me to think its the pump, I'll check the AFR's later when I get back from work, From memory they were around 11.2(ish) on full boost up the RPM scale, I don't suppose you know off the top of your head which block and pins the LC-1 got to in the ECU as I can log it then, It's was the last thing I needed to do, It's a MY03 Spec-c Ltd,

Gaz.

 

Dont believe standard ecu is able to log the lc1.

Use the lc1 laptop software to log it.

11.2 is fine.

 

Sorry mate, didnt explain myself properly but having thought about it can i just plug the LC-1 into a COM port on the laptop and log through Deltadash with it?

11.2 is what it was before defi alarm not had chance to check yet but i know if it goes above 11.2-11.5 ive got issues with my pump, Not done that many miles but its knocking on a bit now

 

As I said,I would speak with your mapper first and go with his recommendations,but as Simon said,will needs to be at least checked


Jura

 

Well it got gradually worse on boost and ended up seeing high 11`s(for the short time i was testing it) but was fine on idle/cruise, So got another pump sorted and decided to whip it out this afternoon and replace, Glad i did as now i am seeing low 11`s again now on full boost, Happy days

 

Nice one