Fuel...ideas

[Room42]

I just put a walbro gss341 fuel pump in my car. The car started using stacks of fuel. I pulled 30!!! units of fuel from the power fc and it ran better. No extra knock. Still reads rich on acceleration on the narrow band. Sounds to me like a worn fuel reg. Any ideas?

[R31Nismoid]

Or the car was tuned with a failing pump.

And hence heaps of fuel was added in.

The reg is simple to test with a pressure gauge.

[Room42]

I had the injectors at 85 percent before and now they are at 75 percent. The idea that the previous fuel pump was lazy is good. It would explain random knocks on wot after holding it flat for a while. I'll do some more tuning and test some bits and see where it ends up.

[JonnoHR31]

you cant use the narrowband to determine how rich its running under accleration.... it could be lean for all you know

[Room42]

You cant tell how rich but you can tell if its either side of 14.7.

[JonnoHR31]

yer which is useless at anything more than very light load cruising

[R31Nismoid]

^ +1

Utterly useless off the stock sensor.

[Room42]

Not utterly useless but fairly useless. Obviously you arent going to run full load at stoich. Like I said it will let you know if rich or lean which generally is only usefull initially. After that its a bit like tuning a carby lol. Add more fuel till it loses power. There are stacks of variables to know when tuning a engine which I wont go into now. My point regarding the narrowband in this thread is that even after I pulled 30 of the entire inj map it still didn't run technically lean. You blokes know what I'm on about by now. That is heaps of fuel to take out. Shitloads in fact. It is definitely too lean now to give a hiding to for extended periods but it will get me to work till the datalogit and wideband arrive later this week or early next week.Try $30 a day for fuel and only doing about 40 or 50 k's. Ouch

Edited May 31, 2011 by Room42

[Room42]

you cant use the narrowband to determine how rich its running under accleration.... it could be lean for all you know

Read up on what rich and lean means mate. 14.7 is the middle, a lower number is rich and a higher number is lean. I did mention in the first post the gauge read rich lol.

[JonnoHR31]

i know how it works.... i meant too lean for the conditions, acceleration calls for a richer mixture than 14.7:1 (a narrowband simply tells you which side of 14.7 your on), so yer it might be on the rich side of 14.7 but still too lean for the conditions.

[Hanaldo]

i know how it works.... i meant too lean for the conditions, acceleration calls for a richer mixture than 14.7:1 (a narrowband simply tells you which side of 14.7 your on), so yer it might be on the rich side of 14.7 but still too lean for the conditions.

eg. You could be at 13:1 when it should be at 11:1, narrowband would simply tell you you're rich even though it's still too lean.

I follow you Jonno, I follow

[StealthX]

+ 1, jonno knows a thing or two.

[Room42]

i know how it works.... i meant too lean for the conditions, acceleration calls for a richer mixture than 14.7:1 (a narrowband simply tells you which side of 14.7 your on), so yer it might be on the rich side of 14.7 but still too lean for the conditions.

Agreed. Its on the safe side for getting me to work but not for flogging the crap out of it. Odd that so much fuel came off the map tho.