bogging/missing until you lift off throttle and go back on it

[PeteG40]

It might be different if tom has 8- 1 pistons if map is for 9s

[Etches]

Hmm yeah possibly Pete , I have the 8:1 pistons with the metal HG .

Andy yeah that sounds good mate, makes sense with the max boost pressure as I've got it at about 0.5 Bar to run it in. 300 more miles and I shall crank it up to a bar and we can talk about getting a chip sorted then a mapping day.

Cheers Lads

[Andy]

It might be different if tom has 8- 1 pistons if map is for 9s

Thanks for the advice Pete, but Tom's variant of G40008 is for 8:1 CR - have a few 'favours' of each map so can tailor them to spec. 

Edited to add - the transition to boost on all the turbo'd G40s can vary a bit depending on cam timing, actuator spring etc. etc. When doing a custom map it means that the light throttle/low boost area of the map often ends up having a lot of tweaking to the spec to fully optimise.

[PeteG40]

knew you'd be on the ball andy - just a suggestion! wasn't sure how many wossners youd mapped

[Etches]

Got my MOT done yesterday , failed on a couple of things including emissions ,



AFR showing 15 on idle , didnt think it would be that rich

[Andy]

I think there might be a problem with your lambda. You say your gauge is reporting ~15:1 AFR at idle, and 14.7:1 is the ideal - anything swinging between 14.5:1 and 15:1 or thereabouts is normal.

However, the MOT man's probe is stating lambda 0.778 at idle - which is about 11.4:1 AFR! They don't match...

[Etches]

Yeah, ill need to adjust it on there gas analyser . Weird thing is Co pot adjustments arnt changing the mixture  , I'm getting a reading across pins 1-3 so surely the variable resistor is working . Room temp sensor pins 2-3 show 2.3k ohms

[Andy]

I think there's a fundamental setup or lambda probe issue here.

Your wideband lambda is reading differently to the MOT centre's gas analyser.

[Etches]

Ok Andy, I shall just set the CO pot to a known decent value and get the wideband adjusted (if it can be) to their readings.

[Andy]

Are you still using the standard narrowband lambda?

[Andy]

Ok Andy, I shall just set the CO pot to a known decent value and get the wideband adjusted (if it can be) to their readings.

You have two faults to fix, possibly related - but maybe not:
1. Establish why the car is idling so rich. (Are you using the stock narrowband lambda still?)
2. Re-calibrate your wideband.

CO pot is for fine tweaking, not massive adjustment so it won't help you much here. I think you have a fundamental setup issue.

Are you still using the standard narrowband lambda? Is it known good and working?
Is the blue temp sender okay?
Which 250cc injectors are you using? Genuine G60 ones, or are they Ford 'motorsport' ones?

[Etches]

Brand new bosh lambda , known working blue temp sender , cleaned g60 injectors.

[Andy]

I'd run through the diagnostic guide on here checking everything back to the ECU connector pins.

11.4:1 AFR on idle is cold-start levels of richness. Do the engine revs rise when you unplug the blue temp sender?
Is the lambda probe earth connected?
Is the closed-throttle switch working?
What's the blue temp sender resistance measured at the ECU pins?

[Etches]

Yeah revs do rise when its unplugged, the lambda has been earthed . I'll have to have a look when I pick the car up from the test station tomorrow regarding the other stuff. Cheers Andy

[Andy]

Other possibility is that the MOT man didn't wait until it was warm... They should wait until the fan cuts in and then test after the fan has gone off.