A mates stage 3 setup running way too rich

[iceblade]

Hi guys, looking for some help really....
A friend of mine had a problem with his s13 (CA18DET pre-facelift non lambda) which we diagnosed to AFM fault by unplugging the standard AFM and the car ran fine....
He was then running a Horsham developments stage 2 chip etc before the fault so he thought he might as well upgrade to stage 3 as he already had my old known working/good 440 injectors and a known working/good Nistune with stage 3 map so he bought a Z32 AFM and we fitted it all up expecting it to work

Now the car struggles to start and is litterally throwing fuel out of the exhaust on idle where it is running so rich...... so as a test we unplugged the AFM and it ran fine....... I know what your thinking... faulty AFM.... this is where im getting confused......
We took the Z32 AFM from my s13 which i know runs 100% and put that in his car....and it was exactly the sameas with his fitted.... so i tried his AFM on my car and it ran stupidly lean!!!
put my AFM back on my car and its fine.... so im guessing theres somthing wrong with his AFM but the fact it wouldnt run with mine either has confused the hell out of me ...
Can anyone offer any advice on how we proceed next?
thanks for looking
Joe

[Matt]

It seems regardless of AFM used on his car, there is either a problem with the wiring when switching to Z32 or the tune (which apparently should just work with Z32/4440). Check your ECU is getting proper AFM voltage on the gauges from the AFM

Next is the AFM itself not working on your car. If its running leaner than the other one then either
(a) Element is dirty and not able to measure the correct quantity of air
(b) Z32 AFM is a chinese copy and wont work at all. See main forum section thread on dodgy Z32 AFMs

[iceblade]

Thanks for the reply matt, definitely not the tune as the ecu was running the same setup it another car 2weeks ago and definitely not a copy of a z32 arm as it came off of a z32 twin Turbo at a scrap yard that ran fine but had rear end damage... so I think we will clean the elements and check the wiring as suggested on another forum too
Thanks again
Joe
Oh the afm voltage at signal pin matches the nistune gauges too

[iceblade]

Well I'm running out of ideas now... I've grounded the pins c and d to the engine and to the chassis and cleaned the arm elements with Carb cleaner and allowed to dry and it still runs the same... any more ideas for me? Pleeeeeeease???

[iceblade]

Fixed it now..... he told me he had double tripple checked for boost leaks so I believed him as he has had the car for ages and knows how annoying they can be... found his inter cooler pipe on the cold side had popped off but was well hidden to be fair didnt realise a ball bearing t28rs could move that much air on idle.... too used to journal bearings see lol... that's why I didn't bother checking myself.. ah well I know for the future and now we know its cleaned and properly earthed now.....
Thanks again for the help

[TM_S13]

boost leaks... sometimes they haunt us like... I don't even know what...