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Model specific boards => Golf mk2 => Topic started by: Diluxe on 24 October 2008, 17:00
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my cars suffering from a lack of top end power, can anyone explain how ignition advance happens?
its kjet ABF
fuel pressure and flow is good
cheers
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the ecu looks at MAP and RPM and looks it up in a littel table, it then advances the signal from the distubutor by that amount. while listening for knock if knock occurs it'll retard the ingnition upto 3 degrrees. still need to set the dizzy in the right place to start with tho.
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he mentions k-jet abf, I assume MK2 16v KR managment?
if so advance is controlled by ign controler in scuttle area, which has a vac line to brake servo pipe plus rev counter signal and coolant temp, should be a hall sensopr plug on dizzy. Oh and make sure you put the right dizzy on it, abf one wont work you need kr or 9a. no knock sensing so you cant run it on pap fuel unless you back off nthe ign timing.
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shows how long ago i gave up with k jet, last 16v i had had knock sensors but it was useing audi stuff
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ya was prob ke-jet? totally different kettle o fish and one i know next to nothing about, and dont plan to either. if you run k-jet go with the proper version, non o this this half hearted emmissions complient rubbish :grin:
if you want emmissions complience do it right, go abf :cool:
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i can make an abf ecu do j ket emissions. also whats wrong with haveing knock senseing on the ignition ???? ke jet fueling wasent used tho thats illegal
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just mean I'm not going to bother learning about ke-jet as I'll never use it, since adding all the extra emmissions stuff means you gotta cripple the engine wi lame cams. Unlike abf managment which can still make power! Not saying theres anything wrong with knock sensors at all, worth having if you can.
Not sure what you meant about ke-et being illegal? Was just guessing thats what the audi was running if it was running k-jet variant and had knock sensors?
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it was running parts of both. the final evolution of that engine actualy saw saab stuff, Ke jet fueling is even less optiaml than normal k jet henec illegal in my book
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ah i see, just realised by ke jet I meant erm motronic? basically the one fitted to the 2.0 16v 9a?
isnt ke the one which is on the PL, has a similar ign advance unit as the kr but with an extra lambda box? theres so many different ones around I get confused, drives my american mate mad when I give em the wrong name :grin:
we were talkin about the knock control box on this and it turned out it was actually a similar unit to the ign control as on kr but with knock sensor wired to unused pins, we theorised maybe normal kr unit might be able to do knock sensing but concluded it probly wasnt set up internally for it!
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i got lost after the first reply :laugh:
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whats the miximum advance the kjet system applies at WOT?
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thats all controlled by the box, ecu (well 1/2 ecu ) or electonic ignition module or whatever you want to call it.
inside is a prossesor whitch works out the ignition advance, from rpm, manifold absolute pressure, and possobly enigne temp so maximum adavnce depends on all of those, it'll proably be over 30 degrees at WOT when revving
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interesting about the manifold pressure, do you know where it woudl pick this up from?
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factory location is a vac nipple off the brake servo chunky pipe, the MK3 ABF has a connection close to the throttle body or iirc on the brake servo pipe depending on year
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Right so on the checklist,
I know my dizzy's good(brand new)
Temp Sensor Brand New
swapped ignition control thingy, no change so can exclude as possibly being faulty,
I just need to check this "vac nipple off the brake servo chunky pipe", is the chuncy pipe that has the vac pipe going off it to the back of the clocks & to the ingntion controller?
also I cannot actually see the big chuncy vac pipe terminating at the brake sevo end, do i need to look in the drivers side arch?
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yeah its the pipe that runs from the inlet to the brake servo. take the upper heat shiled out and you shopuld get a clearer view of all the vac pipes etc! its connected to the passengfer rear of the inlet manifold, cant miss it. follow this round and you'll find a black n yellow thing (non-return valve) with 2 vac nipples. 1 will go off to the mfa, the other will go to FEI (ECU) inlet, overrun cutoff and the other metal thing I've forgotton the name of. Check all the vaccy lines for damaeg, splitting and disconnectedness :)
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yep i've checked those lines, but its after the valve to the brake servo that i cant seem to follow , it seems to disappear somewhere just above the sevo, and i can't see how it attaches....any clues.
is there away to check if the valve is working, i presume if it fails, this would mess the system up?
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it runs to a plastic L piece which pushes into a rubber seal on the front of the brake servo, thats all :)
if this was playing up your brakes would be very hard as they would loose the servo assistance.
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lack of power up top is more than likely fuel related with kjet but it is possible for the Ecu is failing, it is rare but not unheard of for the MAP sensors to fail, have a look what the ignition advance dose with the vaccume connected and disconnected.