discovery 3 4.4 strange misfire

[birch 4x4]

hi we have a dicovery3 v8 come back because of what seem like a missfire or judder if you drive gently it drive exellent when you boot it there is a bad judder or misfire only on gas we have had this problem since the conversion . you do not have to boot it hard at all even as low as 2700rpms if you first move of from stand still it seem ok when you back off accelerator and boot it you get the judder.

its fitted with aeb- king electronics magic jet 111 reg. omvl injectors

ive beed told to select anticipate injection sequence in software and this stops the judder completely but it run uneven and lumpy when i watch laptop display . one of the banks over fuels badly to the point of stalling. like this

bank 1 bank 2 bank 1 bank 2

gas 9.34 ms 4.36 ms gas 3.10 ms 3.01 ms
petrol 4.63 ms 2.34 ms petrol 1.97 ms 1.95 ms
with. ant / injection / selected with ant / injection / not selected /
this runs uneven and no judder all power this runs exellent but it judders an all power

the regulator is small but its ment to handle the power
all pipe is nice and short too
has stated there is no judder at all with anticipate injection selected but it alter fuel badly on one bank.

with it not selected it run exellent but a bad judder


any help will be great john

[Tubbs]

Firstly are you sure all your injectors are corresponding with the petrol injector wiring ?
Are you also sure the banks are the right way round ? Swap the plugs over and recalibrate and see if it makes any difference. If you have the petrol injectors twinned with the wrong gas injectors then it will cause a very similar issue due to trying to trim the wrong bank. Im not sure if the king system calibrates at idle or rpm. If it calibrates at rpm it may still calibrate. If it calibrates at idle it will just stall the car ? Its a guess by the way.
Try and recalibrate after ticking anticipate injection maybe ?
You can also try and turn each injector back to petrol and see if it makes any difference. If you can make it go away by running one cylinder on petrol at leadt you can start searching for the fault. Or see if you can move the fault.

[birch 4x4]

hi we have now fix the problem .

the king aeb electronics . the injector markings where on the wrong plugs hence

a to b wrong way wround and e to h wrong way round i found it by lpg colour wiring diagram

gave it a full reset and tune for best fuel trims and turn off anticipate injection sequence.

was on the rigth banks just injectors wrong

and now it drives like new

[Tubbs]

Sorry, not excepting that as the answer ! I have personally fitted hundreds and hundreds of AEB components in my life and have never seen anything like that. Are you sure you hadnt run the injector cut wiring in back to front ? Thats more feasable. Because lets face it, if this was an actual problem that you say is a manufacturing issue then this forum would be swamped with king based problems. Which it isnt. So please dont run down AEB trying to make out that they would let something like that slip down their production line, through QC and into a box. Because it would just never happen. All AEB stuff be it king, zavoli, romano, emer, omvl is manufactured from the same production line. Just in different production runs. Its just not posssible im afraid. Pilot error with a soldering iron is though !

[tommo2009]

I agree with Tubbs, fitted many many AEB systems and of different brands and never seen that issue. As he says, fitting error not, kit error

[birch 4x4]

ive fitted aeb based lpg systems for years and lpg conversions for over 17 years we have converted so many lost count

im not nocking aeb at all i think there still the best on the market that fast to fit

all im say is the this one kit was marked wrong thats all to recap

all wiring doubled checked all fitted ok

the petrol injector connection right way out check many times

when you look at the gas injector loom connector a is all way yellow this was brown
when you look at the gas injector loom connector e is all way yellow this was brown

the injector connector loom covers wrong way round thats all . no big problem

so far ive not made a mistake on any conversion with petrol injector wiring in the past
and ive have had some omvl looms with bad earth connections in loom it self.

but i still think that aeb base lpg kit are best so far i used many types
we some times get back some e-gas conversions we convertered after some 20000 miles that have
developed bad connection on the ecu main plug thats due to a bad earth internal of ecu. over heating. pcb heating up becaues connection to ecu case has this is it heatsink
thay coma back after warrenty and ive repaired some ecus pcbs all burnt. bit fiddly to repair but cheaper .
ive once had to completey rebuild a romano loom that some one have damaged
and ive seen omvl looms with the soleniod wires wrong way round and the soleniods have a internal diode and soleniod over heating
ive fitted many king eab with no problems we use king base systems there cheaper than the rest of the aeb base systems . use many types but aeb can do the milage. we converted a range rover l322 many years ago with omvl dream 21 it did have a earth fault in loom we rapair it and that has clocked 98000 miles on gas and all it had is a set of recon injectors

i do not worry about faults problems ect at all there is all way a solution the trick is to find it fast and repair it saftly

many thanks john

[Tubbs]

John, no disrespect intended, but if you have been in the industry 17 years what are you coming on here asking basic questions about software settings and such ?
Surely you must know the Aeb systems as well as the rest of us old timers

[birch 4x4]

tubbs i agree with you ive converted a lot of cars over many years ect

but the problem i had with this car . i checked the complete convertion many times . the wiring /the pipe work keeping injector pipes as short as pos. most times when i gas a car it run ok even before i tune it. i have many types of software and keep a look out for updates ect . i try not to use anticipate injection sequence if not needed i find that obd connection helps well after you tune it then i tick obd and fine tune map keeping fuel trims best as pos.

but ide never seen a loom marked wrong before. so you don,t go look for it when you have a fault

but car seem to drive well now

tubbs thanks for your input on this case .if i get more faults you man to contact

best regards john