VN idling ruff, backfiring, loss of power, guzzling fuel

i've tripped the computer and the 'check engine light' just stays on. i tried resetting the ECU by disconnecting battery, and i tripped the ECU again and got code 12, then when i run the car for a bit, the engine light comes back on, and we start having problems, then i trip the ECU and the light just stays on and doesnt flash a code.

i just had another good read of your first post (which i usually dont do lol) the ecu light staying on when your checking for codes in a bit weird.... but otherwise still sounds like the cas, one of the coils or dfi module. splashing water usually cures it for a short period but some dont respond at all.

get a video and ill be able to tell you if the motor is misfiring or not.

 

and if it wasnt missifiring before u poured water onto the dfi and coilpacks. it may just be now

 

I had a simular problem, turned out it was lack of fuel pressure and i replaced the fuel pump and sender and it fixed its self, might be something to check but yeah, really sounds like the CAS keep trying to check for codes might work one time. good luck

 

water temp sensor effects your AFR, will make it run rough. obvious signs are smoke out the exhaust n fouled plugs.

 

how did u go mate, i have the exacy same problem, do hear a clibking noise from the BCM?

 

Engine fan fuse melts?

Sounds like you have a definite electrical problem

Wether the fan being faulty would cause all that I dunno.

So if the fan isnt running the motor runs fine ie: no backfiring etc?
If so then a short or something in the wiring or the fan motor itself might be faulty which may I guess cause problems with the ECU ?
Take it to an auto sparky and get him to check why that fan is melting fuses. Or at the very least disconnect the plug for the fan (Left side of radiator when you open the bonnet) and check the terminals are clean. Not uncommon for VN-VP's to fry this plug. I think it gets moisture in it and corrodes and eventually there is enough resistance at the terminals to heat the plug up.

Flames out the exhaust sounds a bit full on too.

BCM is the Body Control Module. Usually located near your accelerator pedal behind the plastic kick panel.

 

when you dont have a chip in or a faulty chip the car goes into limp mode, the fan goes on (as you said) and it runs like dogs balls, enough to get you home (hence "Limp" Home).
it sound like as mentioned above, your ecu is dropping a connection and going into limp mode. change both chip ecu (if you havent already) and go through every single fuse and relay on the car, but just remember that throwiong money at it aint gunna help, you can pick these motors up with loom for 300-350

 

i have a simmilar problem the idles a bit rough, its chewing through both gas and petrol, it backfired a couple times and eventualy for no reason it wouldent start on the odd day. one day i was at work and it didnt start and we replaced the coil pack and nothing so then we changed the crank angle sensor and she fired straight up. after that we got it tuned but the idle and fuel acconomy are still s**t. besides that its been fine but yesturday four weeks later it wouldent start took us half an hour to start it.

basicly fuel economy and power are crap so i suppose ill try ecu aswell see if it makes a differance. thanks anyway

 

Try a new ECU first because when the new chip was installed it could of messed up some of the components around it with static damage or heat or simply an incompatible chip.

If it was working fine before the chip then those sensors should be fine

 

the chip is the problem

i got a stage 3 chip 4 my s2 vn berlina bout 3-4 months ago and it only had just been starting to give me problems lately coz of this hot consecutive weather...the chip stuffs up the way the car usually distributes fuel and reads temp ect... thus that extra burst of power u first get when u put it in...ova time this becomes to be a problem...

i had these same symptoms with my car when i had the chip in... back firing loss of power and stalling, high low revs ect... thought it was an engine prob...took it to my cuz the mechanic ... engine is a1... i took the chip out, car perrrrs like a kitten now... so there is the fix...no chip no prob

but don't get me wrong the chip was good while it lasted... so if u want that power ur better off goin to get it professionally tuned... shouldn't stuff round wiff cheap enhancements... that is all

 

aka get a foamy tune not an ebay resistor