Hey guys need some gurus help, been trying to diagnose my car myself to save some dollars..
So my 2004 vz alloytec randomly started to run like crap after driving along the highway, after coming to a stop at home it was idiling pretty rough, I checked the car the next morning and started Fine etc, after driving it for about 10-15 minutes it began to misfire again… I then began my diagnostic side of things by checking coil packs… I came across bank 3 coil pack being faulty and not working… I then replaced it with a new coilpack… car started and drove fine about about another 10-15 minutes and the misfiring came back but was intermittent misfires wasn’t consistent… then eventually it came back as before and became consistent … I then Began to check coils again and some how it was the exact same one… I then changed spark plugs and gapped them to 0.7 as recommended by my mechanic and switched coilpacks over with a different one… then after the misfiring has just become consistent from start up and still from bank 3 the coil unplugged is making no difference… I then began to dig deeper and changed the injector around to see if it switched which coil it would misfire from and still hasn’t made any difference…. I’m lost in what I have to do right now…. Car was running absolute perfect till now… please help
Hi mate. I had same issue until it finally died on me. Before it rolled to the curb for what could have been its last time I have had at that point had a platoon of Mobile mechanics from the same company mauling the car. It went on for over 3 months.. All of them did the same thing systematic elimination and using their expensive test module computer gadget. He changed DFI module. Worked, I paid him and it stalled in the city at the traffic lights that same day. Tow truck $100.
New guy same company replaced Crank angle drove it. It started I paid him. I drove it a tidy 7 klm and it stalled on a roundabout. Dirty looks from everyone. Tow truck back to home.$120
Called same company different guy came out, Changed Cam sensor started paid him drove it about 1 klm stalled wouldn't start. Tow truck $100. Phoned company, not one but two Mobile mechanic graced my driveway from the, same company... One changed out the new DFI module again and applied more grease to it. The other checked the fuel and manned the meter for faults couldn't understand what they were saying because it wasn't English. Said DFI was faulty because it had heated up. Showed me scorched metal plate. He replaced it didn't charge me for new one but charged me labour. (he said it was under warranty ????) Total Costs at this juncture was over $1600 These two were the 4th visitors and it looked promising as it ran sweet as a nut on the drive. I slept easy that night.
Car failed next morning. Crank but no start. I called the same company. Had to get taxis to and from my appointment in the city. The car sat on the drive for 6 days as the mobile company owner said 'it was a holiday and I would have to book on line'. Grrrr.
The newest caped crusader came out after 4 days waiting. The mechanics seamed to be getting younger each time. He followed the same routine as I watched eagerly this pre choreographed explanation of what he was checking. Same as the other guys but the diagnosis took a turn for the worst now as its ailment progressed to another part of the cars anatomy. He showed me the fault readings that had now populated the screen and after stating that errors were ABS, cam sensor, ignition mass air intake. He said more than likely the BCU under the dash. Then went onto say the car would have to go to THEIR workshop and do I have RAC call out? It was at this point I suddenly realised they were not getting younger I was getting older and the car was back to its original position, a non Fn starter.
I told him at that point that mobile means he comes out and fixes the car. I then said to him. 'just leave'. Sent him packing. Lost my sht and told him to tell his boss that its a scam keep replacing a part each time and charging me labour every time.
Anyway, I got onto THIS site and I saw the same issue over and over again all on the older models all related to coil pack BCU sensors ect etc . So I did a quick look over the Wiring block connection to DFI . II saw on this website (see pics below) and got out my cheap and nasty multi meter. I turned ignition on and tested the green wire female connection in the block. 'Hello' I said . 'No reading'. I sprayed some electrical cleaner down the end of the sucker and used a fine piece of wire on the female metal block careful not to damage it. Pushed the parting bits back to a square shape There was plenty of crap on and in it. I pushed the little blade that holds the male part in place on the small metal square back into its position very carefully and put it back onto module.
Well f*&^% me, it started first time, rev counter static not fluctuating and hasn't stalled once for over 2 months.
My advice is check the 12 volt feed wire FIRST (Usually green wire nearest). Judging from info on here cars start and then stall under load or decelerating at lights etc. This design is crap and that 12 volt feed is the one that heats up. Apparently that wire in the block provides activation for DFI ignition system to BCU and sensors and is obviously prone to bad connection that sends out intermittent voltage drops to BCU. It arcs and causes it to heat up spread more and fail. Thanks to the guy that posted these pics and his own story similar to mine that set me on the straight and narrow. (Bought second hand one just in case for $20 ) AC Delco were asking telephone numbers for a new original. Like anything this little gem of info is that block requires maintenance.. it shouldn't, but it does Good clean and reseat the little connection ends to snug fit on the DFI module pins.
Hope this story helps.
PS. It may well not be the DFI wiring block so if not and you are in an emergency try this for BCU failure.
If your car doesn't start take out Starter relay turn on ignition. jump wire across relay points. If it starts remove wire immediately if it stops you will have to take key out and do it again turn key to light up dahs repeat. watch this Youtube and follow instructions to the letter.
Works in most cases as it bypasses the BCU computer if that is the issue. You can drive the car but if you stop it you will have to do process again.
). The fact that the fault seems intermittent, seems to indicate an intermittent wiring issue or an ECU fault.
