Cammed VP V6 won't start. WTF only changed the oxy sensor

[agrsv8]

Hey PPL,

Okay so the VN with the cammed VP V6 won't start, was running fine until the engine light started intermittently flashing, diagnosed it, was the oxy sensor, changed that, all good ran fine, next time i went to start it, running on 4 maybe 5 cylinders, WTF, changed the coilpacks and ignition module, has happened to me before, still no good, diagnosed it again, code 12, (satisfactory) umm no computer WRONG, it won't start...resistance checked all the leeds, checked the spark plugs (no fouling, gaps rechecked, they were a little wet from fuel from trying to start it sooo many times, checked the injectors (no clogging) fuel pump works fine, swapped relays around to eliminate the EFI and Start relay, still nothing, swapped the MAP with another one still no good, battery is practically brand new (century)

SO there is the bucket list of SH!t i have done in the last 2 hours, Bugger me i can't figure it out, I'm thinking computer is rooted.

Anyone had this before?? throw some ideas at me!!

Cheers

[SweetWagon]

Have you tested for spark, injector pulse and fuel pressure? They are really the only things it could be, if your not getting injector pulse or spark could be your CAS

[agrsv8]

yeah i'm getting spark and injector pulse, i don't have the equipment to test fuel pressure but i may change the fuel filter 2moro, I put in 98 octane the other day for the first time in ages, may have clogged it up. Only other thing is the CAS might be giving me spark and fuel pulse at the wrong time? A little stumpped...

[GTP 85]

Dont VP's have that immobiliser that you have to press the remote? well mine did anyway... have u tried disabling the immobiliser (small key in the slot in the passenger front door). Long shot but

[agrsv8]

no immobiliser, it's a VN with a VP engine

[SweetWagon]

Should be able to feel if the flexible fuel lines in the engine bay go hard after the pump primes. CAS will generally cause no spark/injector pulse at all as there is no reference that the motor is turning, also make sure you triple check your fuses and fusible links and leads are on correctly etc. ecu's are cheap could try another one

[agrsv8]

checked the fuel lines, go hard for sure, put the multi meter on injector harness pins, they are getting voltage/pulse, i've swapped around the realys with the horn and headlight relays as they are all the same and when swapped work as advertised, i've triple checked the leads, i'll prob try an ecu. It's a hell weird fault, maybe when it started running on 4/5 cylinder due to the ignition unit dying it sent stray voltage to the ecu and killed that too.

ps cheers, for the responses

[Warranty Void]

Maybe timing is out? CAS?

[agrsv8]

yeah, first I'll try another ecu (easy), if that doesn't work I'll cannibalize a CAS from the old engine if that doesn't work i'll get rather frustrated }

[GTP 85]

opps. should have realised

[NOT 38]

hey mate ive got the exact same problem. i did a full hidden wiring job on mine moved the fusebox behind the dash and relocated the battery to the boot. went to fire it up for the first time and couldnt start it. its getting fuel, spark, has injector pulse. all fuses and relays are ok. . it sounds like the timing is out because it kicks every now and then when im cranking it over and backfires through the manifold. the only thing i can think of is ive wired the cas plug or dfi module wrong?? im stumped. ! please let me know how u go!

[m62vpute]

I know it sounds stupid but could you have possibly put the leads on the wrong way around?

[agrsv8]

NOT 38- will let you know, i have that cranking and back fire sometimes too. I'm buying the ecu 2moro and i'll try the CAS too


m62vpute- I'm an aircraft technician, if i have the leads on wrong I'll buy FALCON ;P

[agrsv8]

OK, CAS has been changed, still nothing, just turns over with no sign of life, I'll definitely get another ECU 2moro, if that doesn't fix it I'll throw the old DFI and coilpacks back in, maybe i got a dud??

[NOT 38]

nar leads are all good. triple checked :P

[NOT 38]

OK, CAS has been changed, still nothing, just turns over with no sign of life, I'll definitely get another ECU 2moro, if that doesn't fix it I'll throw the old DFI and coilpacks back in, maybe i got a dud??

hey just quick question. what did u do when u changed the oxy sensor?

[agrsv8]

OK, so i put in another ecu, nothing, went and got another set of coil packs and DFI, nothing, tried another set of leads, nothing, pulled the fuel rail out and tried to start it and all the injectors squirted away like a fountain, nothing, tried it with the oxy sensor disconnected, same. Put in a new fuel filter too, nothing

It just sits there turning and turning without a glimpse of life, one splat every 20 rpm maybe

So I have no idea, I've tried every thing, i really don't think 6 spark plugs die at once, that's the only thing left. I may have to call out a mechanic, for the first time...ever....

NOT 38- I just un-plugged the old one, jacked up the car, ripped the old one out, cut the plug of the old one, soldered it to the old loom installed it and reconnected, piece of piss to do.

[agrsv8]

PROBLEM SOLVED......

2 faults in 1

OK, so here is:

I originally had an oxy sensor failure, fixed that, on the next start i guessed coilpack failure, i then checked for adequate spark, i saw plenty of spark on the plugs except for 2 on different coils, me thinking the oxy sensor may have caused it (don't know how or why) , i unplugged the oxy sensor and ran the car for like 10 secs...unknowingly coating the spark plugs in carbon down the inner ceramic (fark all but enough to earth them out), upon replacing the coil pack and DFI the sparkplugs were now earthing out down the carbon which i didn't know as i had seen spark before, After all the BS i've done i have now replaced all the spark plugs and gaped them, and what do you know, brooom, burble burble brap, burble. music to my ears.

All in all a few days of hardcore troubleshooting, but rewarding, on the bright side I've got a shed full of serv spares now! (PM me if you need any haha)

As Willie Nelson would say I'm "On the Road Again"

Cheers, to everyone for your input, Hopefully this saves someone out there a bit of work.

David

[ucwepn]

Good stuff that was a tricky one!!

[NOT 38]

PROBLEM SOLVED......

2 faults in 1

OK, so here is:

I originally had an oxy sensor failure, fixed that, on the next start i guessed coilpack failure, i then checked for adequate spark, i saw plenty of spark on the plugs except for 2 on different coils, me thinking the oxy sensor may have caused it (don't know how or why) , i unplugged the oxy sensor and ran the car for like 10 secs...unknowingly coating the spark plugs in carbon down the inner ceramic (fark all but enough to earth them out), upon replacing the coil pack and DFI the sparkplugs were now earthing out down the carbon which i didn't know as i had seen spark before, After all the BS i've done i have now replaced all the spark plugs and gaped them, and what do you know, brooom, burble burble brap, burble. music to my ears.

All in all a few days of hardcore troubleshooting, but rewarding, on the bright side I've got a shed full of serv spares now! (PM me if you need any haha)

As Willie Nelson would say I'm "On the Road Again"

Cheers, to everyone for your input, Hopefully this saves someone out there a bit of work.

David

shit aye ive never ever heard of that before. do you possibly think i might have done the same, i tried swapping my two wires over on the oxy sensor( not a genuine sensor so dont know what is pos and neg)? would cranking it over with the wires on backwards stuff the plugs ?

[agrsv8]

hey,

yeah it is very possible,

photobucket is down atm so i can't put up a pic of the spark plugs, but trust me, it is a tiny amount of carbon, but that was enough to stop it starting.

sort out the oxy sensor then throw in a new set of plugs, all up that'll be around $65-$75, cheaper than my experience in the last few days :P

[NOT 38]

hey,

yeah it is very possible,

photobucket is down atm so i can't put up a pic of the spark plugs, but trust me, it is a tiny amount of carbon, but that was enough to stop it starting.

sort out the oxy sensor then throw in a new set of plugs, all up that'll be around $65-$75, cheaper than my experience in the last few days :P

yeah not cool i have a full set of irridium tips in atm. i went through the whole wiring loom today before i seen u had fixed the problem lol. I rang ACA this arvo and it turns out i did have the 02 sensor wired back to front. so hopefully it is the plugs.

[NOT 38]

I FIXED THE PROBLEM!!!. turns out i had exactly the same problem as you agrsv8!. my dear as #### irridium tip plugs were rooted after wiring the 02 sensor back to front. bought some cheap ngk's and BOOM. it started.

[agrsv8]

Nice mate, great news

[SweetWagon]

You guys are lucky, I extended the wiring going to my CAS incorrectly during a conversion.. that took so long to work out lol