Are You Mechanically Minded...??
Submitted: Monday, Jul 30, 2007 at 20:16
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bunny huntin
Ok Guys, I need help....
I've had my VS Commodore at 7 different mechanics to diagnose a problem with the car. Been told heaps of different things and anywhere from $250 just to find the problem and $500 - $1000 to fix it - without even popping the bonnet!
So here goes.....
This is the problem:
1997 VS Commodore - dual fuel - runs fine on gas, hasn't ran on petrol for the past couple of years and now I want it fixed.
I changed the fuel pump, coz that was what was originally stuffed
Changed the fuel filter and put clean fuel in - now when you go to start it on petrol, it just turns over - no
sign of starting.
I was told it was the air flow meter, so I changed that - no difference. If you disconnect the wires on the air flow meter and flick it over to petrol it'll run for a couple of seconds. but really bad - like it's running down on a few cylinders.
Yes it's got fuel pressure - it's been checked
Been told it's not the injectors because the car should want to start - any ideas of things I can look for to see why she wont go?
Any suggestions would be greatly appreciated.
Thanks in advance,
Marc.
PS - Sorry if it's a bit off topic, but I didn't know who else to ask.
Reply By: Exploder - Monday, Jul 30, 2007 at 20:21
Monday, Jul 30, 2007 at 20:21
Mate if it hasn't run on petrol for a few years my money would be on injectors. A recon set would cost you $100 so it's worth a try.
Cheers.
AnswerID:
255112
Follow Up By: bunny huntin - Monday, Jul 30, 2007 at 20:25
Monday, Jul 30, 2007 at 20:25
yeah thats what i thought it was but the mechanics seem to think it should at least start even with a couple of stuffed injectors, they said its pretty unlikely that all 6 would be totally blocked. But it does run for a few seconds when the air flow meter is disconnected.
FollowupID:
516302
Reply By: oldpop - Monday, Jul 30, 2007 at 20:26
Monday, Jul 30, 2007 at 20:26
Hi
definently sounds like blocked injectors
try he carbon clean system it cleans injectors without removing them also inlet track and valves was sold to workshops thru petroject here in vic
regards oldpop
AnswerID:
255114
Follow Up By: bunny huntin - Monday, Jul 30, 2007 at 20:36
Monday, Jul 30, 2007 at 20:36
yeah the mechanic who told me to change the air flow meter said he could do that carbon clean for about $120. Do you know if the injectors are totally stuffed if it will clean the or is it just a waste of $120? Would I be better off getting a reco set??
FollowupID:
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Follow Up By: ross - Tuesday, Jul 31, 2007 at 10:38
Tuesday, Jul 31, 2007 at 10:38
I think the carbon clean is a bit of a con. I enquired about it once and they said it only works in conjunction with a tune up which they wanted to do also.
I would replace the injectors. Once an engine is running right it should self clean IMO
FollowupID:
516360
Reply By: TD100 - Monday, Jul 30, 2007 at 20:28
Monday, Jul 30, 2007 at 20:28
are they sure the injectors are OK?i didnt run petrol in our dual fuelled VP for 3 months and it killed 3 injectors when i ran it on unleaded again,changed them and it was OK again,i would get them replaced even with a set from the wreckers would probably be better and maybe a problem with the LPG/unleaded computer that is in piggy back with the main ECU could have a problem.cheers Paul
AnswerID:
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Reply By: oldpop - Monday, Jul 30, 2007 at 20:40
Monday, Jul 30, 2007 at 20:40
hi bunny huntin
from my experience i would say about 80% chance its a very powerfull brew they use
What state are you in
Oldpop
AnswerID:
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Follow Up By: bunny huntin - Monday, Jul 30, 2007 at 20:41
Monday, Jul 30, 2007 at 20:41
Victoria
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Reply By: Geoff (Newcastle, NSW) - Monday, Jul 30, 2007 at 22:29
Monday, Jul 30, 2007 at 22:29
Hi Marc,
I'd be looking at the injectors, reason I say this is the fact it will start and sort of run on petrol with the air flow sensor disconnected.
When the air flow sensor fails the V6 Commodore's use truck loads of petrol. That makes me think the fault mode for the ECU is the only one capable of getting barely enough fuel through for the engine to kick.
If they are that badly blocked an inline chemical clean is unlikely to make much difference simply because it'll take ages to actually get to the injectors.
Either get an exchange reconditioned set or remove yours and have them ultra sonic cleaned.
Geoff
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AnswerID:
255139
Reply By: Member - Kiwi B - Tuesday, Jul 31, 2007 at 09:35
Tuesday, Jul 31, 2007 at 09:35
Marc,
There's a possibility that some of the injectors are stuck rather than blocked and these are gunna take a bit of sorting if you can't get the cleaning fluid thru them.
Mebe they need removing and testing, which is quite an excercise, but it would be nice to verify injector hassles before forking out for a new set.
Good luck,
AnswerID:
255173
Reply By: Member - Kiwi Kia - Tuesday, Jul 31, 2007 at 09:44
Tuesday, Jul 31, 2007 at 09:44
You say you have fuel pressure, but how much ? Have you actually put a gauge on it and noted the pressure or have you just opened a union and noted the fuel spurting out ?
Modern computer management systems need to 'see' a minimum pressure before they light the fires. I have had a problem where the fuel would spurt about 2 metres but the vehicle would not start. A
AnswerID:
255175
Follow Up By: bunny huntin - Tuesday, Jul 31, 2007 at 10:13
Tuesday, Jul 31, 2007 at 10:13
hi two of the mechanics tested fuel pressure with a gauge and said it was all fine they also tested to see if the injectors were getting spark/power or pulsing what ever its called and they were
FollowupID:
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Reply By: Member - Kiwi B - Tuesday, Jul 31, 2007 at 10:48
Tuesday, Jul 31, 2007 at 10:48
Marc,
You mention that the injectors were checked for pulse. Was this an electronic check or were they checked to see if they are actually opening? When the injectors are left to dry-out the pintles can gum-up and not open. Need to be soaked in something to free them.
AnswerID:
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Follow Up By: bunny huntin - Tuesday, Jul 31, 2007 at 11:59
Tuesday, Jul 31, 2007 at 11:59
all they did was unclip the wires and clip the wires on to this little round thing and then it flashes showed them that its getting power there i guess
FollowupID:
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Reply By: Mal58 - Tuesday, Jul 31, 2007 at 12:02
Tuesday, Jul 31, 2007 at 12:02
Hi,
I don't know if the Commodore has one, but I would get the exhaust O2 sensor checked.
I know of a case where a friends series 80 LandCruiser wouldn't run on Petrol after the Gas caused a backfire and destroyed the exhaust O2 sensor.
It would start, then run rough then stall on Petrol, Ok on Gas.
Cheers,
Mal58
AnswerID:
255188