The gf's car has developed a miss in it, its got a V6 Ecotec. The problem initially came when accelerating it would bog down and eventually run clean. Then it became hard to start etc. The fuel pump is pumping fuel, i have had it out and have connected it to 12v and its pressurizing the system. The fuel filter is clean, i've hooked up a good MAF sensor and that was fine, the oil isnt milky and the coolant is perfect, although it does build up pressure very quickly.
I thought it may be the fuel flow regulator as when i pull the vac hose off it the hose is slightly wet. The car will still run with the regulator vacuum disconnected.
I've pulled the Throttle position sensor out and made sure that is working, i've checked fuses and relays and swapped them with known working relays.
It has new spark plugs in it and i have tested the coils and leads, i've reset the computer as well.
It does not show any codes, it has got a slight leak at the back of the inlet manifold but spraying any water etc around the inlet manifold while the car is running does not make it miss etc, so possibly an internal leak? It also has some smoke from the back of it if i have been reving the car, so i think this is the most likely cause.
Car doesnt blow any smoke or steam, so next on the list is dirty injectors,
any other ideas?
V6 Ecotec Miss
Started by
_Woodsy_
, Feb 16 2011 03:58 PM
44 replies to this topic
#2
_homer_
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Posted 16 February 2011 - 04:27 PM
I'll agree with the dirty injectors. They don't cost too much to get cleaned and new seals added, plus they are easy to remove.
#3
_Gunmetal LH_
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Posted 16 February 2011 - 04:49 PM
What colour smoke? Black?
If it free revs fine but craps out under load then I'd put money on your leads being the problem.
Have a look under your bonnet with the engine running in the dark and give it a rev. If your leads look like plasma-ball's then replace them.
If it free revs fine but craps out under load then I'd put money on your leads being the problem.
Have a look under your bonnet with the engine running in the dark and give it a rev. If your leads look like plasma-ball's then replace them.
#4
_Woodsy_
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Posted 16 February 2011 - 05:50 PM
The smoke was from the back of the inlet manifold, its dark. As soon as you touch the pedal it bogs down and wants to stall, but if i feed it on slowly it will be ok but wont hold constant revs for more than afew seconds
Edited by Woodsy, 16 February 2011 - 05:53 PM.
#5
_BLACK LH_
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Posted 16 February 2011 - 08:12 PM
x3 for dodgy leads very common in those engines
#6
GTR469
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Posted 16 February 2011 - 08:20 PM
Did you replace the plugs for this fault?
For what it is worth just replace the leads as they can break inside when removing from plug, then this wont lead to needing to replace the coils
For what it is worth just replace the leads as they can break inside when removing from plug, then this wont lead to needing to replace the coils
#7
_robslxhatch_
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Posted 16 February 2011 - 08:44 PM
If there is ANY moisture (ie fuel )inside the vacuum hose to the pressure regulator then that IS a problem ....rip the hose off stick it in your nose (i mean that in the nicest possible way) and if you smell fuel its stuffed .. it dumps extra fuel into the manifold causing hard starts accompanied by black smoke and generally causes the closer cylinders to be most affected. You should fix this before doing anything else.BTW you can have fuel pressure but no flow and visa versa and how did you 'test' the leads (not that i think this is your problem)..after re-reading your initial post i would like to add , fix your manifold leak , you cant expect it to run well if it can blow smoke/ suck air in/out through there.
Edited by robslxhatch, 16 February 2011 - 08:52 PM.
#8
_lx5008_
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Posted 16 February 2011 - 08:49 PM
its going to be leads or one of the coils 100%
#9
_Gunmetal LH_
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Posted 16 February 2011 - 11:46 PM
Woodsy: The smoke was from the back of the inlet manifold, its dark. As soon as you touch the pedal it bogs down and wants to stall, but if i feed it on slowly it will be ok but wont hold constant revs for more than afew seconds
Smoke from the back of the manifold seems weird.
Definitely from the inlet manifold? Not the canister purge valve (black valve thingy on the drivers side on the back with 3 or 4 hoses) or the EGR valve (passenger side)?
Also check the hose that runs from the bottom of the throttle body, through the manifold to the canister purge valve. When it comes off it causes a slight miss at idle (air leak that the IAC valve cannot counteract) and could be making things worse? You probably won't notice the miss until you fix it.
If the ends have come off the hose- superglue them back on. Waste of money buying a new hose...
Smoke from the back of the manifold seems weird.
Definitely from the inlet manifold? Not the canister purge valve (black valve thingy on the drivers side on the back with 3 or 4 hoses) or the EGR valve (passenger side)?
Also check the hose that runs from the bottom of the throttle body, through the manifold to the canister purge valve. When it comes off it causes a slight miss at idle (air leak that the IAC valve cannot counteract) and could be making things worse? You probably won't notice the miss until you fix it.
If the ends have come off the hose- superglue them back on. Waste of money buying a new hose...
#10
_Woodsy_
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Posted 17 February 2011 - 10:16 AM
I've checked all the hoses, they are fine, no splits or anything in them.
I'll see if i can pin point the smoke to that small black box, I pulled the injector leads today as well as the ignition leads and the car got worse on every cylinder,
The gf's old man has a VR so i am going to borrow it and swap the coils and leads over as a whole and see if that makes any difference, cant swap the fuel flow reg over coz they are different i believe.
I'll see if i can pin point the smoke to that small black box, I pulled the injector leads today as well as the ignition leads and the car got worse on every cylinder,
The gf's old man has a VR so i am going to borrow it and swap the coils and leads over as a whole and see if that makes any difference, cant swap the fuel flow reg over coz they are different i believe.
Edited by Woodsy, 17 February 2011 - 10:25 AM.
#11
_Woodsy_
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Posted 17 February 2011 - 12:37 PM
Ok it is not in the igniton system, coils and leads and the plate below the coils were swapped over and problem still there, once car has warmed up the problem settles down abit but is still there.
#12
TerrA LX
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Posted 17 February 2011 - 12:57 PM
did you test the fuel system with a gauge, both running and static?
#13
_robslxhatch_
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Posted 17 February 2011 - 02:00 PM
did you test the fuel system with a gauge, both running and static?
and a flow test???
#14
_Gunmetal LH_
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Posted 17 February 2011 - 02:05 PM
Low fuel pressure? Sounds like it's starving.
Fuel reg could be the problem. Is the miss less obvious when the vac line is disconnected?
Fuel reg could be the problem. Is the miss less obvious when the vac line is disconnected?
#15
_Woodsy_
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Posted 17 February 2011 - 02:46 PM
Ok i got bored and pulled the injectors out for a look see, there was alot of shit in the fuel rail, an O-ring was missing completely too, Also the top half of the inlet manifold has a lifter in it? It was leaking oil down to number 6
#16
_Gunmetal LH_
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Posted 17 February 2011 - 06:24 PM
That's the PCV valve. They get s#!t in them and stick. Give it a damn good clean.
#17
_Woodsy_
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Posted 17 February 2011 - 08:59 PM
I'll soak it in fuel, hopefully i can get an o-ring kit tomorrow for the injectors and go from there
#18
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Posted 17 February 2011 - 09:14 PM
Standard off the shelf (out of he box) o rings work fine, vaso them prior to installation.
#19
_Woodsy_
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Posted 17 February 2011 - 10:39 PM
Ok i'll get some tomorrow, wasnt sure if normal o-rings would be ok. Hopefully this fixes the problem.
#20
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Posted 17 February 2011 - 11:13 PM
Spare parts stock them all in those tray boxes.
#21
_Woodsy_
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Posted 17 February 2011 - 11:43 PM
Yeah my local parts store has been through them for me for the bike, Would the idle air control valve have anything to do with the miss?
#22
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Posted 18 February 2011 - 12:00 AM
I know you checked the coils but that's what I usually find a miss is with the V6's... or fuel supply.
#23
_Quagmire_
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Posted 18 February 2011 - 02:49 AM
what's the throttle body look like?
#24
_Woodsy_
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Posted 18 February 2011 - 08:09 AM
Yeah i swapped the coils with known working ones terry, straight off the gf's old mans car
Throttle Body looks like a Big metal thing with a hole in it Quags lol
Throttle body looks fine, its nice and clean and the butterfly is working as it should
Throttle Body looks like a Big metal thing with a hole in it Quags lol
Throttle body looks fine, its nice and clean and the butterfly is working as it should
Edited by Woodsy, 18 February 2011 - 08:12 AM.
#25
_Quagmire_
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Posted 18 February 2011 - 03:20 PM
start it throw water on the crank angle sensor (timing cover area)
tell us all what happens
oh and not "it sprayed back up at me and i got drenched"
tell us all what happens
oh and not "it sprayed back up at me and i got drenched"
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