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VZ EVAP Purge Hose and Solenoid

Bardy-II

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Hey everyone, so after months of painful diagnostics I still haven't been able to source the misfiring problem on my VZ, after pretty much rebuilding the top half of the motor there's only a few plausible causes left and I was wondering if this would be one of them? Also curious that the last tank it had was E10, could that cause a bank to misfire?

The EVAP purge solenoid used to tick consistently, like all of the time, it no longer does and I'm just wondering could this be causing the fuel/air ratio to throw off and cause the misfire? Going to run a cheap hose over from the solenoid to the throttle body tomorrow just to eliminate the actual hose but was wondering if the solenoid could be causing problems with real shaky, rough idle and spark knocks on start up and idle?

It's been months I just wanna be able to drive my car again and unfortunately I don't make nearly enough to get it continuously diagnosed at the mechanics, and everything they've suggested so far has been the standard sparks, coils, timing chains, clean this clean that, sensors which are all brand new with the exception of the timing chains (the problem literally started out of nowhere like no rattle beforehand so I highly doubt that that would be the issue). :(
 

Dylan kingswood

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I ruined 2 injectors and a lift pump on that **** in my ftruck never used it in my life and filled the tank and got through about ten litres when it happened converted to carny and still ran like a bucket of **** until I drained and refilled with 91 jfyi I tried advancing and retarding dizzy and played with everything else and nothing but running 91 again fixed it
 

Bardy-II

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I ruined 2 injectors and a lift pump on that **** in my ftruck never used it in my life and filled the tank and got through about ten litres when it happened converted to carny and still ran like a bucket of **** until I drained and refilled with 91 jfyi I tried advancing and retarding dizzy and played with everything else and nothing but running 91 again fixed it

Yeah okay sweet maybe i'll go down and chuck a tank of premium in just to rule it out! Yeah it's **** stuff but it says E10 compatible so I thought yea why not she'll be reet but she's not :')
 

DavesSV6Tonner

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Is this misfire only at idle or is the engine down one cylinder throughout the rev range?
Did you get an 'evap emissions' fault code?
 

Fu Manchu

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There was a slight improvement in the idle when I replaced mine.

Have you done something as simple as change the fuel filter? Takes a few minutes on a sedan and is cheap to do. Might help eliminate a possible fuel restriction?
 

Bardy-II

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Is this misfire only at idle or is the engine down one cylinder throughout the rev range?
Did you get an 'evap emissions' fault code?
Hey man have been away thanks for the response! The misfire is constant on 2,4 and 6, the rpm counter fluctuates at idle which makes me think it's a vaccum problem on that bank, so far have replaced sparks, switched coils bank to bank, switched injectors bank to bank, replaced manifold gaskets, replaced MAF, replaced lower manifold, replaced cat on that side, replaced o2s on that side, no change in performance still sounds like a tractor. I feel like it went a bit too suddenly to be timing chains considering I literally drove it that morning there was no pre-existing timing chain noise or fault until I started it up a couple of hours after driving it?
 

Bardy-II

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There was a slight improvement in the idle when I replaced mine.

Have you done something as simple as change the fuel filter? Takes a few minutes on a sedan and is cheap to do. Might help eliminate a possible fuel restriction?
Hi Fu yeah car is all up to date did a major on it just after buying it, fuel filter, oil the whole lot. If it was a fuel restriction its more likely that it would effect both banks though?
 

greenacc

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CAM sensor problem on that side?
Could try swapping them side to side.
 

Bardy-II

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CAM sensor problem on that side?
Could try swapping them side to side.

Yeah I think that's gonna be the next try, if not then i'll have to have a closer look at the chains. If you pull the rocker cover off can you generally tell if the chains are stretched or not really? Like is the play noticeable?
 

greenacc

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Doubt you can see the play that easy, but pulling off the rocker cover should still be worthwhile to check for excessive sludge and **** build up. If you find out your engine looks like a swamp inside well you know you've got bigger issues than just a misfire. Check the PCV hole is clear while you are in there. It's a good idea, but Im too scared to do that to mine cos luckily it runs perfectly and I don't want to start trouble LoL!
Have you had a good look and clean up of all the earth wires and MAF plug and all the little things that might have been overlooked so far?? ;)
Sometimes the MAF plug and other terminal get a green corrosion growing in the plug which is very hard to see...
 
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