Rough as guts!

[89berlina]

Hey guys,

Well here is the scenario. Car wasnt starting and stalling awhile back and began running rough suddenly. Leads, IAC valve, spark plugs have all been checked, double checked and changed but the VN is still running incredibly rough. Also checked kickdown cable and its fine. When I changed the leads over, that seemed to have made it better (not stalling anymore), but still sounds like it missing on a cylinder or something. Took for a test drive and it has absolutely no power when you floor it either. If anyone got any ideas, I really need your help. I'll try give you as much helpful information as I can.

Well firstly the fuel pump had been whining quite abit before all this happened. I know the pumps normally buzz away but mine was whining really loud! The pump was replaced when I bought the car and it was running on very low fuel supply. Could this possibly be the problem??? Will check the fuel system pressure but just wanting some prior knowledge so I can source out whats wrong. It doesnt stall at the moment but it idles real bad like it has a hot cam if that makes sense to someone. Im thinking that it may be a fuel issue. Checked injectors resistance as well and it was all good. Its when you accelerate it seems to be really rough. Lack of fuel pressure maybe?

Any help would really be appreciated.
Cheers, Rhyan

[88GreenVN]

Maybe worth checking the coils with some know good ones.

Are you getting good spark - like if you hold the lead just away from the plug - do you get a nice strong blue spark jumping across to the plug.

Use well insulated pliers.

[89berlina]

Maybe worth checking the coils with some know good ones.

Are you getting good spark - like if you hold the lead just away from the plug - do you get a nice strong blue spark jumping across to the plug.

Use well insulated pliers.

Yes spark is pefect. Took all the plugs out and cranked the motor and got a nice blue spark. All plugs are burning really well and tested the coil pack and its perfect. Lost for ideas...

[88GreenVN]

You do have the leds in the correct firing order yes - can make them run like a bag of pooh if they are mixed up.

[89berlina]

You do have the leds in the correct firing order yes - can make them run like a bag of pooh if they are mixed up.

Yeah, ignition side of things is all good - trust me. Double checked, tripled checked and so on. Its definitely sparking and leads are in order

[VrWagz1]

If your confident of all that then check the fuel pressure and go from there. How many k's on it. Not a compression issue.

[89berlina]

If your confident of all that then check the fuel pressure and go from there. How many k's on it. Not a compression issue.

It has around 250,000 on the odometer. All plugs however are burning a nice tan colour, which seems a good indication of good compression. Also checked the cylinders when changing the main bearings and conrod bearings for compression and there fine.

[88GreenVN]

Have you run injector cleaner through it at some time? Possibly fuel related.

[89berlina]

Have you run injector cleaner through it at some time? Possibly fuel related.

Yeah its fuel related... well sorry "it was" fuel related. Itsall good now And I mean its running beautifully! Removed the fuel tank and was horrifed to find fuel that looked the colour of coffee. Flushed the tank out a few times with 20 litres of thinners and replaced the fuel filter which was pretty much brand new but clogged with rust and sludge.

Then ran down to the servo and got myself some premium unleaded and filled the tank with 15 litres. After I got it started I was disappointed at the time because it still ran rough. I then drove down to the servo and added injector cleaner and filled the tank full with premium. Took it for some good 100 kilometre runs and all of a sudden I have 6 cylinders again!!!

[88GreenVN]

Now that a horrible thing to find coffee coloured fuel. Bet that was a suprise to you

Car is probably so thankful for you taking the tank out to have a look inside.

Good job