Seriously doing my head in....Can alternator cause misfire?

Almost not variation. If your not revving it, it just sitting constant.

 

What about fuel pressure? Would low fuel pressure produce these symptoms?

 

I've just gone and purchased some bits and pieces to allow me to install a fuel pressure gauge. I assume the best place to put this is between the FPR and the injectors? Once installed what should I expect to see as normal? Fuel pressure should be 38psi right? Is this constant or do I expect some variation at start up?

 

something for

you here briz on fuel pressure.


http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=922678&forum=technical&dtSearch=1

 

That's great beaver, thank you very much I'll definitely follow that article. It's much better than working blind. If there was a "thank you" button I'd use it .

Just as a side note, I see that he's installed the pressure gauge before the FPR and not after (between FPR and rail)? Wouldn't the test be more accurate post FPR?

 

do you have ecu talk/consult?

 

Where he

has it is good enough, I've argued that where you say (between the rail and reg) is better, but i'm sick of being shot at, ashes way works, thats all I know.

 

Just put then gauge between the filter and the rubber pipe that goes to the rail. It will work properly anywhere in the pressurised side. it is the SAME pressure all the way along the piping and the rail regardless of where you measure.

Don't confuse flow with pressure, They are not the same.

BTW I suggest you read the service manual. There are 2 pressures you need to test. One with the small hose from the balance tube to the reg connected and another with the hose disconnected from the reg but blocked at the balance tube. There are 2 different fuel pressures to measure and check .

 

See

bloody assassins everywhere.

 

Yes I have ECUTalk in the car.

 

:rofl:

He's right though, anywhere after the fuel pump but before the reg is the same pressure.

The flow will drop as you go past each injector (each one takes a volume per given time period therefore by definition you consume/reduce flow).

 

Yes

we know he's right, and no one is confused about the difference between flow rate and pressure, but i say hook up 2 gauges and you will find there is less pressure at the end of the line before the reg. Some one do it ffs.

 

I recommend replacing the TPS, I just fixed a similar issue with mine. Sometimes under light loads engine was being flooded to the point of being undriveable - all other times it would be fine.

Voltages appeared fine in EcuTalk normally. But when the problem occurred TPS reading was all over the place.

 

I wasn't having a go. Just elaborating a little. Hopefully it will go into archive and we won't have to answer it again.

 

I've been watching the TPS voltage quiet carefully and it looks pretty rock solid. Sits on 0.44 at idle (even when misfiring) and seems to climb up and down as expected with throttle action.

 

What Injectors do you have? Stock or Aftermarket? and is it a old or new wiring Harness?

My VG is now missing constently now because of number 6 giving 45psi

 

Just stock injectors running stock boost. Wiring harness is old but connectors have been replaced.

 

do you have a multimeter? go through and check that everything is receiving the correct signal??

also have you had a look at you cas? it can get dust in it and cause a shitty running motor. It seems BANG related so to me that means spark/fuel. see if you can put another cas in.

 

I've swapped out the CAS for another one with no change. I agree, I thin kit is spark/fuel related. The first time I felt it when I was driving I looked straight at my fuel gauge because if felt like I was running out of fuel. I was pushing the pedal and it just couldn't build revs. I found if I clutched it and revved it up she would start to bite again.

On your other point I've checked the injectors with a multimeter and all look fine. Also listen to them using a long screw driver and they sound like they are operating properly.