Is this a misfire? Does it happen to anyone else?

[Legojon]

Yeah, I'm worried it may be injectors. But have read fuel pressure regulator is worth a look. And something about wear on the camshaft position sensor (I think its called LOL). But summat about it throwing the phase of the injectors out or something.

I'm kind of worried its a "characteristic" of the engine. But I owned it 1.5 years trouble free. So think I would have noticed. I'm hoping if I can log enough data and with each pass narrow it down some more I may eventually fix it.

Trub is, it appears random... but I'm confident it isn't... I'm just yet to find the pattern. But cheers, I'm pretty determined to try and fix it. I've spent every penny I have on this car and would cry to see it thrown away.

 

[Jfox]

It's worth getting it fixed in my opinion (providing its not something HUGE like a new engine etc... - but even that isnt too bad).

It does look fuel related.

You have the worst kind of fault. Intermittent!

 

[Darbo]

Wouldn't that throw up a fault code though?

 

[Legojon]

Well... I'm working on the principle that if its a sensor thats faulty... it wouldn't know it was faulty cause its just reading and reporting a value. Or somethings failing and not going far enough out of spec to throw a fault code. But for every part I investigate, I see a load of fault codes that could be thrown up for it. Its more than frustrating the car is giving me no clue. But I don't see why as if you could be in the passenger seat when it does it going down a motorway sliproad, you'd have your head between your knees bracing.

I've been to several garages and the general concensus its "its strange". I was kind of hoping for more But I figure, I'm going to log data every second the car is moving. Which is something they can't do. Hopefully the more I capture as it does it, the closer I'll get to solving it.

I've learnt enough already that I can make it do it 2-5 times a week. Whereas previously it was a couple of times a month.

 

[Legojon]

The other option I've been considering more and more:

 

[Darbo]

He's using birch though, that'll never fix it, what you want is oak.

 

[Legojon]

Well, this is tonights fun!!! Stuck rolling at 36/37mph for 15 seconds!!! The erractic accelerator position is me being thrown around inside the car... the yellow bits are me pushing the pedal harder to try and move faster. I didn't dare stamp on it because the harder I accelerate the worse the car bucks. Getting rapidly fed up of it.

 

[Jfox]

Your fuel pressure looks all over the shop

 

[Legojon]

Oh. Lol. I thought that's what it was supposed to look like. The garage can't reproduce it. But I'm getting ace at it now. They reckon it's to do with fuel pressure so asked me to send them the log next time it happens. I was disappointed when I saw the logs. But I'm now hoping they'll see the fuel pressures and know what to check next.

 

[Jfox]

Just looking at the numbers. Plot them on a graph against pedal position to see if there is any correlation.

It looks really random though.

Might just be number blind lots of decimal places is hard to see patterns with.

 

[GordieC]

If this was my car, I'd now be looking at: Fuel pressure regulator, fuel pump, HP fuel pump and HP fuel pump cam follower. I'd begin with the fuel pressure regulator and go from there.

 

[Legojon]

If this was my car, I'd now be looking at: Fuel pressure regulator, fuel pump, HP fuel pump and HP fuel pump cam follower. I'd begin with the fuel pressure regulator and go from there.

Already done the intank pump. Yes, I like the look of fuel pressure regulator next. Also, and I'm not sure I trust Torque App to spend several hundred pounds... but its showing a load of EGR errors. 0-40 run, hesitation show in orange. Then me flailing on the accelerator for a couple of seconds.

 

[Legojon]

Well, I've had quotes for EGR replacement, new set of injectors and fuel pressure regulator. Cheapest being the regulator. But also no guarantee of any of them fixing my issue. However, I'm inclined to think its not EGR or injectors. I have no rough idling, no smoke, no obvious leaks or smells.

In fact, I only seem to get the problem within the first gallon of fuel. When I fill up next, I'm going to fill it up to about 45 litres and see if its a filling up problem or indeed something when I max the fuel (I stop the first time the pump clicks). Surely an EGR or injector issue would be there every day!

I've rented a VCDs cable for the two week xmas period (I know how to treat myself). So I'll log fuel pressure / regulator % hopefully during the hesitation and then on the same run when its <45 litres and compare the two. Hopefully that will shed some light!

 

[andypower]

Change the cam follower. My old mk2 fr was doing the same. And for a couple of quid it's the cheapest option right now

 

[Legojon]

That seems my symptoms exactly. Was yours a petrol or diesel? I can't find much on cam followers for common rail diesels.

 

[andypower]

Oh right. Mine was a petrol so im not sure if they have a cam follower. You could ask for parts at sere motors. If they do one for a diese theyd know

 

[Legojon]

Hmm. Did a 100 mile motorway run yesterday. Averaged 46mpg. 6th gear 70ish all the way and no traffic (cruise control on). Does winter effect mpg that much as I'd usually average in the 60s!?

 

[Legojon]

Not sure if vcds is just making me more paranoid. Fuel level was showing as 20l. So I just put according to the pump 39l in. Vcds now shows 52l. Theoretically I should now have issues until vcds reads around 49l.