More C5 X7 woes - uneven running this time.

[Peter.N.]

The red one again. My son borrowed it this evening to go to Exeter, came back about 10 minutes later saying it was running rough. Power seems to be down on one cylinder although it seem to drive reasonably well. Another strange thing is that it idles at a bit over 2000 rpm, if you put your foot on the brake idle returns to normal, take it off run's fast again.

Any ideas?

Peter

[myglaren]

Vacuum leak?

[Peter.N.]

Possibly but its intermittent. sometimes it corrects itself. I'm going to take it out and give it a good thrash today and see if that clears it. Its definitely down on one cylinder you can hear it in the exhaust.

Peter

[admiral51]

I'm going to take it out and give it a good thrash today and see if that clears it.

Peter

Now after all these years as a member on this forum the above is the very last sentence i would have ever thought plausible

Colin

[Hell Razor5543]

Possibly but its intermittent. sometimes it corrects itself. I'm going to take it out and give it a good thrash today and see if that clears it. Its definitely down on one cylinder you can hear it in the exhaust.

Peter

So, 0-50MPH in 6.5 (minutes) and up to 65MPH then?

[myglaren]

I saw a GS in a scrapyard with a sign in the rear window - "0 to 60 in Fifteen Minutes".

[admiral51]

Sorry Peter i just could not resist.
However have you had any luck in sorting this out.
Cannot do anything during the week but am happy to try and sort something out over the weekend if you need a Lexia session to try and get some live data etc.

Colin

[Peter.N.]

Hi Colin

Well - I took it out this afternoon and did about 15 miles in it, never missed a beat. My son did say he had difficulty starting it and it tried to die on him going up hill so I can only conclude that it was an electronic problem, although how that can cause it to miss on one cylinder I don't know. I don't understand digital electronics, I grew up with analogue and valves.

The engine light even went out after I had stopped and started it a couple of time, I went out again briefly this afternoon and it still ran perfectly. I know that if the battery voltage drops to low it does strange things to the ECU, that was why my wipers were intermittent, but they have worked perfectly since I fitted a new battery.

I might take you up on your kind offer for the other one as I have to replenish the DPF fluid and will need the light putting out.

I am going to fit an inline fuel pump when it arrives as I'm sure the starting and dying problem is fuel related so will see how that goes.

Peter

[admiral51]

Peter that is no problem when ever you are ready.
I should be off work from Good Friday till the Monday after Easter Monday so if that fits in with you i am sure i will be about, do not think i am going away in the current climate

Colin

[Peter.N.]

Thanks Colin. I haven't put the fluid in yet so it may be a week or two.

Peter