This'll test the fabricating skills

Well the last run out a month ago was a very short one after the plug clean-up. It hesitated a few times then but just barely noticeable, but as I said a very short run.

So... topped up the battery charge overnight and took it for a run this afternoon. Car started and ran fine on the driveway (idling fine while I pumped up the two front tyres but as soon as I got up the road the massive misfire came back with a vengence. Pulled one of the plugs, and it's not sooted up as it was last time so that rules out that it's just the plugs shorting out on the carbon - I think that was a syptom of the misfire not the cause before.

Has anyone got any ideas?

My instincts say fuelling. Runs fine on idle, and will pick up if you floor it but anything in the mid range suffers from massive misfiring and flat spots. This all happened mid-way back from the turbo change with Martin, and the only real thing to note was that the roads had a lot of standing water on them (it was a month ago when the rains started). I did wonder at the time if it was the front pick-up pump ie electrics to the fuel pump.

But open to any suggestions!

Dizzy check first I would say .Plugs re-gapped ? What boost running ?

Yep did think it might be damp in the dizzy Lee. You put on a new one though didn't you, so I wouldn't have expected it to cause a problem.

Boost isn't the cause as it's not even getting a chance to boost. Plugs at 0.6 and are clean.

[BIG_MVS]

Check the front fuel pump Darren as this can cause problems. It should be running all the time so you can have a feel/listen when on tick over at the front.

Near the drivers side front wheel arch? Been ages since I've looked under the pointy end.

No, passenger side up on the steering rack crossmember .Filter is on other side of tunnel .
If fuel pump fail though I'd expect it to conk out ..could be shit in the system .I had that with the black turbo but that would die ....

If all of the above are ok try turning your throttle/CO pot right down.


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Shouldn't be the CO pot as that really only changes idle settings.

This is fuelling or spark but odd that it will start and idle but won't go properly. Does sound a bit like the issues lee had with the blocked fuel filter. That'd be annoying as they're both quite new.

Possible crank pick up sensor.

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CO was tested and set on the pot before Darren left, and nicely below 1% as I remember, and should be no reason to change that. I guess working on the basis of what could have been disturbed in terms of wiring when the turbo was swapped, then the tdc sensor cable is a possibility as it's on that side for the air intake, so worth checking that. Also check there are no poor connections / pushed back pins on the ecu connector. Check the chip is in and home, but if it wasn't you wouldn't be running at all, but always worth eliminating positively. Check reading of the air and water temp sensors back at the ecu connector, ecu disconnected, so checking for breaks or poor connections. As this is a sudden change in running, it's either water related or something disturbed moved in the run home. It was running clean when you took it away, and had been up the road for 10 / 15 min run prior to that, so the basics are there, something has changed in a step fashion.

You haven't got a dodgey flux capacitor have you, bit like JonV's?

So if you get it up on to boost, it runs cleanly does it?

Check the vacuum lines for leaks, pressure regulator line, MAP sensor line same.

Have you checked all 6 plugs?

The wires on Will's front lifter pump fell off in my hands when I was sorting his wiring, loose connection on the pump, and the road abuse of shock vibration the small gauge wires had fatigue failed (at the crimp tag); had this hit water, I think certainly one was likely to break as they dangle down and poorly supported by the factory fit arrangement.

Just some thoughts
Martin

I don't think it's likely to be TDC sensor. They usually go when hot, and if it wasn't getting a proper reading then I don't think it would start as easily as it does. Starts on the button.

I pulled all six plugs the other day when I cleaned them up, so I can check but I don't see any issue there.

Fuel pressure reg line is a good point. It's only happening when it's trying to rev under load.

Yes it can run if you get it on boost, but it's pretty scary trying to do that when you don't know when it's going to cut the pwoer again. By the time I got home it was stalling so it can't run properly at all. But will when it's just idling. Most odd.

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Yep, the point on the plugs wasn't that they are a problem, more just to check that all cylinders are the same now, and you haven't got an odd one for what ever reason, again just to discount things. Having said that, really what you want to do is start with them known clean, run it to point of problem, run for as long as you can to colour the plugs, kill the engine and pull over. Then take them out and then look. Just a check on verifying what the fuel regulator is doing. But make sure the MAP sensor line isn't leaking too, as that will play a mock too - engine load reference input to the ecu. You have the single fuel reg setup right, forget now?

Martin

Yep. Late block but ancillaries off my old one so single reg.

Hi Darren,

Been thinking about your issues. When did you last check/change your water sensor?

To me it's displaying all the symptoms....

Water sensor is only a few months old. Plus that would show as an ECU fault with an orange light on the dash and would be no-where near as drastic as the ECU would go to a default assumed value.