Bad misfire?

[sgould]

I went down to Swedish Day, and back today.  140 miles each way.  Half way down I used full throttle to clear the way for traffic entering te dual carriageway, and the engine gave two big "hiccups" before continuing normally.  I found that I could get the engine to repeat this on the rest of the trip about 50% of the time when hitting full throttle.  No engine light.  Otherwise ran normally.  I will be looking at varios readings tomorrow.  But any thoughts?  DI unit?  It's only three months old and one of the new design.  But I would have thought a P13** code.   Fuel pump?  Not sure, but after the first hiccups it accelerated OK even when keeping my foot on the floor.  

I'll look for pending codes etc. tomorrow.

[carrera]

Hmmm

See what codes you have, does it seem like plug fouling, which would be strange if the car is up to temperature & being driven normally.

Is boost / MAir behaving as expected & achieving expected values

[Audax]

My brother has apparently got through 3 of the new design DI units in less than 2 years... he did mention something about no codes or the wrong codes being generated for DI failure.

[carrera]

My Dame Edna has been running on a DI cartridge which occasionally generates the usual 1312 / 1334 DTC's when the car starts in wasted spark mode & hot for about 6 years. Sometimes the CEL even clears itself.

Might be worth putting the old DI back on for diagnostic purposes, at least

[sgould]

May not get much done today.  It's raining...

[sgould]

When the rain stopped briefly, I went down and plugged in the Tech2.  No codes.

I did find this for knock and misfires, but I don't know over what period it was recorded.  I then went for a drive and there were no symptoms of any problem.

 



I tried the DI check, but it kept refusing due to "low coolant temperature".  The coolant was mid eighties and the gauge on the dash was horizontal.

[carrera]

My understanding, which may be wrong, is that those knock counts and misfires are only cumulative for the current session. Certainly the misfire counter. Wat happens if you pull the fuse, will that perhaps reset the counter as well as the learning. I would get the reset done, then go for a drive & have someone else watching the Tech 2 data as you drive

I note that the knock counter and misfire count are both higher on cylinder 1, though WIS does comment that knock control is a normal function of the engine management system 

[sgould]

The same screen as before but after a quick 12 mile loop, including one section of the M1. No problems with the engine, no hiccups, nothing.

[carrera]

Instructions on two methods to reset the counters here... https://www.trionictuning.com/forum/viewtopic.php?t=5974

Maybe just a slug of poor quality fuel / contamination ?

[sgould]

I'll have a look this evening.  In London (by train) today.