Holding back issue

[banderson]

For the last couple of months, my car has ever so slightly been feeling like its holding back when cruising along.
For instance on a dual carriageway, it feels as though a cross wind is blowing against the car (so not a lot) but has never thrown up any other symptoms...

then the other night, I nearly ran out of fuel (not my fault, all the garages were shut and closest was 20 odd miles away) so filled up with V power, on my way home, nipped onto my private track and sat at about 75-80mph, went to put my foot down to overtake and and it bogged down badly and started popping/backfiring but as I let off, behaved smoothly, it would do this every time I put my foot down, even if I accelerate hard from a roundabout.

dropped my mate off, turned it off, on again and seems to have cleared sort of (still felt as it was originally)

theres no fault codes stored.

i removed my inlet manifold and plenum today to fit the RS inlets and noticed my red magnecore leads were covered in black marks, and the bottom off the plenum had marks too as if they have been arcing where they were touching.

i was going to try a new coilpack, but seeing this has made me think twice,

anyone have any input what could be the issue?

 

[Harbinger]

Changed plugs recently? use a circuit tester on the pack and leads before you go buying them first.

 

[MG cup]

Arcing of the leads usually goes white for reference. While the injectors are out still connected to the rail, crank the car and check for a good spray pattern (don't spray it at a hot engine )

 

[banderson]

Changed plugs recently? use a circuit tester on the pack and leads before you go buying them first.

Yeah changed plugs probably about 6 months ago, with the NGK prf6e-10 Renault recommended ones,
do you know what sort of reading I should be getting from the coilpack and magnecores?

i also fitted a genuine coilpack (second hand though but only cover 30k) at the same time as the plugs.

 

[banderson]

Arcing of the leads usually goes white for reference. While the injectors are out still connected to the rail, crank the car and check for a good spray pattern (don't spray it at a hot engine )

Haha put it all back together now as needed it for work, but it's not too hard to remove the fuel rail again lol and yeah well the black marks consisted of a white powder in the center with soot around lol

The engine was bloody hot (not overheating, just been driven for a while) when this happened.

 

[banderson]

Any other input?

 

[Billy.]

Hesitation and misfiring/backfiring on my clio was solved by replacing the coilpack and spark plugs. i had the same symptoms as you, couldn't put any power down to overtake or when exiting a roundabout/road