[RichR34]

Hello,

My car seems to have developed a bit of a misfire if I rev it hard in 1st or neutral. i think its a missfire anyway - what happens is at about 4-5krpm the engine pauses and sort of backfires a bit then carries on. sounds like as if you where bouncing it off the limiter but obviously its only at 5krpm.

Any ideas of things that I can check?

Will this damage the engine? If I take it easy in 1st I can rev it all the way with no missfire.

Splitfires and NGK spark plugs where added at server 2000 miles ago.

Any advice appreciated

:cheers::cheers:

 

[BIGC82]

Wat fuel u running??

 

[RichR34]

Tesco 99 actually, as V Power went to stupid prices, but I have just changed to that over the last couple of tanks. Do you think it could be that? Worth a try going back to V Power I guess, but I've heard people say Tesco 99 is alright generally?

 

[BIGC82]

Stick to V power buddy!!!!

Sounds like ur gettin Det but not too sure on that!!!

And if you kane it on the cheap stuff thats what happens!!!!!

 

[RichR34]

Fair play cheers that though never even entered my mind that it might be the change in fuel. I'll piss away this tank tomorrow then and get a fresh full tank of V Power and see if it changes anything.

Thanks matey

 

[BIGC82]

No bother buddy!!!!

Glad it helps for the few extra p that V power costs it's well worth it for the Health of your car

Cheers C

 

[Dele Z.]

i think its just where you need to get it remapped after your mods tbh, i run mine on Tesco 99 because i dont see the point of V-Power, never had a problem

 

[RichR34]

OK after going back to V power this was OK.

Now I'm finding in 3rd and 4th the engine will cut out at about 4.5Krpm (which is pretty hairy at speed as the car judders). It only does it if I have my foot planted though, if I let the revs climb easily it's fine. Is this a misfire?

it does seem to do it when its cold (nearly freezing in the past times I tried it)?

If so why does the cold air make this happen and is there anything that can be done to solve it?

If not does anyone have any other ideas based on this new information what might be going on?

 

[Bruce-m]

There's no way you should be getting DET in neutral or first, DET normally accurs in 4th - 5th first.

Sounds like something is breaking down, plug, coils, AFM etc

 

[RichR34]

Its fine in 1st and neutral now, just 3rd and 4th doing it now (4 speed box).

new plugs and splitfires 2000 miles or so ago, would of thought they'd last longer?

 

[Bruce-m]

It isn't them then, prob something like a boost or vacum leak, have a good look round your engine bay.

 

[RichR34]

I've had a good look around to the best of my ability and all hoses/pipes appear to be connected securely.

I had a theory, could the cold air be making the turbo boost slightly more to the point the engine management says "no thanks"

As under full throttle its hitting 1kg/cm in 3rd easily now. the misfire type thing happens at 5.5K

If I drive with *slightly* less throttle the boost is a bit lower and it drives fine.

I read somewhere the standard AFM wont like goiing over 0.85 bar, maybe this overboosting is maxing this out?

Is 1Kg/cm = 1 bar? I know its overboosting due to breathing mods, waiting for boost controller and FMIC going on next year - so could it be down to the cold air making it boost more for some reason?


Will drive it nicely until i can get it looked at I guess

 

[General Banter]

If the usual suspects have been ruled out do yourself a favour Rich and get it to a tuner

 

[Bruce-m]

Pop it down to RSP and get it checked, could be the AFM starting to die.