c20xe runnig lumpy?

[belly257]

as above runs ok on tickover apart from runs to hight about 1500rpm? then u put your foot down and starts to miss higer up the rev range? anyone help?:confused: thanks

[belly257]

also is abit hard to start lol

[meritlover]

Afm ?

[belly257]

afm seems to be ok, disconnect it and it runs very lumpy its funny i think it could be the fuel pump is not high pressure enough as im running a spi tank

[Adam]

Spi tank and pump? The tanks not an issue, but if your using a spi pump, thats no doubt your mis firing problem.

[chimp007_uk]

i have a mpi gte tank for sale lol

fuel pressure, or fuelling...

[chimp007_uk]

or craig's favorite, the elusive dodgy earth

[belly257]

ive put a bigget astra mpi pump in the tank it runs well at low revs apart from it ticks over at 1500rpm just at top end revs when i press the throttle hard it starts to missfire :confused:

[craig green]

Have you examined the dizzy cap, arm & plugs?

[meritlover]

map sensor disconnected? ( however i dont think the C20XE) has one. could be a manifold leak and the engine is breathing air that is bypassing the AFM and is causing a lean run condition!!!!!

[belly257]

could do with a dizzy cap but thats in ok condition will get one tommorow just in case, will also get a bigger fuel pump, does any one know whath else pumps fit in the top of nova spi tanks? 6 10mm bolts hold them in? vectra 2.0?

[belly257]

got a new dizzy cap and rotor arm stopped doing it for abit and its started again, very annoying its like its either under fueling or over fueling :mad:

[andy_srt40]

have you checked the leads, fitted new plugs and filled it with some fresh fuel and some redex? could be an old injector not flowing enough at high revs

[Philsutton]

my money is on a airleak, if your running a mpi pump in a spi tank then thats correct fueling wise, doesnt matter what tank it is if its internal.