Power loss under load

[Jack]

The V6 has been running a bit crap of late. It starts and idles fine, revs up to >6K, but when you're driving and put the hammer down it just seems lacking in power. Driving on ~1/4 throttle is fine, but any more than that and it feels like its running about half power. Doesn't sound like its misfiring or anything.

Changed AFM, no difference.
Changed fuel pump (as that seemed to have eaten itself), no difference
Changed coilpack, got a bit better but still feels like its down on power at full throttle.

HT leads all in good order, I'm just about to go check the spark plugs.

What else could be a problem?

[novalicous]

What sort of pump you running jack intank or external?

[General Baxter]

do you have some england flags on your car,

more drag ?

[Jack]

External, 3 bar

The old pump was a 3 bar one too, and the engine ran fine on that until recently so I'm sure its pushing enough petrol up there

[General Baxter]

jack you can now take the flags off lol

[novalicous]

i was going to say if it was an internal pump they can sumtimes not seal properly on the pipe between pump and the top mount piece

[bmw156]

hasnt got a limp mode has it?

[Royston]

Is the fuel filter blocked/restricting fuel?

[General Baxter]

hasnt got a limp mode has it?

no but something else he owns has,

im really not being helpfull here lol

[AlexW]

hasnt got a limp mode has it?

That would cause it to not rev past 3k normally.

Roystons suggestion seems the best so far if the old pump was funked.

What are the plugs saying?

[Jack]

Hmm, possibly. I'll whip that off and take a look (the last time I had a pump die it ate the input fuel hose but didn't spit anything out the output side). I did think it was getting enough fuel though as its still spitting flames out the back lol


hasnt got a limp mode has it?
AFAIK the limp mode would hard limit the revs to about 4k, yet its still going up to the redline

I did see on a quick google search that some alfa drivers have a similar problem if the cambelt jumps a tooth, but surely that would duff up the idle?

[AlexW]

Second thought, EML isnt on is it? Checked engine earths?

[Jack]

Plugs look Ok, normal colouration. One had a little oil in the gallery but nothing excessive. HT leads looked a bit worn out though, so I'll replace them as a matter of course.

I can't remember if we wired in the EML light... lol I'm not convinced it would be an ECU cutting spark thing though, as said surely it would be in some form of limp mode which it doesn't seem to be (would have thought it would cut revs around 3-4k if that was the case?)

Earths are Ok, gearbox one looks a bit shoddy but its a good connection.

[AlexW]

Does the EML come on with ign? If not, its not wired up..

I would expect that fault to bring up EML.

You say the earth is good, you tried the ole jump lead from engine to battery just to be sure.

[Jack]

Good point lol I'll see if I can find the wire and bung it on the choke light.

I did think of doing the jump lead thing, but was a bit wary about driving it with a jump lead waggling around in the engine bay - as it needs to be driven for the fault to appear

[AlexW]

Hmm good point lol Be worth changing it if you even have a slight feeling its iffy.