just quickly. well may take a while.

[Antony]

thaught i would start a new thread, as this may cause a few headaches..


and i know my cars knakered ...but...

under 3400rpm my car pulls like a train in 1-5th.
abover 3400rpm the car will pull (and accelerate) very very quickly in 1st and second.

abover 3400rpm in 3 4 5th gears though, at full throttle it has huuuge torque flat spots. and i mean massive, to the point where im having to dip the clutch at 40mph whilst accelerating and rev the engine to stop if dying.

cam timing is spot on,
oil pressure is fixed,
checked alternator,
new battery (this didnt fix the problem)
could it be ignition timing?

so my car goes (on a 0-60 sprint)
"throttle--wheelspin.....limiter,......change gear 2nd....wheelspin......limiter, change gear .....3rd.......pulls...then splutter.....flat spot.........6000rpm huuge jump in torque.....limiter, change gear, 4th........another huuuge flat spot 5th....

however, at 30mph in 5th gear if i stick me foot down. it will pull hard till about 3500rpm, then flat spots again..grr grr grr grr grr




god i hate my engine at the mo.

 

[whipit]

Can i be first to say throttle body???

 

[mike]

ecu could be damaged, ignition timing could be dodgy, throttle body

 

[Antony]

the throttle body looks to be standard item too...
hmmm

108,000+ miles on standard TB..lol

thanks guys.

 

[Retepetsir]

TB or possibly fueling? Guess you have no fuel management?

Using an Apexi S-AFC mine is mapped for +33% extra fuel at 2.5-4krpm...mapped on a dyno.

Have you got a torque readout of your dyno session?

 

[Antony]

yeah, on my blog. its got a slump in the torque curve where the AFR drops down to 11 something.
but its had a different head for 3000miles, then replaced the one that went on the dyno.

no fuel management at all.....but it wasnt as bad as this before.

 

[frank]

antony

what air filter setup have you got ?

 

[ollie240585]

Frank, IIRC it's one of the green mushroom Induction kits!

 

[Retepetsir]

Have you tried it with another filter/without a filter for a couple of minutes?

 

[frank]

ollie240585

thanks
i had a big flat spot in the mid range when on gas and tried allsorts to no avail
i ended up googling and saw on a forum a yank v8 had the same problem, someone told him to restrict the intake a bit and when i restricted my drainpipe (inserted a smaller pipe inside), it cured it !
so i,m assuming i was gulping too much air and leaning out ( my afr guage seems to back it up anyway)

 

[Antony]

hmmm, yeah i have a mushroom filter with 2 90deg silicone bends and 30cm of ally pipe.

might try that then.

or get it mapped..lol

 

[NeX]

sounds like you have been ranting it, maybe it has had its day.

check for good compression, maybe something like the piston rings or the head gaskit?

 

[Antony]

its on its 4th head gasket in a year..lol (by choice though)

the compression when tested was 110psi for all 4 cylinders


and i have another engine sat on my drive waiting to go in..