VN series1 power break down over 3500rpm when hot

[bugadifino]

G'day all,

1st post so please be gentle, I have a strange one.

In a series 1 manual ute, once the thing gets hot & RPM gets over 3000-3500 while overtaking a car, or in a rush I can feel the power just isn't there. Its not really a misfire, though sometimes I swear it is a real slight misfire. When cold it is fine, has heaps of power.

I have replaced the DFI module & coil (second hand ebay ones, $10 for DFI, coil & leads). I'm now stumped, please help me.

[bugadifino]

no-one has any ideas?

[cruzncommo]

hmm checked your spar plugs and injectors?

[lazza44]

cat? fuel pump? cas?

[J_D]

Fuel filter. I replaced mine yesterday and it made a world of difference. The fuel in the filter was literally black, before I changed it it was harsh and breathless at the top end and sounded like it was pinging.

[vp_5ltr]

mate change your coilpacks to series 2 items and i almost garuntee the missfire will dissapear

[modcon]

Hey man, it would be worth changing your CAS as I had a similar problem at 3500rpm my car would miss and a slight surge eould occur, I changed my CAS and problem was sorted. The only hassel with changing the CAS is you have to remove the Harmonic Balancer Pully at the front of the motor, with a pully puller it easy as - hope this helps!

[CSL]

next time it breaks down get a bottle of water and pour it behind and a bit to the right of the biggest pully on the engine, on the white plug and everything attached to the white plug,
if it starts strait away it's a crank angle sensor, bout 200 bucks for a machanic to do or around 100-120 to buy the part and do yuorself

[Not_An_Abba_Fan]

Have you checked your air filter?

[IhateRICE!]

Do V8s have a CAS?

do you have the series2 coils or the series1 (looks like a Chocolate block)
coils?

[blozin]

I'd go for the CAS too they can break down when hot. The water trick mentioned above works

[bugadifino]

Thanks for all your help guys,

Its a bit hard to check the CAS when the ute is driving down the road, I can'e get it to do it in the driveway. Even by loading the motor in the driveway, it won't do it then. I have S1 coil pack, though I just bought a S2 set & DFI off of ebay for $24 including postage. I just have to try to remember if I need an adapter palte for it... or 1 of you knowledgable blokes will tell me. Lead & plugs ok, willl be changing fuel filter on W/E, that makes sence, lower fuel delivery = power brake down. The fuel pump runs for a while after the key is turned off, every time the key is turned it runs for different lengths of time, yesterday it ran for about 30 seconds, so I reckon I will have to try to replace it soon, or be stuck on side of road.

Again Thanks guys.