Thread: Missing under load.

Apart from the obvious like old spark plugs, old rotor, old plug leads, the next most common ailment is sticking exhaust valves.

So I suggest that maybe you replace plugs, leads , rotor and maybe cap if they have not been done for a long time.This is pretty cheap.

If it still does it after that then its most likely to be sticking exhaust valves which requires a top overhaul.
Regards Philip A

Only replace the rotor and cap with genuine lucas items and get good quality leads. Non-genuine rotor buttons are notorious for not working after a few hundred k's or not at all.

Plenty of posts on recommended leads but I find the Bosch ones easy to obtain and have been great so far.

can anyone help me what could i do to my disco 1 3.5 motor to put more go to it?

Originally Posted by Disco Rob

Hi guys,

Lately my '98 disco has developed a miss when it starts to get under load, but it's more when climbing a hill, but if on a flat road it's fine, except just after climbing over a hill, it'll still miss for a little while, but then returns to normal. It looses alot of power, and the whole car shudders at times. It's a 3.9 V8, and i'm after some input for possible reasons for it.

Possibly a blocked fuel filter, tired fuel pump or blocked fuel pump strainer. The pump can be replaced with a Bosch BFP772 aftermarket pump suit Commodores.

Originally Posted by v8dunekiller

can anyone help me what could i do to my disco 1 3.5 motor to put more go to it?

New cam, hi comp pistons, tune up, head port, new exhaust, or drop in a 4.6 motor.

Originally Posted by bee utey

Possibly a blocked fuel filter, tired fuel pump or blocked fuel pump strainer. The pump can be replaced with a Bosch BFP772 aftermarket pump suit Commodores.

Beat me to it Bee Utey.

Just give it a good service. New fuel filter, plugs, leads and dizzy cap and rotor. If its still doing it check the fuel pump.

Matt

yeah thought about putting stage 2 heads on and new cam and lifters but dont know would it be worth it doing it to the 3.5 or just putting the 4.6 in im still trying to get a price but it seems no one in perth gets back to me?

Originally Posted by v8dunekiller

yeah thought about putting stage 2 heads on and new cam and lifters but dont know would it be worth it doing it to the 3.5 or just putting the 4.6 in im still trying to get a price but it seems no one in perth gets back to me?

A cam and hi comp pistons will get you a free revving motor for $1K to $2K that won't easily drop a cylinder liner. Find a set of used 3500S pistons, same bore size. You can even do it in the vehicle if the bottom end is OK, whereas a 4.6 top hat linered motor will set you back lots more.