Thread: HELP! 3.9 running issues, ideas?

Originally Posted by AndyB

HI all, my 96 is killing me, and my bank balance........

It started as hunting idle, chewing fuel, lacking power, and hesitating to the point of the car shuddering at speeds over 60klm, but, not everytime its running. Sometimes it will be idling rough, and i'd stop it and restart it would seem better.

Its had visits to the landrover mechanic. So far its had installed a brand new LR MAF, mixtures all reset, new stepper motor, new radiator and just had all new Scorcher HEI ignition and coil fitted today @ performance ignitions. New plugs, leads, fuel filter. Air Filter is about 6 months old.

And yet its still playing up!! idle seems better, not hunting much at all, but does tend to dip under idle speed then come up and settle. But at cruise it is still playing up. You set off and get it up to speed anywhere between 80-100 and it shudders, the engine, enough to make the car shake, back of the speed and the throttle and it'll settle down again for a while.

Mechanic said there were no fualt codes showing at all, mixtures were re set by him this morning prior to going to get the scorcher system fitted (Lamda 1 settings...?). The machanic even took it for a drive with me and of course, it didnt play up.

What would cause the shuddering at cruise speeds???? It feels like missing or I thought maybe fuel starvation? I dont think think it should be missing now with the new ignition system just fitted.

I'm wondering about fuel pump / fuel pressure regulator. Would either cause these symptoms?

I stopped in at a LR wrecker in thomastown on my way home just to throw some more money away and picked up another pump unit and regulator. Figured it cant hurt anymore.

Does anyone think I'm on the right track? I dont know what else to do but replace every bloody part.....aarrgghh.

Its totally stock vehicle and only done 140k, which isnt much, so I'd love to hang onto it, any advice would be fantastic, cheers

AndyB..... One of my adventures to the mechanic was caused by low fuel pressure, on accelerating the pressure would not hold , simple pressure gauge connected to the inj/fuel rail at the valve test point. As soon as motor started to rev it would seem to start running on 5 cylinders and down went the pressure, replaced the fuel pump in the tank and all was sweet for a while, until the next problem. IF you scroll down to bottom of page and use the search AULRO link there's alot of info you might find useful....... good luck

Shepherd