down on power up on fuel.

[rigga]

gday all, looking for some advice on were to go next on my nav, its a 03 zd30 that has clocked up 300,000kms and has lost some power and using a fair bit more fuel. i used to get bout 550kms out of a tank driving to work and back and now i am down to bout 450-500 if im lucky. i checked the valve clearances the other day and 9 of them were out of spec so had to pull them out, unlucky for me my model has the valve lifters and shims as one unit and they cant be ground off at 80 bucks a pop for new ones i said f#@k that and swapped them over with some out of a 2002 spare motor i have that has the shims and lifters seperate, i got some of them ground and off i went, while i was there i got me injectors checked and the were stufffed to, 4 new injectors at $160 each 4 new glow plugs and this simple valve clearance check was adding up. so i put her all back together and was expecting her to scream along and get me economy back, but its no bloody different. so now im stuck, was thinking maybe the cat could be blocked or something, has this happend to anyone? ill prob stick a 3inch system on later in the week to see if it helps but if anyone else has any other ideas would be much appreciated. cheers marcus

 

[Old.Tony]

It could be as simple as the servo is now using a slightly different grade of fuel, too.

But you could try something to your car first - no damage with this procedure, it just forces the car to learn the fuel mapping again. At its worst, it will do nothing. At best, it will improve your fuel economy.

1) Note down your trip meter if you use that to measure mileage per tank
2) Remove the negative (black) lead from your battery
3) Press the BRAKE pedal for a couple of seconds
4) Put the negative lead back on the battery
5) Take the vehicle for a gentle drive (without a load on it).

The worst it will do is reset your tripmeter. Hope it helps!

 

[rigga]

cheers ill give it a go

 

[tweak'e]

the ZD30's don't learn fuel mapping as such. the reset deletes the throttle postion data, ie it resets the idle position.

i would take a look at the inlet manifold. by 300,000k its probably fairly well blocked up with black sludge. probably time to pull it off (maybe even the head as well ) and clean it.

 

[Dave]

Got any sand dunes around your area ?

Go for a run and drive it hard, I reckon that will clean her out.

Mine always goes better after a hard day driving.

Dave.

 

[rigga]

inlet was all good had it all off wen i did the valves, i've had the egr blocked of for ages so its kept it cleaner inside, um dunno bout the dunes but it gets worked pretty hard most the time towing trailers and stuff.

 

[Dave]

Everytime I give my Nav a flogging she always goes better and gets the economy back to its best.

Dave.

 

[Dave]

Food for thought, has the cat collapsed ?

Dave.

 

[Krankin]

Food for thought, has the cat collapsed ?

Dave.

Well worth checking that out....

Dont know about diesel cat, but a little known fact about petrol motor cat is that there meant to be replaced about every two years.

I had mine break up and completely bock the ex sys in my XF ute, though happened slowly over time and it took me ages to work out why i was so down on power, more and more over time then it blocked up so much that the engine died while driving up the Hume on way home from work one day.

Got it home eventuly and took the cat off, engine ran fine so cat was blocked.
Poked down a length of 95mm SDI and got all the crap out , put the pipe back on and away she went, good as gold.

 

[Dave]

GU 4.8's are prone for it.

Dave.

 

[tweak'e]

i have seen pics of the diesel cats blocked up with soot. not sure if thats caused by excessive soot or blocked by heavy metals from oil etc.

 

[Dave]

Yeah I have seen pics of a GU ZD30 Cat blocked.

Dave.

 

[rigga]

yeah was wondering if that could happen, looks like a prick off a job to pull it all apart so might just wait for some funds and put a whole new system on