Consumption double

[rparker Biofuels Forum Newbie Find all posts View Profile Close rparker]

Re: Consumption double

Guys, just did a search on Google about fuel consumption for 1KZ-TE surfs and this thread came up.

My problem is simple. I'm getting 300km from a full tank of normal diesel in my Surf. The car is stock standard, I've changed the Nozzles, cleaned up the fuel pump, returned the car's specifications all back to factory and even changed the spill valve to no avail. I'm still getting terrible economy from the truck.

The wierd thing is, there is no unburnt diesel smell, no black smoke, no idle problems, no power issues, nothing that could point to something being wrong with the vehicle.

The car is just thirsty for no apparent reason. This might be the case when you use BD, something in the ECU turns "on" and you get terrible consumption as a consequence.

I think I'm just gonna start learning to live with it, my advise is not to mess around with the thing, once your ECU decides to go "thirsty" mode it might just decide to stay there and you have no choice but to accept it even with dino diesel

[RossH Junior Member Find all posts View Profile Close RossH]

Re: Consumption double

Hi rparker

Bad news on the consumption

I need to check with you though. In the second line of your thread you say you get 300km from a tank of "normal diesel". I understand this to be petrodiesel, the stuff we pay $1.30 a litre for. If so then that's fairly scary and very expensive. When I said my consumption was double I was comparing my 700km from a tank of petrodiesel to the much lower distance covered of my biodiesel. Since then I've reinvented my BD setup and method, both now much more efficient, to produce better fuel but the consumption is still disappointing.

One of the early ideas on this thread was to do with injector timing. I've yet to get that looked at but feel it may be a reasonable idea. I'd be interested to hear what other folks have to say about your problem though. 300km on petrodiesel is a knockout.

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Consumption double

Ross, with the injector timing too far advanced the engine is actually using power to compress the expanding mixture.

Does the car seem strong with quick throttle reception at very low throttle settings, but then when going flat chat the engine seems to labour a bit? If so, then those are the symptoms of advanced ignition timing.

Did it seem to lose some of the peak torque it had with dino diesel? That too is a symptom of advanced ignition timing.

[RossH Junior Member Find all posts View Profile Close RossH]

Re: Consumption double

Hi Terry

Many thanks for the post.

Yes, the torque is definitely reduced when running BD. I can't say I've noticed whether it's better at lower or higher revs but will pay some attention today.

Is correcting this timing a simple thing? Is a mechanic with a dyno needed?

Thanks again.

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Consumption double

A simple thing on my vehicle, but I am unaware about yours. Do you have a manual on your vehicle?

[rparker Biofuels Forum Newbie Find all posts View Profile Close rparker]

Re: Consumption double

Yah my consumption is that bad, 300km for a full tank of petrodiesel and I'm not a lead foot by any measure of the word. I lead footed my 1KZ-TE surf and only got 200km on a full tank. Whatever happened to diesel economy man.

Anyway, I do notice that engine does have quite a loud diesel knock and it extremely responsive on a slight tough of the throttle, however power up high seems to be fine. Assuming that the timing now is 0 degrees (factory), what figure should I retard it too? -15?

I'll miss the sharp throttle but anything to get my consumption back to normal man

Ryan

[RossH Junior Member Find all posts View Profile Close RossH]

Re: Consumption double

Ryan, I don't particularly understand what the setting should be for the timing but this Thursday I've got the Hilux booked in with a diesel mechanic that will be able to measure what it is and then adjust accordingly (if necessary).

I mentioned the biodiesel consumption issue and the idea that injector timing may be the cause and he asked what it should be instead of factory setting. I'm assuming it should be a little retarded though I'd like to know for sure before the visit in a couple of days time.

Terry, I was hoping you may confirm this for me. I don't yet have a book for the Hilux though I have looked for one and know they're available for about $60. Probably a good investment.

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Consumption double

Ryan, with the extra knocking and the chrisp throttle response, it does sound like the engine timing is advanced. If the engine does a little bit better after peak torque as it is winding out, that is another indication of advanced timing. What is happening is that as the cylinder charging is decreasing and the cylinder pressure rise time is increasing, the advanced timing is compensating and bringing it up to peak pressure at TDC instead of sometime afterward.

There is only about 4 degrees difference between dino and biodiesel. However, if you are already a couple of degrees advanced for dino, then with biodiesel you are right out of the ballpark and compressing expanding gases - not good for power output as it takes power to compress those gases.

If you have biodiesel in the tank, the mechanic should be able to take it for a ride and come back and adjust it. If he is simply a parts changer then you may have some problems.

I suggest marking the present position BEFORE YOUR CHANGE THE TIMING. Then move it as far as you can in the retard position and take it for a ride. Does if feel better? worse? Can you feel the power decrease at part throttle, but the engine power curve now is much 'peakier'.

Whatever, now split the difference between the two settings, reset the timing and take it for a ride. Does it feel stronger? Maybe mark that setting and then try splitting the distance between full retard and original, try it, and then splitting the distance from the mid-point and where it was originally and try that - which is better? It's tedious, but it does work. Just keep splitting the difference.

If you don't have a dyno available, this is how your are going to have to do it. The marks on the engine are only for reference in the first place. Every engine has its own machining tolerance and timing belt stretch differences. Get the timing close and then fine tune it.

If you are running petrol diesel for the test, then set the final setting just a couple of degrees too low. If you are running biodiesel, then set the final setting a few degrees too high. That way you are in the ball park for either fuel and with a mixture in the tank you're on the money.

This is the way I do it, good luck.

[RossH Junior Member Find all posts View Profile Close RossH]

Re: Consumption double

Cheers Terry. Thanks for that. I'll post back here with the outcome of the dyno test as well any power and economy changes. I expect it will be significant.