When I have 1/4 of tank or less, the car won't pull as it should, it doesn't want to go in high rpm, suffercates at 5000rpm.

What could be the problem? Fuel pump? fuel pressure regulator?

(It only happens when im low on fuel, when its more than 1/4 of tank, runs ok)

Sounds normal, all my 405s have done this, it's fuel starvation thanks to g force. It's worst when you take a right hand bend quickly.

Glad to hear thats normal, I thought I'll have to buy something new again



You mean because of the oil-sump thing?

No I mean the fuel tank. If I go round a fast right hand band you can see the fuel gauge go low whereas round a left bend it goes high. Maybe it's just my car.

Oh that, I don't worry much about the gauge, it happens on mine too, when I accelerate or break hard, even on a bumpy road, it never shows precisely, the gauge needle goes up and down all the time, sometimes a reserve bulb turns on too.

If I want to know the exact amount of fuel in the tank, I know that the car needs to be standing still and on a flat road.

It's all probably happening because of the fuel tank shape and position. I guess the didn't think much about situating the fuel pipe when they were making the car

its happening with me too , but i've seen videos at youtube of 405's accelerating when the fuel gauge is near empty light on and they accelerate daaaam fast, i think the problem is that the fuel tank needs cleaning and changing the fuel filter because when it comes near empty, what is left is all blacky stuff of fuel impurities which make it bad for accelerating, because few years earlier the car was fast on nearly empty tank.

^ Indeed. A good cleanout and filter change sounds like a good idea.

Also the 405's have external fuel pumps (mine does)? Could you incorporate a swirl pot without too much effort (if indeed fuel starvation is the problem)?

You definately do not want to be having fuel starvation problems as the mixture would be getting dangerously lean?

mine has an external fuel pump too which makes the zzzzzzzzzzzzzzzzz sound , well ur idea sounds good but he tank from the inside walls needs to be cleaned as well making it clean as new but ur idea is great for time and hassle prevention, also what fuel are u using by the way?? 90?? 92??

You mean octane number? I thought it was minimum 95 for the low compression (DFW) and 98 for the high compression (D6C)

woow, 95 here at egypt is expensive though, so we use 92 and sometimes 80 , 95 should give u great acceleration and 98 is superb

Here in the UK we have standard unleaded which is 95 and "super" unleaded which is 98. Though some petrol stations like shell do V-Power which is 99.
The original 1.9 Mi16s up to chassis number 70000000 did not have a knock sensor and were supposedly mapped in the days of leaded 4 star petrol which I think was 97 octane. So really for Mi16s of the UK you need super unleaded yet they seem to run ok on 95. Then in 1991 we finally got the knock sensor added to the 1.9.
I guess that's all irrelevant for you guys who had the DFW with knock and lambda sensors.

I have lambda & I guess knock sensor too. But I use 100 octane, not that it's much difference from the 95, but I like to think it's better for my car

scoop, here in Croatia, 95 octane is minimum, but on the other side, in your country fuel is much more cheaper I suppose?

well all mi16s here in egypt use 92 and rarely 95 if they will race , 92 costs 1.85 egyptian pounds per liter, the one british pound= around 8.5 egyptian pounds, and the 80 costs 90 egyptian piasters per liter which is the cheapest which i use sometimes for my 2.0 8v engine it's a dam fuel sucking engine so i punished it with 80 fuel .

I'm jealous. Ours is currently around 1.15 pounds a litre!

RON is not the be-all and end-all though. MON is better rating. Those of you overseas who have fuel rated in the 80's or low 90's may have it rated in this.

I would recommend reading the below as it's very interesting.

http://en.wikipedia.org/wiki/Octane_rating

The 4bie runs okay on 95 but I'll only be putting 98 into it now. Could also look at aviation fuel as the good old D6C is designed to work with leaded gas.

[quote name='KRISKARRERA' date='Jun 16 2010, 07:02 AM' post='15167']
I'm jealous. Ours is currently around 1.15 pounds a litre!
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OUCH!!!!!