Fuel cut out on long uphills

[ZD44TT]

Hi All,

 

took my car for a nice long run yesterday from syd to Bathurst. Was an awesome drive and a nice destination point.

 

Had a minor set back though:

On long uphill climbs the car would loose power and it felt as though it was caused by not having enough fuel being fed into the SU's. On down hill and flat roads it was fine hence I haven't picked up this probly driving around sydney.

 

As far as I know I'm running an electric fuel pump. Do the SU's have a small fuel surge chamber ? This is what I'm guessing might be wrong ........for some reason the surge chamber isn't able to keep up when I'm going up hill?

 

No idea really.........car runs hard and fine on flats and down hill..

 

 

 

 

 

 

 

 

 

Cheers,

Will.

[Rod F]

Maybe there's a problem with the floats in the fuel bowls?

Have you checked the float heights? The bowls sit to the side of each carburettor.

[ZD44TT]

I haven't checked but will do actually.

 

I've just read up on hybrid that this is a common prob and is most likely float related.

[Toecutter]

Will, how did you get on the track? Is it open to the public?

[ZD44TT]

yup public road.........there are ppls mail boxes along the track as ppls drive ways are connected to the track...........hahhahaha.

 

 

[ZD44TT]

i just took the float lids off and had a look just then

 

There doesn't seem to be any way to adjust the plastic floats. They seems to just pivot from the side hinge.

 

hahahah fark..........

[ZD44TT]

can anyone tell from these pics if I'm missing a mechanical fuel pump

 

 

 

[warrenz]

There is no mechanical fuel pump on your engine, the 260 had electric pump as standard. The 240 fuel pump sits at the front of the engine on the right hand side. You can measure the float setting and adjust them but people I spoke to said just buy new ones from Nissan.

 

I agree the float is the most likely problem but maybe you should check you fuel filter, is it letting enough fuel through, how long since you changed it ?

 

Are the back 3 plugs the same colour as the front 3 plugs, maybe you can narrow the fuel problem down to one carby. Maybe too late for this check as you have probably done a fair bit of flat running on the way home.

 

Warren

[JP240z]

You adjust the float heights by taking out the float, and taking out that hinge pin, and bending the metal part near the hinge, hard to explain, but it will all be obvious once you have the float out and see what keeps it at that height.

[ZD44TT]

if i want more fuel in the blow do I bend it so that the top endge of the float is closer to the underside of the float lid when turned upside down?

 

i.e recommended clearence is 13mm so should i go closer like 9mm?

 

It's very annoying.........realised there wasn't much carby oil in the carbs either.

 

hahahha car was running so nicely before.

 

I gotta get it fixed for a wakefield track day on the 20th too........doh.

 

hmmm must be the floats.......I got quoted $15 each.

[Rod F]

Now I have to think and my brain hurts  - you want the needle (that the float tab pushes against) to be open longer so more fuel flows in to the bowl, therefore you need to bend the tab away from the needle. 

[Hunter]

There is no mechanical fuel pump on your engine, the 260 had electric pump as standard. The 240 fuel pump sits at the front of the engine on the right hand side. You can measure the float setting and adjust them but people I spoke to said just buy new ones from Nissan.

 

I agree the float is the most likely problem but maybe you should check you fuel filter, is it letting enough fuel through, how long since you changed it ?

 

Are the back 3 plugs the same colour as the front 3 plugs, maybe you can narrow the fuel problem down to one carby. Maybe too late for this check as you have probably done a fair bit of flat running on the way home.

 

Warren

 

I know this is an old post but my 1974 260Z 2+2 has a mechanical fuel pump, stock standard. I think it was 1975 when our 260Z's may have changed. In my 1975 260Z 2+2 the seat belts have different mountings etc. I am guessing that one would have come with and electric fuel pump.

[ZD44TT]

just so ppl know this turned out to be a failing electric fuel pump..............new one in and she ran sweet.

 

it cut out on uphill due to not enough pressure from the pump to get the fuel to the carbs.

 

 

[stinkweed]

Hi Guys

 

We have a similar problem with our 260 - particularly at full throttle and hooning it up hills.  Just recently had the carbies serviced ( whatever that means) but me thinks maybe the fuel filters.  Don't forget to check the filter in the electric fuel pump (located next to feul tank and a bastard of a thing to get to) as this often gets forgotten. Am going to pull it out on the weekend  Buy the way we live in Bathurst and the race track is a public road all year except during race week.  Only problem is it's posted 60km and you will be booked any faster. A real cop trap.