2.5DI fuel pump/smoke adjust

[Ransettimies]

I have bosch original pump on my 95 transit.

I adjusted main fuel screw and idle rised so there is now more fuel? "Problem" is that my car wont smoke black even i screwed more fuel.

There is smoke screw top of the pump under metal cap. Do inhave to adjust it also? Im not looking just black smoke but little bit black smoke tells me that there is some horsepower gain



So now i just think main fuel screw only rised idle but not fuel. Btw i adjusted idle back to normal with lever screw.

[Keef]

viewtopic.php?f=18&t=3968

[Ransettimies]

Thank you. Is main fuel screw adjust useless?

[gotgcoalman]

One is for more umphhh and the other is to go a bit faster with the extra unphhh you have achieved

Vroom vroom

Sent from my Plus E using Tapatalk

[Keef]

Thank you. Is main fuel screw adjust useless?

Main fuel screw only increases maximum fuel at full revs therefore top speed. The other adjustment should improve acceleration/torque

[Ransettimies]

Yeah now i feel the low end torque


Street corners can be driven easily with 3rd gear instead 2nd before

[Ransettimies]

It was fine long time ago until i turned screw more. Performance was good but fuel mileage dropped little bit.


Yesteray i tried turn it back but now it smokes even more


Is there some stock position if i turn screw counterclockwise and then clockwise some turns?

[andypdq]

Adjusting the main fuel screw shifts the whole range of fueling up or down, That's why if you turn the main fuel screw in a substantial amount, you have to re adjust idle speed. Adjusting the torque top adjusts fuel distribution characteristics within that range.

[cherniy_chack]

If you turn the screw clockwise, then the fuel supply increases, if you turn the screw counterclockwise, then the fuel supply decreases.
So they write on the Russian-language forums Ford Transit.
https://lh3.googleusercontent.com/proxy ... Kr0KQqvtTw
The hydraulic corrector piston acts on the feed regulator, limiting the maximum fuel supply.
The piston is forced by spring compression, which is set by the adjusting screw and the fuel pressure in the fuel pump housing, this pressure also controls the injection timing, pushing it forward with increasing engine speed and increasing fuel delivery at high speeds.
When the screw is turned clockwise, the compression force of the spring decreases, the feed increases.
If your motor smokes, then the propeller must be turned counterclockwise.

[Ransettimies]

Yes ive turned many times counterclockwise but still too much smoke.


Thats why i asked stock position, example , counterclockwise untill it stops and then 1.5 turns clockwise etc

[MinorMatt]

Yes ive turned many times counterclockwise but still too much smoke.


Thats why i asked stock position, example , counterclockwise untill it stops and then 1.5 turns clockwise etc

There is no "stock" position... sorry

[Ransettimies]

Damn

Will it run if screw is all way up?


Ive turned about three times counterclockwise and still black smoke comes and engine pulls like bull.


Black smoke and "performance" is not bad, just want my fue economy back

[andypdq]

Just to clear things up, The vane pump pressurises fuel in the main body of the pump, the pressure regulator, next to the fuel inlet port controls the pressure of the fuel in the pump body, relative to rpm, which affects the rate of timing advance, if you knock the pin down on the pressure regulator it increases pump pressure relative to pump speed, which increases the rate of advance.

This has little effect on total fuelling, that is controlled by the fuelling levers, throttle position and governor spring rate. All the main fuel screw does is move the control levers wholesale, which shifts fuelling range.

If you're running the pump on a turbo engine then it never will fuel ideally because for that you need a boost pressure compensator, rather than the fuel pressure regulated torque top designed for the NA engine.

[Keef]

Just a thought here and I don't even know if this is possible but if the torque sleeve sticks the syptoms are normally the opposite of the symptoms you are experiencing.
Could the torque sleeve stick at the other end of its travel thus giving great pull but smoke and poor fuel economy?

[andypdq]

Correction, if you increase internal fuel pressure by adjusting the pressure regulator with the NA torque top, you will increase fuelling and timing at any given engine speed.