Technical Preprogramed throtle

[balon_sandi]

Hi all.

Here is the thing. Tipo 1.4ie and I am wondering is it normal, 1. and 2. gear in auto throtle gives to low power and car goes like cutting fuel. When I press throtle it runs fine or if I press the clutch, in IDLE also runs fine. This also apears, when I lay the foot off the throtle (when car is decelerating) in 1. or 2. gear and RPM are betwenn 1700-1000. Is it ment to go like (cut fuel) in these RPM in low gear (1. and 2.) ? Do all (gasoline) Tipos do that ?

 

[balon_sandi]

I might add this. By "cutting fuel" I ment car does not shut down, it tugs. Like it is not geting enough fuel for that rate of speed.

 

[Trancendental]

Although the Tipo is very old, it has some really advanced technology in the Engine and a lot of it is mechanical.

There are vacume senders and recievers in there which control things such as Idle Speed, Fueling and Air Mixtures.

Page 72, Chapter 3, Section 15.

The Weber TDLE type Carburettor is of fixed jet, twin-venturi sequential throttle type, with a manually-operated choke. The primary throttle valve operates alone except at high engine speeds and loads when the secondary throttle valve is operated, until at full throttle both are fully open.

This arrangement allows good fuel economy during light acceleration and cruising, but also gives maximum power at full throttle.

The secondary valve is activated mechanically. The primary throttle barrel and venturi diameters are smaller then their secondary counterparts.

The carburettor is a complicated instrument with various refinements and sub-systems added to achieve imrpoved driveability, economy and exhaust emmision levels.

.... blah blah blah ....

A Fuel cut-off valve is fitted to shut off the fuel supply during engine overrun conditions and when the ignition is switched off. A "throttle closed" switch is fitted to the throttle leaver and supplies a signal to the fuel cut-off control module on the 1.4 litre models, or the Digiplex 2 module on the 1.6 litre models. The fuel cut-off valve is operated by a solenoid allowing fuel to flow. When the throttle is closed and the engine speed drops to around 1800rpm, the solenoid is de-energised, thus cutting off the fuel supply. When the engine speed drops below 1800rpm, the solenoid is re-energised, thus restoring the fuel supply and ensuring the engine does not cut out.

This improves fuel economy and reduces exhaust gas emissions.

For further Details refer to Chapter 4.

Maybe your one is faulty or not warm enough if it pulling too much.

 

[balon_sandi]

Hi Transcendental. It is not pulling so often, only in certaing conditions. I suposose this fuel cut off valve is also installed in mine (SPI) engine ass well. Maybe it is runing fine, but sometimes when "pulling" apears, I need to rise RPM a little higer with throtle, then is stops. Is the car suposed never tu pull in low gears? Because if so, I believe that "cutt off" valve thing is a bit slow reacting. Where is it located ?

 

[Trancendental]

When you press the throttle down does it sound like the engine is not spinning as fast as it should?

Does the cut off feeling happen when the engine is warm (after being driven for 30 minutes)

If so there may low compression somewhere, it maybe a minor issue like a loose or split hose.

You may want to check the throttle cable and throttle valve, it may be sticky, blocked or dirty.

Might also be dirt and grime in the fuel lines, use some petrol treatment with each fill up for your next 5 full tank fill ups or so, see if that helps.

I have similar symptoms when I try to drive my car and it hasn't fully warmed up yet.

I don't know where the cut off valve is

Haynes Says Lack of power maybe due to:

1) Fault in the Fuel Line
2) Faulty Fuel Pump
3) Air Leak at inlet Manifold
4) Ignition system Fault
5) Faulty Choke Mechanism

 

[balon_sandi]

Haynes manual is sadly writen for tipos with mechanical Carbs. I've checked that manual. The cutoff valve is located in the Carb in tipos with manual carb. But my car is mono-jetronic and the system is not the same. But there is no lack of power as I can detect.. and speedup is normal. Also it runs good in IDLE. Duno, maybe it is doing that for a long time, I just started puting eyes on that issue. Do you have manual for mono-jetronic engines ?

 

[Trancendental]

I haven't seen a different Hayne

Maybe one of the experts can help