POWER ONLY SLOWLY ?

hi i have a mondial 30L qv,changed plugs and leads,now its running on all 8 (not just seven) checked compressions(between 175 190) all good, but when you floor it the noise you get is just the air filter box pulling in air but no go just noise, but if you floor it slowly you get good acceleration but only up to 4500rpm , then it just struggles, when reving engine stationary it gets up to 4500 rpm ,but then splutters as if its a ignition fault,i have cleaned all pick ups on dissy,s and rotors,i have also noticed the fuel tank is pressureized when taking the filler cap off ? not vacuuming, any guidance would be great,thanks

 

thanks guys i will check then out tomorow,since i did my circuit board,(took apart and resoldered all the lamanated sheets back together the electrics are spot on) just the engine to sort, and some suspension bushes to replace, the fuel tanks pressurizing is a bit of a worry ! its not a vacuum, its pressurizing almost blows the cap off when i unscrew it ?

 

has no one had these problems before ?

 

thanks for your input guys,no not been stored,the guyi bought it from never even new it was only running on seven pots,i would like to know if it is fuel or igniton,

 

ive found this as regaurds to the fuel cap pressurizing point,


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Mechanical Fuel Injection
As this subject is large and fairly comprehensive it has been broken into the following sections:

1 Introduction and operational overview 2 The fuel tank
3 The fuel pump 4 The fuel pump relay
5 The accumulator 6 The fuel filter
7 Systems pressure 8 The airflow sensor
9 The fuel distribution unit 10 The warm up regulator
11 The cold start injector 12 The auxiliary air valve
13 The fuel injectors 14 System overview diagram

NOTE:- whilst working on any fuel system, care and attention should be taken to avoid the petrol coming in contact with any source of ignition, this can include: hot engine components, High Tension (HT) sparks and smoking.


Introduction
This form of mechanical fuel injection has been used on the internal combustion engine for many years. Mechanical fuel injection systems first saw light of day at the turn of the century, however the following 100 years has seen the system evolve from a very basic and almost crude fuel delivery system, to the recent mass produced versions of the Bosch K and KE Jetronic. The mechanical fuel injection system has recently been overshadowed by modern electronic injection, which enables the use of lambda closed loop control. The electronically modified Bosch KE also has this capability although it never achieved the popularity of the pure mechanical system.
This following overview is a brief description of the system.


Bosch K Jetronic operational overview
The system may seem very complicated at first, but it can be broken down into specific areas and fault finding is therefore made easier.
Fuel is delivered from the fuel pump to a metering (or fuel distribution) head and depending on the engine's temperature, the correct amount of fuel is delivered via the injectors to the engine. The injectors on this system spray fuel continuously in a fine atomised spray into the inlet manifold.
Cold start and the warm-up period are also catered for by a cold start injector and a reduction in the control pressure. The idle speed is increased by the auxiliary air valve.
The fuel pump will have the ability to provide a huge amount of fuel from the tank of which 99% will be returned. Due to the nature of this system, specialised equipment may be needed.




The Fuel Tank
The fuel tank is the obvious place to start in any fuel system explanation - unlike the tanks on early carburetor fuelled engines it is a sealed unit. This allows the natural gassing of the fuel to aid delivery to the pump by slightly pressurising the tank It may be noted that when the filler cap is removed, pressure is heard to escape. Filler caps are no longer vented as previously found.