Situation Overview
Engine overheating can be caused by so many things and more often than not from a combination of many things which all contribute in various ways. The trick is to understand these ways.
Here I will cover issues both with carburettor and fuel injection. For further details on each subject please click on the links to take you to the specific additional information
Symptoms
Engine overheating linked to a weak fuel mix will be noticed in rising engine temperatures when accelerating hard for a prolonged or continual period, or with protracted hard driving such as climbing long uphill roads or steeper inclines. Such situations are further exaggerated if you are towing a caravan, trailer or anything else that will cause additional engine load.
Fuel Injection Types
The issues with EFi Engines that will cause overheating problems are quite easy to understand, especially if the engine with the problems is in a vehicle of lower weight than it was originally intended.
Take for instance a Range Rover and its fuel injection system that will have been designed/mapped for a two tonne vehicle that monitors and controls its fuel management by load feedback through the Air Mass Meter. Obviously in a lighter vehicle then this load is not recorded and the fuel map will remain extremely weak. In many cases this will lead to early and premature engine failure as well as poor engine performance.
Carburettor Types
Carburettors suffer weak mixture under load in much the same way as fuel injection, explained above However in these instances the load feedback is detected through engine manifold vacuum and various carburetor enrichment devices (depending on carburetor types) that come into play, in our opinions then the Holly 390 or 465 Carbs always needs upgraded to the Weber 500, similarly SU or Stromberg carbs may need re-jetting but if old and original are better completely replaced with new ones These subjects are covered in greater detail if you follow our links.
Remedy fuel injection types
For the 3 main fuel injection systems used by Rover the following applies Flapper type injection (3.5 type) need the Rising Rate Fuel pressure regulator, Hot Wire injection needs the Flat Rate adjustable fuel pressure regulator and Tornado or Optimax rechipping, Gems injection, requires Gems Tornado Chipping that also takes care of ignition and robust security issues to.
Remedy Carburetor types
SU and Holly Carbs are very Jet fussy and if you have these systems then will need either to consider an upgrade to the Weber Edelbrock 500 carburettor of consider rejetting other issues will be to check float bowl height as well as fuel pump pressure this is particularly important especially when under constant high demand
Benefits
A corrected appropriate EFi fuel map or carburetor upgrade will not only remedy the situation of weak or rich areas in your fuel load and cruise load areas, you can also expect improved economy, better engine torque, lower emissions, smoother idle and a longer engine life too,
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