Hi rpms when starting and staying hi while riding

high idle on starting is normal as it is the same as a choke being on. When it drops back it should be around 900. However tacos in cars are not real accurate under a 1000 rpms so have it checked manually with a rev counter. Run the fault codes to check for a problem.

check the timing of the pump as pump timing if incorrect will cause engine failure . High rpms may be from the accelerator control not being assembled properly on installation or if ECM controlled the connection to the pump is not correct. Looking at ford diesel rpm specs , some fords run to 6500 rpms while others are at 4500 . As you have not stipulated the engine size or capacity ,it is hard to advise other than to go on line to googlr - type in ford max rpms for your engine and see what it is suppose to be

Does it idle normally, but only start starving of fuel under load or high revs?
If so, check the fuel filter - just a simple plastic cylinder that the fuel line runs through before going into the carburettor. Quite cheap and easy to replace.

pour liter fluid all over the machine then throw a lit match into it

If it does start ? But wont stay running , replace old gas with new, cleanout the carb. bowell , and maybe a new spark plug !

give it a good tune up,sounds like the carb are dirty

Did you leave any old fuel in it during the winter?

BUICK RENDEZVOUS IDLES UP REALLY HIGH...WITHOUT PRESSING GAS. WHAT IS THIS?

Hi thi may be a vacum leak in one of the tiny hoses or lines at the engine ,if you dont have a vacum gage you can run a simple test by gently spay some carb cleaner spray close to the lines and air hoses with the engine runing, if you notice the rpms going high there is the problem.