1990 240/DL Gas Mileage Problem

[vincent-1]

Well yesterday the car broke down, it had to be towed home. It would start, and run, but only if I gave it gas, if I take my foot off the gas, the car died. My uncle, a life long mechanic, said it could be the fuel filter. Though, I will see if I can check your suggestions to, just to make sure of everything.

[Volvofix1]

Vincent..I don't think you have a fuel filter problem,if the car had a surge between 40 to 60 mph maybe a filter. Look at the corrigated hose after the mass air flow sensor is it cracked? Next check all the hoses and vacum lines near the throttle body, the idle control motor and the flame trap. Invest in a vacum guage and test the engine vacum.It should be above 18 in. spray some carb cleaner near the intake manifold,injector bases and throttle body. How about checking the coolant temp. sensor for the computer. What color are the spark plugs , they should be a light coffee color black means too much fuel. Have you tried to check for engine codes use this web site to find out how. Listen to the injectors "click"with a 12 inch piece of steel brake line and another equal length of vacum line that will let you hold it to your ear as a makeshift listening device, also use this to listen for vacum leaks. Pull the vacum line from the fuel pressure regulator and see if it drips a little gas ,this can also make a problem. Here in our shop we use a "smoke machine "to check for vacum leaks ,but they cost $1000 good luck . Dick K. from Fla.

[Volvofix1]

Vincent..I don't think you have a fuel filter problem,if the car had a surge between 40 to 60 mph maybe a filter. Look at the corrigated hose after the mass air flow sensor is it cracked? Next check all the hoses and vacum lines near the throttle body, the idle control motor and the flame trap. Invest in a vacum guage and test the engine vacum.It should be above 18 in. spray some carb cleaner near the intake manifold,injector bases and throttle body. How about checking the coolant temp. sensor for the computer. What color are the spark plugs , they should be a light coffee color black means too much fuel. Have you tried to check for engine codes use this web site to find out how. Listen to the injectors "click"with a 12 inch piece of steel brake line and another equal length of vacum line that will let you hold it to your ear as a makeshift listening device, also use this to listen for vacum leaks. Pull the vacum line from the fuel pressure regulator and see if it drips a little gas ,this can also make a problem. Here in our shop we use a "smoke machine "to check for vacum leaks ,but they cost $1000 good luck . Dick K. from Fla.