What is the life expectancy of injectors before fuel economy is affected? I have gotten a range of answers from different sources such as( not neccessary to replace,just clean) to definitley replace after 80,000 to 100,000 miles . I have a 91 astrovan 4.3 L ENGINE with throttle body.Injectors never changed. It has304,000 miles runs good except may occassionally stall when stuck in traffic during summer/spring but starts right up again.
An easy way to check the injectors spray pattern on a throttle body is with a timing light.
Hook up the timing light and start the engine. Point the timing light at the injector noozles. The timing light will have a strobe effect where if there are any droplets of gas coming out of the injectors it will be seen. If all that is seen is a clean cone spray pattern there’s nothing wrong with the injectors.
sounds logical and a great idea thanks