Sometimes runs sometimes doesn't

BRUCEJ455

MEMBER
1995 FORD WINDSTAR
210,000 MILES

25# fuel press. Changed pump filter & strainer. Before putting tank back up tried with tank on grnd. Statted and ran fine s(7 or 8 times ). Put tak back up. Same thing does run unles sprayed with either. Lowered tank ck'd for kinked hose or bad wires. Made good grd ck'd for bat+. Bat+ for 1 sec. Question? How does ford supply power to pump on crank & run and how do I ck without sofisticated equipt?

1 Reply

KHLOW2008

MECHANIC
41,814 POSTS

FUEL CONTROL

Fuel Injectors

The PCM controls fuel injector ON time to meter fuel quantity into intake ports. The PCM receives inputs from engine sensors to compute fuel flow necessary to maintain correct air/fuel ratio throughout entire engine operating range. Injector ON time pulse width is the only controlled variable in fuel delivery system.

Each cylinder has a solenoid-operated injector that sprays fuel toward the back of each intake valve. Fuel injector nozzles are solenoid-operated valves, which meter and atomize fuel delivered to engine. Each injector receives battery voltage through an ignition switch circuit. The PCM-controlled ground circuit is used to complete the circuit and energize the injector.

Injector bodies consist of solenoid-actuated pintle and needle valve assembly. Injector flow orifice is fixed and fuel pressure at injector tip is constant. Fuel flow to engine is regulated according to length of time solenoid is energized. This period is known as pulse width. Atomized spray pattern is obtained by shape of pintle.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Check out above link.