hard start/irreguler idle 89 ford - Ford Forums

700mach1 · 06-03-2008, 18:18

89 ford 3.8 liter engine
problem #1, i am having a problem starting this car, the engine cranks over several times before it will start, then it will idle irregularly for a few moments before it smooths out( it reminds me of starting a car with a carb. instead of fuel inj.). this condition happens when the car has been shut off for 5-10 min. or longer. if i turn it off and restart it , it will start immediatly, like fuel inj. should.
problem#2, if i am stopped in traffic(stop light) for several min. the car will develop an irreguler idle(approx 500-1000 rpm)until it stalls. it will restart immediatly, but the idle problem will remain until i drive at higher speeds.the check engine light does not come on.
i have replaced the fuel pump relay, fuel filter, cap, rotor, plugs, wires, IAC, air filter, MAP sensor, cleaned the throttle body, disconnected and pluged the EGR valve, and have used several cans of sea form injection cleaner in the tank. all vacumn lines are connected and appear to be in good condition.
thanks for any suggestions.

1994Cougar · 08-07-2008, 10:46

Check out the Fuel Pressure Regulator, i believe that will cause a hard start and a rough idle.

700mach1 · 08-10-2008, 14:28

i have done some more checking and i have found that it does not hold fuel line pressure. if i connect a pressure gauge to the schrader valve, turn the key, the line pressure builds up, but as soon as i turn off the key the pressure drops way back. after talking to the local ford dealer, they told me there was a one-way check valve in the fuel pump and i should replace the new aftermarket pump that i had just installed with a ford pump assy. i did this and the problem still continues. thanks for the tip on the pressure regulator. i am also going to check the fuel injectors to see if one of those in leaking down.