Ok, I have a 1996 f-150xlt with the 302 in it. Recently I have been having an issue. I can drive it for either an hour or half am hour straight no problems. Then once I get to wherever I'm going and shut it off it has trouble starting up right away, unless I wait half an hour or so.
The truck turns over fine regardless, but if I try to start it right away it starts, but then drops in rpm and starts to idle really rough, and chugs pretty hard, it almost sounds like a muscle car at idle, then shuts off. Then ill start it again right away and it chugs for not even a second and starts up right away ad is fine.
All fluids are clean, oil is black, trans is red, etc.
I tried seafoaming the system but with no avail. I'm wondering if my Pcv valve from my valve cover is letting a lot of oil in maybe, there is no clouds of smoke or any white smoke. I'm at a loss. Thanks ford forums
No I haven't, but with my problems in the past I have replaced the coolant sensor, temp sensor, fuel pressure regulator, cleaned my fuel system, fuel filter, distributor, air filter. It only seems to run rough right after a drive but I have not tried to put the truck in gear.
I let it run and die, or I let it start and shut it off and start it again and hit the gas to open up the throttle and it tries to chug but will rev up and be fine from there on. The battery light comes on when it stalls like on off on off and my oil pressure guage is where it's supposed to be.
And this only started to happen a couple of weeks ago, if I let it sit for a while it starts fine, new cap and rotor, but, there was a coolant leak on the valve cover from what looks like where the coolant sensor screws into the block, I wonder if that gets on the plugs, or it's on the wires inside? I have yet to replace all my plugs yet. Ill try to include a picture
Engine idle depends on the IAC opening control.
If it sticks closed the idle will drop low and could be rough if the throttle plate area is gummed up as well.
I would first clean the Intake Air Controller and the throttle body plate area.
If it does not clear the issue then look at the possibility of the TFI having a heat problem.
A coil breakdown could be a cause, from the heat.
The engine bay heat goes up for several minutes after shutdown so may be a factor.
After restarting the bay cools down somewhat.
The fuel system is a two pipe feed and return.
The pump pressure ahead of the regulator is well above about 60 psi.
The only pressure in the return is from the pipe flow losses since it is un- restricted back at the tank unless the line became restricted at some point.
Vapor lock should never be an issue since the fuel system is normally closed to the outside 'by law'.
Ok, vapor lock the incorrect term, vacuum lock? TKO, is this the same truck you've had issues with before? If the venting for the gas tank has failed or become plugged, you're going to build a vacuum in the tank, which will impede gas flow, particularly if you've driven it for a while. Easy check: next time you drive long enough that you'd expect it to start hard, open the gas cap to equalize the pressure and see if the issue still resides.
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it is a 1996 so it will be a mas airflow truck. . this doesnt explain the symptoms you are describing but a guy never knows. id look into it too. Your fuel pressure is regulated by your fuel pressure regulator. check that second. first check fuel pressure at the rail (key on engine off). then check the pressure (key on engine on). then fire it up and unplug the vacuum line from the regulator and see how it affects pressure.
Sorry I have my responded in a while, work is insane. Yes this is the same truck as before but I fixed it by replacing a pick up coil by replacing the whole distributor.
I have replaced:
Fuel pressure regulator
I have cleaned my IAC before but I can always try again
I took off myanifold months ago and cleaned the whole intake out, with throttle body
I checked my Pcv valve and that was replaced and the hose is clear
I have replaced others as well, I can't remember everything right now
::I will try and open my gas cap after I drive it tomorrow. And usually after a long trip of like half an hour or longer it tries to start then bogs and dies. But as soon as I start it the second time it is fine. It sometimes tries to do the same after a shorter trip and fixes itself fast. I have noticed with my fuel fill ups at the gas station the pump won't keep filling it will click and ill have to hold the trigger down to fill it, WHILE ITS RUNNING. Never had a problem before, but what would cause this vacuum or vapor lock? Plugged vent?
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