I have a 94 ranger, 2.3 I star it and it will sit there and idle great for as long as I let it tun, shut it off and wont restart, have to let it set for about 15-20 min. I have replace everything, and I mean everything! except the engine itself, im stumped, any ideas would be apprciated.

 

i would suspect it is the fuel rail pressure regulator has failed

or even a nearly plugged up fuel filter

 

I have already changed the the fuel pressure regulator and the fuel filter. Even replaced the fuel pump

 

then you have vapour lock

on the end of the fuel rail there is air valve ( same as a tire valve )

have someone to key ignition on ( but no start ) , hold a small plastic pail opposite the valve

depress the little valve rod to evacuate air in the fuel line / rail

 

for some reason i was thinking vapor lock, ill try that when i get home, thanks,, what causes a vapor lock? is that common? and will it return?

 

a fuel filter NO! , but changing out the fuel pump will cause air vapour lock in the fuel line / rail

 

Nope. Not a vapor lock, any other ideas. Has me stumped

 

Code says TP sensor circuit above max volts. But I already changed the TP sensor

 

did you clear the code(s) 1st after you replaced the throttle position sensor

you must clear the error code(s) after you replace a sensor(s) 1st

the only other 2 things i can think of are

the ignition coil is short circuiting internally when the engine has reached normal operating temperature

the engine may run on a lower fuel rail pressure when cold but not warm

could possibly be a failing fuel pressure regulator valve that is not allowing the fuel injectors to operate at the proper pressure ( or it is constantly receiving manifold vacuum even when engine is warm )

( rent a fuel rail pressure tester ) to double check that

 

I replaced all those parts I would hate to think I got a bad part and have to replace the same part again or parts and I did clear the codes when I replaced anything. This is really killing me. I also did replace the coil paks.

 

were those parts OEM replacements or aftermarket

when the engine is warm and running , pull off the vacuum hose to the fuel rail pressure regulator valve and plug it .

shut off engine , then try to restart it ( does the engine restart ) if it does

then the fuel rail pressure regulator valve is faulty

 

no oem parts probably most of the problem. It restarts but is chugging and puking

 

replace the fuel rail pressure regulator valve before you do anything else

sounds like the fuel rail pressure regulator valve is jammed slightly open from the engine heat

use a small hammer and gently whack the regulator valve housing

then restart the engine

fuel pump / throttle position sensor and the regulator valve should always be OEM replacement

even if the parts cost more ( better than most aftermarket parts )

 

ok, tried tried tapping on it and same thing, when it cooled down starts up fine runs around 1K rpm, after it has been running and I finally get it restarted it will either chug, rumble and stall out OR it will start and run around 2500 rpm and when you push the gas it was to choke out, really weird. i really hate to go back through it with oem parts, just want to find that problem part then it will be an almost new truck, let me know if you can think of anything else

 

how long since your thoroughly cleaned out the throttle body

your idle air port may be near fully plugged up

choking out means the cylinders are NOT receiving enough fuel via the fuel injectors

i suspect you have been using fuel with ethanol in it , older style rubber diaphragms are eaten away by ethanol

time for a fuel rail pressure regulator valve , that most likely is causing the chugging / rumbling

NOT enough fuel rail pressure