fuel pressure regulator?

[jeepguy]

ive posted about this before my jeep wrangler has been randomly stalling upon start up it will start then it will begin to die and 100% of the time if i catch it before the RPMs drop to low to can feather the throttle and bring the RPMs up to about 2500 then i can release the throttle and it will idle and run just fine but when i dont catch it, it will die then it wont start up again for about 10 mins

Topic

[jeepguy]

yes when i turn the key i can hear the pump running and if i unhook a fuel line it will spray fuel

[dreamer2355]

You need to use a pressure gage when testing for fuel pressure.

[Matt]

Quoted From dreamer2355:

You need to use a pressure gage when testing for fuel pressure.

+100. Have you ever replaced the fuel filter? I forgot to look at your original post.

[Matt]

Now that’s interesting info. First off, the Idle Air Control Valve isn’t a sensor, it’s a solenoid controlled valve on the side of your throttle body. In your particular case, now that you have brought us this info, I would look at your ECT (engine coolant temp) sensor. I could explain how it works, but you seem to like to replace parts. That one is probably pretty cheap.

[jeepguy]

would that make the engine stall when warm?

[Matt]

YES. If the coolant temp sensor is bad, and it makes the PCM think the engine is always cold, then it will dump too much gas into the system, and cause your stalling issue. Have you also noticed a decrease in fuel mileage?

[jeepguy]

as far as MPG it stays at 14, but also i noticed in the cold weather the temp gauge will go to about 230 and stay there a few seconds then in about 3 seconds it will drop to about 180, would that have anything to do with this?

[Matt]

Yeh, i suppose if the coolant temp sensor was stuck on the high end of the scale, it could be giving you a lean condition. You’ve never gotten a check engine light out of this truck? But again, I’m now very suspicious of this sensor, and it’s easy to replace.

[jeepguy]

i will deffinetly replace it and no i never have got a check engine light

[nleonard86]

Before you pull the ECTS, you might want to check it with an ohmmeter. It should read several kOhms cold, down to a few 100’s of ohms (or less) hot. You should be able to unplug the wiring to the sensor to do this test – the sensor doesn’t need power to work.

Chiltons or Haynes should have a chart of temperature versus ohms specific to your Wrangler.

Testing the sensor before you rip it out could save you some time and $$

just my 2 cents

[Trcustoms719]

You can test the ECT sensor.
The PCM probably wont set a codecause it thinks it doing it’s job, If you have a scanner/code reader that can read live data you can see
what the ECT temp reading is, If it’s still reading pretty cold even after having it running for 30-45min then it is most likely bad.

[jeepguy]

yes i replaced the fuel filter, cap, rotor, plugs, wires, injectors, fuel pressure regulator, and crank position sensor, and tomorrow im replacing the IACV

[Matt]

But you STILL haven’t checked the fuel pressure, correct? You just keep throwing parts.

[jeepguy]

i did do a fuel pressure test today, and at idle it stayed at 47 psi, and when i just turned the key to “on” the pressure spiked up to 47 and stayed there after the key was off

[Matt]

Ok, if that’s within the specs, then cool. The IACV could be the problem, because you’ve replaced most everything else. You could try having a friend start the car and tapping on the IACV with the handle of the screwdriver to see if this alters the idle and helps it run to at least do a little diagnostics, but if you are determined to replace it, I hope it fixes your issue. Good luck bud.

[Author]

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