Help With Idle Issue

[Lewismwagner]

2001 v6 ...when I crank the car it will idle very rough. After a minute or two it will finally shut off. After several mijutes of letting it warm up i can get it going but anything over 1500 rpms and it stalls out. Now i can park it, remove negative cable to reset, and it will crank and idle just fine for a short time. A couple of things tho, number one spark plug was not tightened all the way. When I did tighten it, car wouldn't even crank. Backed off of it some and it will crank sounding just like it should while misfiring. I guess first thing I should do is see what codes are being spit out. ANY one else had an issue like this with the plug?

 

[wmburns]

If this were my car I would have two concerns based upon your OP.

• Incorrect spark plug used. Perhaps too long. Or maybe the insulator is broken. How about a visual inspection?
• Fuel delivery "issue". Clogged fuel filter or weak fuel pump. This could also be a MAF related.

Start First with the basics.

• Check the battery and alternator.
• If the fuel filter hasn't been changed in a long time, change it.
• Basic tune up which would normally include checking spark plugs and wires.
• Check for vacuum leaks.
• Consider performing a compression and/or leak down test to determine the basic health of the motor.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/

Stop disconnecting the battery to "reset" the PCM. This is not helping the situation. It's erasing the DTC codes needed for trouble shooting and preventing the PCM from learning.

What happens if the MAF electrical connector is disconnected?

Here's some information on an affordable Windows based ODB2 scanner. This could be very helpful in locating the problem.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

 

[Lewismwagner]

thank you for taking the time to reply. hhavent unplugged the MAF sensor yet but my gut feeling says fuel delivery issue also since that plug i pulled was very dry, almost a white look to it. and i looked for a vacuum leak without seeing any but that doesnt mean there is not one. what are the possibilities of the fuel pressure regulator being bad or is this even a situation where that could be an issue? but bottom line, if i had to just take a guess its almost as if the fuel pump were not pumping it all the way up. i just thought that if a fuel pump were bad, then it was bad not working at all.

 

[wmburns]

what are the possibilities of the fuel pressure regulator being bad or is this even a situation where that could be an issue? but bottom line, if i had to just take a guess its almost as if the fuel pump were not pumping it all the way up. i just thought that if a fuel pump were bad, then it was bad not working at all.

Regarding your question. Don't guess, Test! Rent a fuel pressure gauge from your local auto parts store and then you will KNOW. If the fuel pressure is low then it's a fairly straight forward to determine if the problem is in the fuel pump or in the in the fuel rail pressure sensor (OBTW, a 1999+ does not have a fuel pressure regulator).

In the same vein if the fuel pressure is normal that means time is not wasted looking for a problem where it does not exist.

FWIIW, I have seen cases where a fuel pump is weak and not able to move enough fuel. By the same token a bad electrical connection to the fuel pump could "cause" the fuel pump to act like it is bad. Again, one has to perform some tests to provide some direction to the trouble shooting.

Consider the part that the MAF could play in this issue. Let's suppose that the MAF is way under reporting the amount of air entering the motor. What would be the expected symptoms? If you said that the motor would run lean then give yourself a pat on the back.

 

[Lewismwagner]

Figured it out. The return hose on the fuel pump cam loose

 

[Lewismwagner]

Figured it out. The return hose on the fuel pump cam loose