Starts but won't run

[RBARRON]

My 2002 explorer xlt 4.0 has recently had new timing chain, wires, plugs,water pump at 150k miles. Ran great for a couple of months. stopped at a light and it died and would start but not run when pressed the gas peddle. Just coughs sputters and dies. Checked fuel rail and have 60 psi so pump is good.
What else can it be???

 

[LMHmedchem]

My 2002 explorer xlt 4.0 has recently had new timing chain, wires, plugs,water pump at 150k miles. Ran great for a couple of months. stopped at a light and it died and would start but not run when pressed the gas peddle. Just coughs sputters and dies. Checked fuel rail and have 60 psi so pump is good.
What else can it be???

It's best to start with engine codes. Maybe the engine will tell you what is wrong. If you don't have a scanner to check, you can pick one up pretty cheep. It's a necessary item to have if you are going to do your own repairs. Most auto parts stores will check the codes for you for free. That can be an issue if you can't drive at all, so you may want to think about getting one. You can just get a USB connector that will connect to your laptop or tablet.

You can get a standalone unit at an auto parts store starting at about $30. The usb connections for your laptop are nice because you can use them to accumulate data while you are driving and store it for later analysis. These also go for around $30 on amazon.

LMHmedchem

 

[Mustang Guy]

Could be any number of things and getting it scanned would be where to start. My first "guess" would be the TPS. In any case I doubt it's anything serious and should be easy to diagnose.

 

[lincolnshibuya]

try cleaning your IAC, normally if you have a failing IAC it will die at idle and come to life only when you press the throttle.

 

[RBARRON]

Thanks, sounds like a great idea. I will check Autozone

 

[RBARRON]

2002 explorer 4.0 STARTS BUT WON'T RUN UNDER ACCELERATION

i BOUGHT THE TEST UNIT AND RAN IT ON THE EXPLORER. NO OBD ERROR CODES SHOW IN THE COMPUTER. i KNOW THERE ARE MORE DETAILED TESTS TO BE RUN BUT IF THE TIMING CHAIN SLIPPED A COG OR TWO DUE TO THE TENSIONER NOT BEING REPLACED AT THE TIME THE CHAIN WAS REPLACED WOULD THERE BE AN OBD CODE PRESENT?
ANOTHER SUSPECT IS THE FACT THAT ONE OF THE CAM BOLTS WAS MISSING THE FIRST TIME IT FAILED. IF THE REPLACEMENT BOLT WAS WALLOWED OUT AND REPLACED IT MIGHT HAVE COME LOOSE AND ALLOWED THE CHAIN TO SKIP A COG. THE CHAIN WAS REPLACED BY A SHOP
ANY SUGGESTIONS?

 

[TechGuru]

Could be any number of things and getting it scanned would be where to start. My first "guess" would be the TPS. In any case I doubt it's anything serious and should be easy to diagnose.

^^^^THAT^^^^

A failed throttle position sensor would cause the engine to get more air when you press the pedal and open the throttle but no increase in fuel to match the increase in air thus killing it.

 

[RBARRON]

Thank you so much. I will try the TPS next

 

[TechGuru]

Thank you so much. I will try the TPS next

Check your mass airflow sensor too while you're at it, I believe TPS and MAF work together to determine fuel needed.