1999 Explorer 4.0 SOHC

[hueycrew]

I have a starting issue. Cranks fine but no start. Broke down after a quick stop at a grocery store. Checked all fuses, relays for fuel pump. Would not start with starting fluid. After I had the Explorer towed to the house this is what I've found.

Electrical - Fuses good, relays good. Fuel pump runs when key is turned on.

Inspected all fuel lines, vent lines. no leaks found.

Fuel filter replaced 1 year ago

Fuel Rail pressure test:
Key on 55 psi and let it sit for 30 minutes - no pressure loss.

Able to start, cycled key 5 times, held accelerator pedal to the floor. Engine started, ran rough at first. Operation smoothed out. Had to keep RPM at or above 1500 keep it running. Pressure reading at 2000 RPM was 65 psi.

When I let off on the pedal the engine stalled at about 1000 RPM. Sputtered and died.

Fuel pump is about 10 years old (replaced once).

No CEL and no codes stored.

Fuel, Air, Spark. I feel that I have these three as I was able to start the engine.

What am I missing?

Help would be greatly appreciated. This vehicle needs to last until I retire in a few years.

- Joe

 

[EB4X]

As you probably have heard your SOHC engine is prone to failing timing chain guides / cassettes.... I'm guessing "a" timing chain possibly jumped a tooth or two... spitballing of course. Did you have / hear any chain rattle / rattle noises prior to this or just before breakdown?

 

[hueycrew]

As you probably have heard your SOHC engine is prone to failing timing chain guides / cassettes.... I'm guessing "a" timing chain possibly jumped a tooth or two... spitballing of course. Did you have / hear any chain rattle / rattle noises prior to this or just before breakdown?

No unusual noises. Was running great at highway speeds, pulling hills as it should. After a quick stop at a grocery store is where I experienced the problem.

 

[donalds]

My vote is fuel pump or a large vacuum leak
Like intake gaskets

 

[hueycrew]

I have a starting issue. Cranks fine but no start. Broke down after a quick stop at a grocery store. Checked all fuses, relays for fuel pump. Would not start with starting fluid. After I had the Explorer towed to the house this is what I've found.

Electrical - Fuses good, relays good. Fuel pump runs when key is turned on.

Inspected all fuel lines, vent lines. no leaks found.

Fuel filter replaced 1 year ago

Fuel Rail pressure test:
Key on 55 psi and let it sit for 30 minutes - no pressure loss.

Able to start, cycled key 5 times, held accelerator pedal to the floor. Engine started, ran rough at first. Operation smoothed out. Had to keep RPM at or above 1500 keep it running. Pressure reading at 2000 RPM was 65 psi.

When I let off on the pedal the engine stalled at about 1000 RPM. Sputtered and died.

Fuel pump is about 10 years old (replaced once).

No CEL and no codes stored.

Fuel, Air, Spark. I feel that I have these three as I was able to start the engine.

What am I missing?

Help would be greatly appreciated. This vehicle needs to last until I retire in a few years.

- Joe

Update. Cleaned the IAC valve. Tested operation. Erratic operation. Power to valve good. Check resistance pin to pin good. Tested pin to case. No good. Have a motocraft valve on the way.
The engine did start and ran well. Would idle however, the engine stalled when I put it in gear.
Intake seals and gaskets were replaced 100k ago.

 

[XploderPhil]

The engine did start and ran well. Would idle however, the engine stalled when I put it in gear.

You might need to check the throttle stop screw, remember it's not used to adjust idle speed.
The other thing, it might just need to relearn it's base idle speed in gear.
Go from N to D, let it idle for 30-45 secs, then back to park. Try this 4-5 times, maybe more.
The ECM learns as it goes along, so cleaning and adjusting the throttle plate and IAC has changed the airflow that it is use to seeing at idle.

 

[hueycrew]

You might need to check the throttle stop screw, remember it's not used to adjust idle speed.
The other thing, it might just need to relearn it's base idle speed in gear.
Go from N to D, let it idle for 30-45 secs, then back to park. Try this 4-5 times, maybe more.
The ECM learns as it goes along, so cleaning and adjusting the throttle plate and IAC has changed the airflow that it is use to seeing at idle.

Thanks Phil - I will.

 

[hueycrew]

I have a starting issue. Cranks fine but no start. Broke down after a quick stop at a grocery store. Checked all fuses, relays for fuel pump. Would not start with starting fluid. After I had the Explorer towed to the house this is what I've found.

Electrical - Fuses good, relays good. Fuel pump runs when key is turned on.

Inspected all fuel lines, vent lines. no leaks found.

Fuel filter replaced 1 year ago

Fuel Rail pressure test:
Key on 55 psi and let it sit for 30 minutes - no pressure loss.

Able to start, cycled key 5 times, held accelerator pedal to the floor. Engine started, ran rough at first. Operation smoothed out. Had to keep RPM at or above 1500 keep it running. Pressure reading at 2000 RPM was 65 psi.

When I let off on the pedal the engine stalled at about 1000 RPM. Sputtered and died.

Fuel pump is about 10 years old (replaced once).

No CEL and no codes stored.

Fuel, Air, Spark. I feel that I have these three as I was able to start the engine.

What am I missing?

Help would be greatly appreciated. This vehicle needs to last until I retire in a few years.

- Joe

Another update.

Replaced IAC valve. Key on , started as expected. Rough idle initially then smoothed out. Warmed to operating temperature.

Rev engine at the throttle body to see if it would stall. After a few tries it recovered quicker. Never stalled.

Shut the engine off for 5 minutes. Cranks but does not start.

Back to the beginning.

I did notice the throttle plate sticks. From a closed position when I move the cam to rev the engine I can feel some binding. Will clean the thottle body and plate.

Found there is more than what I consider normal slack in the throttle cable. I figure it is old age.

I'll check again for vacuum leaks however the way it was running so smoothly I cannot imagine there is a massive leak.

Still no codes, no CEL.

Something is missing. I just have not found it yet.

 

[hueycrew]

Another update.

Replaced IAC valve. Key on , started as expected. Rough idle initially then smoothed out. Warmed to operating temperature.

Rev engine at the throttle body to see if it would stall. After a few tries it recovered quicker. Never stalled.

Shut the engine off for 5 minutes. Cranks but does not start.

Back to the beginning.

I did notice the throttle plate sticks. From a closed position when I move the cam to rev the engine I can feel some binding. Will clean the thottle body and plate.

Found there is more than what I consider normal slack in the throttle cable. I figure it is old age.

I'll check again for vacuum leaks however the way it was running so smoothly I cannot imagine there is a massive leak.

Still no codes, no CEL.

Something is missing. I just have not found it yet.

How do you remove the throttle cable from the throttle plate assembly?

 

[hueycrew]

Realized I never sent a follow up. I downloaded FORSCAN to my phone. Tried to run an IAC test. Would not run the test because the coolant temp sensor (that sends a signal to the ECM) was not operating. Replaced the sensor - Truck started and ran fine. I didn't know there are two coolant sensors. There was more to it however, in the end, it was a coolant sensor.

 

[BTR]

Thanks for the follow-up post. For the 4.0L SOHC, when standing in front of the truck looking at the engine:

• On the left (passenger side) is the Coolant Temp Sender. It doesn’t report to the PCM. It drives the dashboard gauge.
• On the right (driver side) is the Coolant Temp Sensor. It reports to the PCM.

 

[XLTrunner]

Surprised the bad sensor didn't send a PO118 code. Happened to me out of the blue one morning. First start-up of the day and drove about a mile to the gas station. Went to leave and crank/no start. Check engine light came on. About 30 mins later, it fired right up. Replaced sensor and all has been good since.

 

[hueycrew]

Thanks for the follow-up post. For the 4.0L SOHC, when standing in front of the truck looking at the engine:

• On the left (passenger side) is the Coolant Temp Sender. It doesn’t report to the PCM. It drives the dashboard gauge.
• On the right (driver side) is the Coolant Temp Sensor. It reports to the PCM.

Well put BTR!

 

[ducrnd]

I have a starting issue. Cranks fine but no start. Broke down after a quick stop at a grocery store. Checked all fuses, relays for fuel pump. Would not start with starting fluid. After I had the Explorer towed to the house this is what I've found.

Electrical - Fuses good, relays good. Fuel pump runs when key is turned on.

Inspected all fuel lines, vent lines. no leaks found.

Fuel filter replaced 1 year ago

Fuel Rail pressure test:
Key on 55 psi and let it sit for 30 minutes - no pressure loss.

Able to start, cycled key 5 times, held accelerator pedal to the floor. Engine started, ran rough at first. Operation smoothed out. Had to keep RPM at or above 1500 keep it running. Pressure reading at 2000 RPM was 65 psi.

When I let off on the pedal the engine stalled at about 1000 RPM. Sputtered and died.

Fuel pump is about 10 years old (replaced once).

No CEL and no codes stored.

Fuel, Air, Spark. I feel that I have these three as I was able to start the engine.

What am I missing?

Help would be greatly appreciated. This vehicle needs to last until I retire in a few years.

- Joe

just by chance, is the anti theft light flashing???