Engine dies at stops/won't maintain idle. No check engine light. Perplexing!

[notamechanicbrad]

I pull a trailer daily with this Expy. The truck has 240k miles on it but has run good with no issues for the last 60k. It burns about 1 quart of oil every 2000 miles and I have to add 12-16oz of water/anti-freeze about once a month (about every 1000-1500 miles). Battery is about 2 1/2 years old (Platinum gel battery) and I do have to jumpstart it if it sits for 1-2 days, so I am guessing something is drawing a small amount of electricity when parked.

1 thing I did notice recently was the water in my radiator has a RED tint to it. I do not know if they topped off my fluids at my last oil change with some red anti-freeze. Thoughts were that possibly the radiator and transmission cooler had a pinhole leak between them. I have been monitoring the water and it doesn't appear to be getting any more red or higher or lower level and I haven't had any problems with shifting gears, etc...

This week I was driving from Dallas to Austin, about a 3 hour drive, and when I exited the highway the truck died. It started right up but I had to start feathering the gas pedal to keep it running. From that moment forward it has not maintained idle without me keeping my foot on the gas. I drove it for about 5 more hours, mostly highway miles (no problems at higher RPMs). No check engine light. It always starts right up but will immediately start sputtering and die. This happens when cold or hot. I've had 2 times I stopped and it continued running for a couple minutes before it died. The RPMs are jumping around between 250 and 750 when it is TRYING to idle.

I unplugged the VTC sensors (1 on each side of the front of the engine) and started the truck and it had no improvement. So, I have plugged those back in.

I have purchased but not installed or tested:
Blown head gasket detector kit
Throttle body
Mass air flow sensor
Coil packs and plugs
Idle speed control valve (Im not sure this truck uses this but read somewhere that may be the issue)

I have in my Cart but not purchased:
Fuel pump
Fuel filter

 

[AWAR]

The first thing I would have checked is the charging and starting system. The alternator may be starting to fail and drawing the battery down when not running. If the voltage drops too low, the keep alive memory can forget how to idle the car. The keep alive memory stores all the learned drivability functions. Repeated dead batteries can lead to computer failures.

Transmission fluid mixed with coolant would look like a strawberry milkshake. If the coolant is still transparent it may be red coolant or Texas water mixed with the coolant.

 

[notamechanicbrad]

Thank you for the informative reply!

I will test the current alternator. But I went ahead and ordered a new alternator. I will install it tomorrow evening. I drive these work trucks a lot of miles so even if the current alternator is good, I see it as preventative maintenance.

If you know... If the computer has forgotten the drivability functions, is it something I could correct thru the Forscan software? I have the software and obd plug. I have done other things with Forscan but nothing like a computer relearn. Or would the computer relearn on its own with a good alternator and good battery?

 

[AWAR]

The computer will relearn as you drive. Disconnect the battery because welding with 12 volts can very exciting.

 

[Gary Waugh]

Could it be water in the gasoline or bad gas? Did you fill up at an old gas station where maybe the gas could have been contaminated? I would try adding a fuel additive to the gas tank and drive it a bit, most additives will bond with the water in the tank and let it pass through the engine and out. You can also try refilling the gas tank with premium gas and see if it will mix with the gas already in the expedition tank and improve things. Contaminated gas is fairly common and usually causes the symptoms you described (stalling at idle and poor throttle response).

 

[notamechanicbrad]

@AWAR - Great! Yes, I was going to bring the battery inside and put it on my battery charger while I do some of the other work.

@Gary Waugh - I fill up at this very busy Murphys every time I make this DFW to Austin to Houston run. They have the lowest price on that stretch of the highway and it's always very busy. Im sure the gas is good and fresh. At this point I have zero miles left in the tank...leaving it as low as possible just in case I decide to replace the fuel pump. Thank you for the suggestion! I appreciate any input!

 

[Stephen Dunster]

Have you checked the throttle body for carbon buildup? The idle air control valve passage may be blocked or the valve itself bad.

 

[notamechanicbrad]

Over the last few days I have replaced the MAF sensor, throttle body, all fuel injectors, all spark plugs, all coil packs, the alternator and the fuel pump. We were able to determine the fuel pump was failing with almost zero pressure at the schrader valve. We expected that to fix the idle problem and did the other items as maintenance on a 248k miles engine.

Once the work was completed I started the truck and let it run at idle for about 10 minutes. It seemed to relearn idle at around 525 RPMs.

CURRENT PROBLEM... When pressing the gas pedal the truck hesitates or wants to die. Once it starts gaining some speed it smooths out and seems to run fine.

There was NO check engine light before we did the work. Now I have code p0453. And my gas gauge reads 2/3rds full but I know there is less than 30 miles of gas in the tank.

Any input would be appreciated!

 

[AWAR]

Is the problem child the 11 EL? If so it may have a fuel pump driver module near the tank and may need the fuse panel modification with the physically larger fuse. There was a recall kit available for the fuse panel on the 09+ F150s.

 

[notamechanicbrad]

Yes it is the 11 EL. I will do a little research and see what info I can find. I am awaiting a fuel pressure tester gauge to see what my actual pressure is at the schrader valve. I hear the new pump coming on but have not checked the actual pressure.

 

[notamechanicbrad]

Current issue... After doing all the installs listed below, the truck idles smooth around 550 rpm but when you put it in gear and give it any gas pedal it wants to stutter and die or backfire thru the intake.

Previous... The truck would not idle but would run fine at higher RPMs. I found the fuel pump was failing and replaced the fuel pump.

Also, as a matter of maintenance on a 248,000 mile truck, I did the following:
Replaced the MAF sensor
Replaced the throttle body
Replaced all plugs and coil packs (all plugs had black carbon buildup more than I would expect)
Replaced all fuel injectors
Replaced the alternator
Replaced the battery
Replaced the purge valve
Did a head gasket test

Any ideas why I am having this issue with the dying or no acceleration or backfire?

 

[Utah Driver]

A vehicle that dies at a stop light can be the torque converter staying locked up.

 

[GaryH]

@Gary Waugh - I fill up at this very busy Murphys every time I make this DFW to Austin to Houston run.

That could be part of the problem. Murphy's gas is not top tier gas. Not enough additives to keep the engine as clean as it should be.

 

[JerryT]

Same stall description happened with my 98 Expy. It eventually through a code and I replaced the idle air control valve. Not expensive at all diy.

 

[czer]

I had a similar rough idle/stalling at idle with my 2004 Expedition. Ended up I had a vacuum leak in one of the rubber lines off the intake manifold. I found it by spraying carb cleaner on all my vacuum lines, when I sprayed the leaking area the idle smoothed out. You can also spray around intake manifold edges to check for leaks there too.

 

[mtbnest]

I pull a trailer daily with this Expy. The truck has 240k miles on it but has run good with no issues for the last 60k. It burns about 1 quart of oil every 2000 miles and I have to add 12-16oz of water/anti-freeze about once a month (about every 1000-1500 miles). Battery is about 2 1/2 years old (Platinum gel battery) and I do have to jumpstart it if it sits for 1-2 days, so I am guessing something is drawing a small amount of electricity when parked.

1 thing I did notice recently was the water in my radiator has a RED tint to it. I do not know if they topped off my fluids at my last oil change with some red anti-freeze. Thoughts were that possibly the radiator and transmission cooler had a pinhole leak between them. I have been monitoring the water and it doesn't appear to be getting any more red or higher or lower level and I haven't had any problems with shifting gears, etc...

This week I was driving from Dallas to Austin, about a 3 hour drive, and when I exited the highway the truck died. It started right up but I had to start feathering the gas pedal to keep it running. From that moment forward it has not maintained idle without me keeping my foot on the gas. I drove it for about 5 more hours, mostly highway miles (no problems at higher RPMs). No check engine light. It always starts right up but will immediately start sputtering and die. This happens when cold or hot. I've had 2 times I stopped and it continued running for a couple minutes before it died. The RPMs are jumping around between 250 and 750 when it is TRYING to idle.

I unplugged the VTC sensors (1 on each side of the front of the engine) and started the truck and it had no improvement. So, I have plugged those back in.

I have purchased but not installed or tested:
Blown head gasket detector kit
Throttle body
Mass air flow sensor
Coil packs and plugs
Idle speed control valve (Im not sure this truck uses this but read somewhere that may be the issue)

I have in my Cart but not purchased:
Fuel pump
Fuel filter

Solved similar problems with my '02 years ago. A couple underhood vacuum hoses had either rotted, cracked, or got chewed by rodents. Fixed a couple of them with liquid tape and bought stock vacuum hose at the store for the rest.