Gentleman (and Ladies), my F150 has merely 80k miles and has never been beaten -- before me.

The engine now stalls intermittently while driving on the highway. The 'Check Engine' illuminates during this temporary condition.
The engine temperature is higher than normal

Any clues?

KOEO and KOER codes are 538 (cylinder balance test failure) and 632 (don't even go there). I have researched the forums and been to many Ford dealerships and as we all know, their support is only limited to vehicles no older than 5 years. ("Buddy, it's 12 years old already...")

Replaced were: plugs/wires/cap, TFI module, MAF (I had on hand), fuel filter AND added an inline HP fuel pump from my 1990, so it's likely NOT a fuel issue.

*there exists NO such "camshaft sensor" on this engine.

Q: How do I clear this frequent stumbling issue and code 538? Might they be related? (the code came up BEFORE the stumbling)

Thank you!

 

You brought your 'antique' to the right place.
Surprise; the 538 code is an operator failure during a test sequence.
The 632 is OD cancel switch not changing state.
Neither code IMO, would be a failure to cause a stall while actually driving.
I think you have another fault causing the stall such as a defective TFI, plug/harness etc. Could even be an IAC/dirty throttle body when coming down to an idle. Neither of these has any codes associated directly to them.
The codes you offer are related to a test procedure that has certain operator requirements while performing KOER testing.
While in a failure mode, you have to determine if it is ignition, fuel fault or air related then go down that path to find the reason.
Look at fuel pressure.
Test for spark.
How is cold starts and hot idle etc.

Man you make me feel old. (i am)!
I still run 88 Bronco II and 90 Lincoln LSC hotrod as well as an 02 truck.

 

Do you expect to get a lot of help here with that username? Go buy a Toyota.

 

Steve, it's all in good fun -- had you been down the path I have with the shoddy workmanship of under-engineered F150 parts and Holier-than-Thou Ford dealerships, I'm sure you'd give the same due credit.

Alas, I'm here for INTELLIGENT responses only, thank you.


BLUEGRASS: Thank you, Sir -- without making my first post into a novel, I DID wish it to be understood that the obvious (air? Fuel? Spark?) questions were confirmed in working order.

Based on your advice, I swapped the TFI and that was not the issue. The TB was cleaned in the winter whilst changing the TPS (that was mounted UNDER the TB) and whether or not associated, there was coolant leaking through -- I disconnected the 3/8" in/out coolant lines to prevent my new TPS from getting contaminated.

As for DTC 538, I was under the impression that it had something to do with the KOER test that checked to see how the EEC could relate fuel management to RPM changes... (too many books say too many things)

Otherwise, there is a hall effect sensor in the distributor that apparently causes this 538 code -- and we ALL know how much fun it is to take Ford's distributor apart... I was hopeful that this would have been a given first-response "cure"...

Update: the engine never stalls when cold, and while doing a break-torque when the engine is hot, it NEVER stalls... (never could get the tires to spin, either!) And again, the temperature guage is slightly higher than the norm. I WILL investigate the fuel pressure while under load as soon as possible. Is there a strainer on the in-tank fuel pump I wonder?

Bereft...

BTW, Bluegrass, what's your Lincoln pulling in the 1/4 mile?