F53 460 Engine runs very poorly when heat soaked

[pilotanpia]

My 1995 F53, 460cid runs poorly after being heat soaked.
When engine is cold it runs like gang busters. After a fuel stop and the engine has soaked up the heat due to no airflow through the engine compartment, there is virtually no power at full throttle. Once above 3000 rpm it starts to get power but misses and hesitates. Once up to highway speeds the engine smooths out and runs fine.
I bought the unit with 60,000 miles on it, 6 years ago.
I have replaced the following: fuel pump, spark plugs, ignition module, both coolant temp senders, IAT sender, water pump, radiator, timing cover, thermostat and all related coolant hoses.
I replaced the fuel pump in 2017 because it would only go 35 mph. I was able to hobble it home and make the repair. It was a very easy task, once the fuel was off-loaded. The fuel pump solved the main issue and it runs well until I let it sit for 30-40 minutes during refuelling. One other note, it tends to do better in cooler climates. Not much problem at all in winter months, here in North Idaho.
Most recently, we were coming home from California and our road has one portion about 3/4 mile that is about 7-8% uphill. I could not get past 5 mph using full throttle. It usually pulls the hill at 20-25 mph.
If anyone has any ideas, I would appreciate it.

[philandterri]

We owned a 1996 Bounder 460 Ford. Had the same problem. When the engine got hot and we stopped it would not stay running. Had to be towed a few times but they could never find the problem because it cooled down. Had the fuel pump replaced (in the gas tank}. Ran well for several years.

[RLS7201]

delete

[Gjac]

That vintage 460 and 454's ran hot. I would listen carefully for exhaust manifold leaks, they dump a lot of heat into the dog house and can affect the components mentioned already. Can you hear a slight ticking sound? Does your foot get hot next to the doghouse? Unless you have thick ign wires(10mm or so) this heat can cause these wires to leak and arc to ground. Headers will solve cracked or leaking exhaust manifold problems, add more HP and torque and make for a cooler running engine.

[Eliewin]

Wes Tausend wrote:
...

One more heat susceptible thing, not related to fuel, was the TFI
***Link Removed***. Ford used it in the 80's and early 90's. I'm not sure if it was used on the 460 engines but it's highly probable.

The short story is I ran into this with a 1990 5.0 engine that worked fine previously, then sat around before it was installed in a hot-rod. The engine consistently ran poorly when hot and was even hard to start.

Usually the fix was to remove the module from it's mounting on the distributor and put new thermal paste between the module and a heat sink on the main distributor body itself. Apparently the thermal paste dried out from either time or inactive use.

Wes

When the car is driving, the engine is heated. And if the heat sinks above are not given to thermal paste, the sink is dried by heat. And that's their problems created. So between the module and a heat sink, use the thermal paste.

Thanks for the solution.

[Wes_Tausend]

pilotanpia wrote:

RLS7201 wrote:

Gdetrailer wrote:

pilotanpia wrote:

MT BOB wrote:
Lots of F53-460 fuel pump problems, and threads,on the net.
2 things you can try,cheap and easy,replace the TFI and the fuel pump relay.
Other things to try- at your risk- when it acts up,1-loosen or remove the fuel cap
2- when it acts up, throw trans in neutral, turn off and restart engine.

I tried the TFI aka Ignition Module which is located on the front apron between the left headlight and radiator. So, not exposed to engine compartment heat. Bottom line, it did not resolve the issue.
Thank you.

TFI is only one part, there is the ECM (Engine Control Module) which is the "computer" or "brain" that controls ignition timing and fuel delivery to the engine. ECM has predefined fuel and ignition maps and uses a variety of external sensors (some which you have replaced) to determine timing and fuel delivery.. ECMs where often mounted in the engine compartment near the windshield, not sure where it is on a Chassis build.. Failing ECMs can affect engine performance..

ECM on OP's chassis is on the inside of the fire wall, just in front of the steering column. Not exposed to engine heat.

Richard

Richard,

As it turns out, I didn't replace the TFI Ignition Module. The module that is on there looks really dark gray or black. It says Motorcraft on it. The dialectric compound is dry and powdery. I will get a new TFI but not install it until I get the problem to come back. I will then, immediately replace it. If the problem goes away that should be my solution. Either way since you suggested that i use a new gray one, I'll just leave it in. After all, the one in there is 26 years old.

Richard, which brand do you recommend?

Donald

Donald,

If you dare drive it with the doghouse removed, or quickly removeable, you might have a helper spray the TFI module with something like this coolant to quickly cool it when the RV acts up. This is much quicker and works like a charm. By the time you change out the part, whatever quit will have cooled off anyway. One caveat, make sure if you substitute, that it's non-flammable.

A full can may help if another part must be tested.

We used to do that all the time (very economically) back when consumer electronics weren't throw-away. Maybe 20% of electronic repairs were heat related and intermittent. Of course cheap raw refrigerant spray was common before the Ozone layer problem was recognized. :S

Wes

[pilotanpia]

RLS7201 wrote:

Gdetrailer wrote:

pilotanpia wrote:

MT BOB wrote:
Lots of F53-460 fuel pump problems, and threads,on the net.
2 things you can try,cheap and easy,replace the TFI and the fuel pump relay.
Other things to try- at your risk- when it acts up,1-loosen or remove the fuel cap
2- when it acts up, throw trans in neutral, turn off and restart engine.

I tried the TFI aka Ignition Module which is located on the front apron between the left headlight and radiator. So, not exposed to engine compartment heat. Bottom line, it did not resolve the issue.
Thank you.

TFI is only one part, there is the ECM (Engine Control Module) which is the "computer" or "brain" that controls ignition timing and fuel delivery to the engine. ECM has predefined fuel and ignition maps and uses a variety of external sensors (some which you have replaced) to determine timing and fuel delivery.. ECMs where often mounted in the engine compartment near the windshield, not sure where it is on a Chassis build.. Failing ECMs can affect engine performance..

ECM on OP's chassis is on the inside of the fire wall, just in front of the steering column. Not exposed to engine heat.

Richard

Richard,

As it turns out, I didn't replace the TFI Ignition Module. The module that is on there looks really dark gray or black. It says Motorcraft on it. The dialectric compound is dry and powdery. I will get a new TFI but not install it until I get the problem to come back. I will then, immediately replace it. If the problem goes away that should be my solution. Either way since you suggested that i use a new gray one, I'll just leave it in. After all, the one in there is 26 years old.

Richard, which brand do you recommend?

Donald


Click For Full-Size Image.

[Wes_Tausend]

Gdetrailer wrote:

Wes Tausend wrote:
...

One more heat susceptible thing, not related to fuel, was the TFI
(Thick Film Ignition). Ford used it in the 80's and early 90's. I'm not sure if it was used on the 460 engines but it's highly probable.

The short story is I ran into this with a 1990 5.0 engine that worked fine previously, then sat around before it was installed in a hot-rod. The engine consistently ran poorly when hot and was even hard to start.

Usually the fix was to remove the module from it's mounting on the distributor and put new thermal paste between the module and a heat sink on the main distributor body itself. Apparently the thermal paste dried out from either time or inactive use.

Wes

From memory, if I remember correctly, there was two versions of the early TFI as it has been many yrs since I looked at these systems..

One version was the TFI was mounted directly to the distributor and the other version was a remote mounted version.

The distributor mounted version was typically used in cars and the remote mounted version was used on trucks.

I have worked on the distributor mounted version with frustrating results for a family member. Never ever got that engine to run correctly without it randomly stuttering to death at stop lights.. Changed every sensor, the distributor, coil, the TFI module twice, fuel pump, injectors and the ECM but yet the issue still persisted..

I did find there were some folks on the Internet that discovered part of the issue was grounding issues in the wiring harness, Ford doesn't use a central grounding point and many things are randomly grounded all over the vehicle. Grounding wires from various places in the wiring harness would corrode and fail causing all kinds of strange engine issues.. Family member sold the vehicle before I could try that.

I did briefly look at a pickup truck with poor idling, that is when I noticed on the trucks the TFI was mounted separate remotely from the distributor mounted to the wheel well liner, makes sense since a truck under heavy use generates considerably more heat than most autos..

Gdetrailer,

I believe the distributor problem was exceedingly common. The reasoning is the long story.

The hotrod was a Shelby sportscar replica. My buddy bought a finished car after seeing mine. His engine was giving him fits just like the OP here, especially in slow, hot parades. Gotten busy at work, my rig was still sitting unfinished and gathering dust, so I loaned him my unused distributor. Unfortunately my 'trial' distributor had exactly the same problem, although it had worked flawlessly in the Mustang it came from.

After pulling his hair out, my buddy finally discovered the distributor thermal paste problem (passed down from another hotrodder(s) who had also experienced the gremlin). From what I understand, it takes a special tool to remove the module from the distributor body, so he bought the tool along with some correct new thermal paste. That procedure fixed it right up for him, good as new to this day.

Some trivia...
I think he brought my defunct distributor back maybe a year later. I am not even sure where it is now. By then my employer had suddenly gotten busy and stayed that way for the next 15-20 years. It was a curse. They worked me 80 to 100+ hours a week, mostly out of town. I did little else but work and eventually lost hope in the car until it didn't matter. All I remember is working and sleeping for most of it. The long forlorn chassis project continues to gather dust up on a lift. It's a shame.

Wes

[RLS7201]

The F53 460 up to and including 1997 were EEC-IV OBD-1. The 460 F53s did not have to adhere to the 1996 OBD-2 rules.
The main reason the distributor mounted TFI had such a high failure rate was because of the radiator heat blowing directly on it.

Richard

[Gdetrailer]

Wes Tausend wrote:
...

One more heat susceptible thing, not related to fuel, was the TFI
(Thick Film Ignition). Ford used it in the 80's and early 90's. I'm not sure if it was used on the 460 engines but it's highly probable.

The short story is I ran into this with a 1990 5.0 engine that worked fine previously, then sat around before it was installed in a hot-rod. The engine consistently ran poorly when hot and was even hard to start.

Usually the fix was to remove the module from it's mounting on the distributor and put new thermal paste between the module and a heat sink on the main distributor body itself. Apparently the thermal paste dried out from either time or inactive use.

Wes

From memory, if I remember correctly, there was two versions of the early TFI as it has been many yrs since I looked at these systems..

One version was the TFI was mounted directly to the distributor and the other version was a remote mounted version.

The distributor mounted version was typically used in cars and the remote mounted version was used on trucks.

I have worked on the distributor mounted version with frustrating results for a family member. Never ever got that engine to run correctly without it randomly stuttering to death at stop lights.. Changed every sensor, the distributor, coil, the TFI module twice, fuel pump, injectors and the ECM but yet the issue still persisted..

I did find there were some folks on the Internet that discovered part of the issue was grounding issues in the wiring harness, Ford doesn't use a central grounding point and many things are randomly grounded all over the vehicle. Grounding wires from various places in the wiring harness would corrode and fail causing all kinds of strange engine issues.. Family member sold the vehicle before I could try that.

I did briefly look at a pickup truck with poor idling, that is when I noticed on the trucks the TFI was mounted separate remotely from the distributor mounted to the wheel well liner, makes sense since a truck under heavy use generates considerably more heat than most autos..

[Wes_Tausend]

...

One more heat susceptible thing, not related to fuel, was the TFI
(Thick Film Ignition). Ford used it in the 80's and early 90's. I'm not sure if it was used on the 460 engines but it's highly probable.

The short story is I ran into this with a 1990 5.0 engine that worked fine previously, then sat around before it was installed in a hot-rod. The engine consistently ran poorly when hot and was even hard to start.

Usually the fix was to remove the module from it's mounting on the distributor and put new thermal paste between the module and a heat sink on the main distributor body itself. Apparently the thermal paste dried out from either time or inactive use.

Wes

[Gdetrailer]

MEXICOWANDERER wrote:
What does code extraction reveal?

Mex, a 1995 vintage vehicle would have a very crude ECM with very little diagnostics codes, equivalent to OBD1. Generally with that technology there was a way to short two pins in the diagnostic port then count the MIL light flashes then reference a code chart. Very little data to be had.

1996 was when vehicle manufacturers were required to standardize to OBD2 style ports, but they were not required to fully implement codes for everything at that time so many vehicles up to the early 2000's would have OBD2 ports but the data set was OBD1..

Had a 1993 Ford we bought new, two weeks after taking delivery it started running rough, hard starts and stalling.. No MIL light ever lit.. Back to the dealer.. The dealer ended up having to replace the ECM as a last resort, fixed the problem, never had any isses after that.. It was faulty and couldn't report it's own fault :S

[MEXICOWANDERER]

What does code extraction reveal?

[RLS7201]

Gdetrailer wrote:

RLS7201 wrote:

Gdetrailer wrote:


TFI is only one part, there is the ECM (Engine Control Module) which is the "computer" or "brain" that controls ignition timing and fuel delivery to the engine. ECM has predefined fuel and ignition maps and uses a variety of external sensors (some which you have replaced) to determine timing and fuel delivery.. ECMs where often mounted in the engine compartment near the windshield, not sure where it is on a Chassis build.. Failing ECMs can affect engine performance..

ECM on OP's chassis is on the inside of the fire wall, just in front of the steering column. Not exposed to engine heat.

Richard

Good to know, however, "heat soak" can still apply to the ECM even if is living a a cooler environment. This is especially true if there is failing components inside the ECM (which may be surrounded with potting material which is supposed to reduce vibration and moisture damage to the ECM). If it is potted, it makes heat dissipation of the internal components much slower. Parts tend to heat up faster and stay hotter than they were designed to be at.

OP has a 26 yr old vehicle, fair chance there are failing capacitors, semiconductors or even "cold solder joints" in the ECM at the least..

Op already has changed pretty much every electronic part within the engine compartment without change to the symptoms. ECM is a common part that controls not only ignition but the fuel delivery which will affect engine operation and performance.

I would also suggest taking a look at all of the wiring harness ground connections, not unusual for vehicles of that age to start having failing ground connections and it only takes one corroded ground to foul up the works.

OP's ECM (EEC-IV, catch code MOO0) is not potted. It sits on a heat shield blanket fastened to the fire wall. Yes the Electrolytic Capacitor do fail over time but their failure is prevalent weather hot or cold. Of my 21 years of owning a 95 F53, I've not seen issues with bad solder joints. The Electrolytic Capacitors are the most common issues.

To the OP. Make sure you have a gray Ignition Module. The black ones are for older EFI Fords. Remove the ECM, open its container and look at the ends of the Electrolytic Capacitors. They will be bulging if going bad.

Richard

[RLS7201]

delete