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 > Your search for posts made by 'Wes Tausend' found 5 matches.

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RE: F53 460 Engine runs very poorly when heat soaked

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
Wes Tausend 10/19/21 06:49pm Tech Issues
RE: F53 460 Engine runs very poorly when heat soaked

... 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
Wes Tausend 10/19/21 03:03pm Tech Issues
RE: F53 460 Engine runs very poorly when heat soaked

... 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
Wes Tausend 10/19/21 08:14am Tech Issues
RE: F53 460 Engine runs very poorly when heat soaked

... It can't be that hard. But yes, it can be confusing, has happened to all of us... then is simple and obvious when the demon is finally found. The engine only needs three things to run. Compression, fuel/air and ignition. I guess we could randomly brain-storm and maybe somebody will hit upon a useful idea. It almost can't be compression. With one caveat I mentioned earlier. If it has a knock sensor that has an extreme ******-ignition ability, then it could knock and ****** back so far as to kill power, but I can hardly believe it would ****** that much. Unless the computer is in the heat. Or any ignition module, even new does that in your case. EDIT: I see the word r e t a r d starred out above. So if not the above, that leaves fuel and air. Since there should be a dog-house beside the driver, one could drive without the dog-house and have another observer look for problems on-the-go. Except it may run so cool when open, as to be fine if heat is a contributor. Not that it wouldn't bake the occupants as the whole house heated up. But the problems might be that the throttle body is not opening. Offhand, I can't imagine why not. Can the EGR do anything weird on these engines? It's part of the intake. There isn't a soft rubber intake hose ahead of the throttle/mass-air that can collapse when warm... is there? Other things that can be done with the dog-house uncomfortably open is to more directly observe what the vacuum is doing when the problem occurs. By more direct I mean it is easier to connect a vacuum shop-gauge directly to a manifold vacuum source. Otherwise one may run a longer vacuum line to the cabin with the dog-house on and also observe a dash-like vacuum gauge. A similar thing can be done with a fuel pressure gauge. Even an old mechanical oil gauge should be in the range of fuel pressure, or any mechanical water pressure gauge that has a brass bellows. One would want to be be certain that no high pressure (say 45#) fuel leak occurred. I think at least some fuel lines have a built-in fuel-line schrader valve for shop testing. Highway Patrol sometimes tap it (state shop-added valve) for motorists out of gas. It would take a bit of similar jury-rigging to get a non-specific pressure gauge connected. This extreme effort wouldn't make any sense at all until it was insured that the fuel line from the pump and tank was not somehow overheated. Then such a convoluted fuel pressure test becomes a last resort. Lastly, I should explain how compression can change. You probably have iron heads, but if the steel valve inserts in aluminum heads, as I mentioned earlier in http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30288794/gotomsg/30288823.cfm#30288823 come loose, the intake manifold pressure drops to near zero (or ambient) with the throttle open. But even with the throttle wide open, the engine is running under vacuum (or at least some cylinders) when the inserts stick. Some cylinders are 'throttled' by the insert ring following the valve out. When a piston compresses a high vacuum, such as at idle or other port restriction, it forms very little compression. This is the reason the throttle should be jammed open during compression checks, with all the plugs out also of course. For those that want to understand all modern fuel injection, I highly recommend this book: https://www.ebay.com/itm/384450433528 . Charles (edit: not Fred) Probst helped develop modern F.I. ground up and then taught other Ford engineers how to develop their program introduced in 1988. Wes
Wes Tausend 10/17/21 02:25pm Tech Issues
RE: F53 460 Engine runs very poorly when heat soaked

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. Kind of a longshot, but I once sort-of repaired a Corvair (flat, air-cooled aluminum 6 cylinder) that did this when hot. The engine had probably been overheated and several steel intake valve seat inserts had loosened in the aluminum cylinder head. They would temporarily pop back up in place when cold, run fine, then drop back down and shroud the intake valves to self-throttle barely over idle as the engine warmed back up. I temporarily "fixed it" by peening the aluminum head material tighter to the steel valve inserts. It unbelievably ran ok that way for the owner until the engine quit entirely which wasn't long, a couple more months maybe. Otherwise it sounds like the fuel may be boiling in the line somewhere, likely near the engine or less likely close to the exhaust system on back to the tank. Un-pressured gasolines boil between 100 and 400 degrees F, but should usually remain ok, compressed as liquid, for 30-45lb fuel injection. In older carb units, the fuel line pressure was zilch since the fuel pump was not pushing behind it and tended to vapor-lock the pump. Faster speeds do allow a cooler engine compartment that may mysteriously resolve this. Is there a fuel pressure regulator on the line? I'm guessing that there is, if it's F.I. This regulator may be on a return line for the excess fuel that early Ford pumps used. What is the required fuel pressure and does it maintain this? Older carb engines sometimes would cook and boil the carb itself if the exhaust cross-over under the carb (within the intake manifold) was somehow permanently stuck in the high cross flow cold-weather position, or one exhaust down-tube was restricted by a dent or such, causing excessive hot intake cross flow. The cross-over heat is intended to vaporize large raw fuel droplets which can't turn well to the cylinders and therefore hit the intake floor during cold weather. I have also found intermittent intake vacuum leaks on fuel injection that can cause unusual power losses and stalling. F.I. systems run so lean that they are very sensitive to any more air. These type leaks may tend to initially occur during normally high throttle decelerations, such as a vacuum elbow tube temporarily inverting at a break. Good luck to you, Wes
Wes Tausend 10/16/21 04:14pm Tech Issues
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