Hey all, could use some help here. I have owned my 1995 F250 Supercab with 460 7.5L Gas engine. I have had no problems until the last month. All of a sudden it started dying and sometimes won't restart. At times it won't start at all. Then, several hours later, and usually when it cools down it will restart. It is almost always when it is hot out or the engine is hot. It always turns over so it is not starter, battery, alternator, starter solonoids, etc.. I have replaced plugs, wires, cap, rotor, fuel relays, fuel filter, starter coil and ignition module to no avail. The truck has dual tanks and pumps so I am mostly certain that it is not the fuel pumps because it doesn't matter which tank I am on. My mechanic says that it is impossible to diagnose because I can't see to get it over to him when it is acting up. HELP! I am frustrated and need my truck to get to work!

I don't know if it is fuel, spark or computer related - any suggestions? You can email me directly as well as post here jeffrey.tritten @ ***.net

THANK YOU in advance

 

OK, remember that an engine needs three things to run: fuel, air, and spark. When all three are there in the proper quantities, the engine will run.

So you have to figure out which one is missing. We can probably rule out air, unless you're trying to start the truck in a vacuum.

So it's very likely either fuel or spark. You can mostly rule out fuel with a fuel pressure gauge. When it acts up, plug the gauge in and see that you're getting enough pressure. It should be right around 40 psi.

You can check spark by pulling one of the wires off and grounding it on the block. If you get a good spark, that's probably not it.

Have you checked timing?

There's also some good advice in this thread: https://www.ford-trucks.com/forums/s...d.php?t=404159

 

...Welcome to Ford Truck Enthusiasts! Take a moment to read the Guidelines, it will help you to navigate through and understand this site.

We are happy you have chosen the best source for Fords!

Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.

 

YOU WROTE:
OK, remember that an engine needs three things to run: fuel, air, and spark. When all three are there in the proper quantities, the engine will run.

So you have to figure out which one is missing. We can probably rule out air, unless you're trying to start the truck in a vacuum.

So it's very likely either fuel or spark. You can mostly rule out fuel with a fuel pressure gauge. When it acts up, plug the gauge in and see that you're getting enough pressure. It should be right around 40 psi.

You can check spark by pulling one of the wires off and grounding it on the block. If you get a good spark, that's probably not it.

Have you checked timing?

-----------

Air is certainly not the issue here. Fuel is fine - even replaced the fuel relays and note that I replaced the EEC relay as well. No problems with Fuel pump or pressure regulator and I am getting fuel at the fuel rails. In addition, it won't even start (when it is not starting) with starter fluid so we can eaily rule out fuel.

Most obviously it is spark related. Note that all plugs, wires, coils and relays have been replaced to eliminate the obvious.

Now that I know it is not the coil-plugs-wires, I think I am down to the computer or the Stator (Hall Effect / PIP Sensor). I have read several times that the Stator can act up when it is hot. I live in Phoenix and any time it is over 90 degrees F, the truck will not start. In the morning it will start just fine and will ALWAYS crank like nobody's business. After running the truck to operating temp (middle of normal on the gauge) it will stall and won't restart until it cools down.

I am fairly certain at this point it is the Stator Assembly (PIP Sensor) which only costs about $30 US. I am tempted to just go ahead and replace is - but I hear they are a real pain to change out. I do not have any sophisticated equiptment to test and I have no idea how to read a Voltometer.

Any other ideas?

BTW, I don't know how to check the timing but when it runs, it runs fine with the exception of some power loss that I had before these problems.

Again, this is a 1995 Ford F-250 Supercab w/ camper edition. It is a 7.5L gas engine with EFI.

Jeff

 

Sounds like the water temp sensor to the PCM to me, thats how they act.

 

SUBFORD WROTE:
Sounds like the water temp sensor to the PCM to me, thats how they act

--------

How the heck do I check that? Excuse my ignorance - what is a PCM? Also, where do I find the water temp sensor and why doesn't it give me any error codes when a hand scanner is hooked up to it?

PLEASE also email the response to me at jeffrey . tritten @ *** . net

Kind Regards,

Jeff

 

I assume you mean the coolant temperature sensor (located by the distributor) is going bad?

EVERYONE NOTE: Fuel and EEC Relays and Ignition Module have been changed out along with coil, starter relays, cap, rotar, plugs, wires, etc (see prior posts).

Note replaced: Crank Sensor, Cam Position Sensor, Coolant Temperature Sensor, Air Intake Sensor, Mass Airflow Sensor.

Still think it is the PIP Sensor / Hall Effect / Stator Assembly.

Where is the genius here? HEEEEEEELLLLPPPP!

Jeff

all replies would be appreciatively sent to jeffrey . tritten @ *** . net

 

that is NOT YET replaced: Crank Sensor, Cam Position Sensor, Coolant Temperature Sensor, Air Intake Sensor, Mass Airflow Sensor.

 

ECT=Engine Coolant Temperature Sensor

A PCM is the Power Train Monitor, It was call the EEC before ford changed its name. Some people call it the Computer but you have at least four different computers in you truck now.
You have PCM or EEC-IV, Rear Anti lock brake, PSOM, Air Bag all in your truck now.

A ECT (Water Temp Sensor) will not give any error codes when you check the PCM for error codes as the PCM has no way to know if the information is right or wrong.

If the truck is hot and the ECT Sensor says it is cold the PCM will dump too much fuel and flood the engine and it will not start. Even if you hold the throttle wide open it will not help it start as the PCM continues to dump too much fuel. But it will start fine when it is cold, as information the PCM is getting is right for the time. The engine will also run rich when hot with a bad sensor.
To check it you would pull off the two wire plug and measure the resistance between the pins, At 70 deg. F it should be about 37k ohms and at about 110 deg. F about 14k ohms.

It is located near the drivers side of the Distributor.


Good Luck

 

Well subford was right about the heat issue with the ECT (Engine Coolant Temperature Sensor). As soon as it got hot out the truck would not start and then it would stall and not restart.

However, I still had a stalling problem so I changed out the Stator (Actually replaced the whole distributor) and walla - it stopped stalling!

NOW - I have little fuel pressure as the rear fuel pump is going bad so I switched to just using the front tank, ~ however the check valve is going out so the returned fuel is flowing into the back tank and soon it willl over flow if I don't siphon it off! Does asnyone know where the check valve is?

 

Its in the fuel delivery module (FDM) which is basically the pump assembly and around $250.

 

I had the same problem a few years ago. check Air mixture sensor? Then look at the computer. Do you have a code reader. Go to O'Reilly Auto Parts, and buy a Equus 3145 by Innova. I spent a little less than 35.00 bucks, if it's computer related you will be able to atleast know what the codes are.
Good Luck

Boy I need to put my glasses on this post is about 6 years old. I was doing a search for computer problems oh well.