ok, give me a break on this, not good at typing stories.
have a 94 f150 302 automatic 224000 miles. truck has been one hell of a unit until recently. drive ability issues like crazy, leaves me sit, no power, pings...etc so here goes... no codes... have to drive with the spout (timing plug) pulled out, if not it will not start sometimes, pull it out and it starts most of the time. pings like crazy (base timing is @ 12) last week had to put a fuel pump in, new pump, 43-lbs of pressure no start. pulled plugs, fouled with gas, new plugs, runs ok. has a miss every once in a while. leave work on Friday, make 5 stops, last stop wont start, have spark, fuel pressure, no start, pull fuel pump reelay, crank and crank, trys to start, put relay back in, it starts, make it home. 2 hours later need to leave, no start.... pull fuel pump relay, crank, no start this time, go out this morning, starts 3 times in a row (took wifes explorer to work, just in case) come home it starts, has miss when giving throttle, wont rev over 3000 rpm with it to the floor, drive around the block, its bad, NO idea...

 

OBD 1 count the flash or buy a OBD 1 scan tool about $30 will tell you where to start looking. At 224k depending on service and how its been driven just might be time to thlnk about replacement.

 

have a scanner, no codes present

 

Does the vehicle still have the cat? If so, suggest to check for cat blockage, quick-n-easy check is for good pulsing at the exhaust at idle rather than a constant flow that indicates a restriction. The inability to get above 3000 RPM raised this flag.

If the spark color is more orange than blue, suspect a weak coil. What condition are the cap contacts, rotor, and plug wires? Any moisture in the cap? Any light show under the hood when dark outside?

Plugs fouled with gas suggest an ignition problem. The TFI and PIP modules are suspect as these no-start problems seem to occur when the engine is already warm - there are shop manual resistance checks for these, as well as for the coil, so to avoid shotgun replacements.

The foolin' with the fuel pump relay suggests the relay may have a problem - should always hear the regular 2-second fuel charge when the key is rolled to On. An intermittent relay problem could explain the starting problem with the wet plugs being a result of low pressure / poor fuel atomization.

Pinging is a concern, especially with the timing advanced to 12. Could be the cylinders have significant carbon buildup, with a SeaFoam drowning or similar combustion chamber cleaner treatment recommended. Could also be cheap gas... Don't think this relates to the starting issue.

Essentially, the problems you mention may be the result of more than one problem, so just have to work through them, with the guidance that until you figure out what it is, keep eliminating what it's not.

Good luck, and keep us posted.

 

There could be a lot of guesses as to what your problem is. My first thought was a bad fuel pressure regulator or some badly leaking injectors.

 

I would start with the easy stuff first...replace all the fuel filters and check that you have a solid 12.8 volts at all locations, check/clean the grounds.

This will give you a base line to work from. check the exhaust for oil/fuel/flow as a baseline...hold a clean rag up to it for a few minutes for color/soot/fuel.

With as odd a list of symptoms and no codes thrown, the common element is ECM, but it is easier and cheaper to rule out the other stuff, first.

 

Sometimes there is corrosion in the electrical connectors. Most of them are self-burnishing. With the negative post disconnected, disconnect and reconnect each sensor nd final control element 5-6 times. Be careful and make sure you unplug the correctly; most of the locks are push down and pull, not pry up. Do this while you're cleaning all the grounds and then see how it runs.

 

TFI was my first thought FWIW

 

No codes at KOEO, KOER, or both? I was having untraceable issues recently that would only intermittently give codes. The problem ended up being the PCM. It was a PITA since it was basically like asking a crazy person to explain their symptoms...

Also, have you checked your vacuum lines for leaks? The vacuum system controls the FPR, among other things that would give these symptoms.

 

replaced all the vacuum lines with rubber ones, also put a ecm in it about 2 years ago (not saying it isn't bad, was a reman)