Just got a 93 f150, 5.0 302w 2wd a few weeks ago. Was running fairly well for how old and the mileage (250k). Knew it had a vacuum leak from the previous owner. Found the vacuum leak. After that I noticed it idled really high (realistically that realization happened after I brought it home), did some research and changed out the throttle position sensor. Throttle body looked fairly new, IAC valve was brand new, as well as the EGR valve. Put the new throttle position sensor on, which fixed the idle (figured out the old one wouldnt let the throttle body valves close all the way, hence the high idle), but now the throttle cuts off when I try to open the throttle on the road. The engine wont cut off, just the throttle, itll putter around a lil bit, check engine light will flash on/off, then go back to normal. Basically stall out, but then itll cut back on. My first thought was maybe the tps connector was bad, making the voltage/ohm reading too high/low for the fuel system. X'd that out, connector is fine. Next thought is now the fuel system, either fuel injectors, spark plugs, fuel filter, or fuel pump. *Note: one other thing I know from the previous owner is he put new fuel injectors in it. Don't know the lbs/hr on the fuel injectors, but I know the typical range for these 5.0 litres are 18-24lbs/hr. If these fuel injectors are more than 24lbs/hr, could that be a cause why it stalls out with the new tps? My thought process with that is since it wasn't doing this with the old tps, it has to be too big of fuel injectors. The tps couldnt tell that the fuel injectors were too big because it was already busted, but the new tps can, so it tries to compensate for more fuel by opening the throttle more, leading to it stalling out? somewhere along those lines. Let me know what you guys think, have a good feeling I'm on the right track but want more opinions before I pour more money into it.

 

You are begining to chase your tail by guessing and you are not making any sense.. You really need to read either a factory service manual or a Haynes manual to learn how your fuel system works. The TPS is not going to make the throttle blades stay open.Put the original TPS back on because it likely is OK. Things got worse after you changed the TPS. Then begin to logically troubleshoot by checking your fuel pressure and perform any needed maintenance per your manual.Then go from there.Fuel pressure should be 30-45 psi.

 

with your advice taken, i put the old tps back on, read the codes, got code 63 back on cm. With the new one i got code 23 on cm. One way or another i think it has something to do with the tps, either the connector or the voltage. Correct me if im wrong though

 

Here's a link that shows how to test the throttle position sensor. https://easyautodiagnostics.com/ford...sensor-tests-1 This is what I would do next. Also, that website has a pretty good description of what the throttle position sensor does.

 

This guy is good at teaching troubleshooting