won't start without pressing pedal to floor
 

I have a 92 ford F150 302. Everytime I try to start the truck I MUST push the gas pedal to the floor in order to get the thing to start. it is fuel injected. This has always been the case since this engine has been replaced. I'm not sure where the problem lies. I do hear the pump turn on then off. It will not start by just turning the key at anytime. I'm not a firm believer in it being the filter since it will idle. It could be a pressure regulator but I'm not fully convinced nor do I want to just start replacing items until it's fixed. It could possibly be some other issue that I'm not familiar with.

Any ideas?

Sincerely,
Dan

won't start without pressing pedal to floor
 

I guess I've solved my own problem.

It turned out that the temp sensor was defective and open (high resistance around 12 meg!). The resistance of the new thermistor for the truck was around 24k ohms at around 80 degrees.

When you push the accelerator to the floor you turn off the injectors. Since the old temp sensor was open, it was simulating a cold start of around -40 degrees thereby enriching the mix with a lot of fuel. Since the injectors dumped so much fuel, I needed to depress the accelerator to the floor to clear out the fuel in order to start the truck.

16 dollar problem solved!

won't start without pressing pedal to floor
 

That is about the most useful piece of info I have seen here in a while. How did you determine that it was the temp sensor? Did you get a code, a hunch, or what?

Where is the temp sensor located?

Winford;)

won't start without pressing pedal to floor
 

Thanks for the complement. Actually, I asked a mechanic friend about the problem and he said that the f150's have this common problem. I don't know if I agree with that since it's a simple thermistor and they are very robust. I was at a crossroads when he suggested the temp sensor. It made sense on why it could be that and guess what, he was right! I actually had gone through changing the timing chain, spark plugs, rotor, distributor cap, and ignition coil before getting to the temp sensor. These problems helped nail it down.

won't start without pressing pedal to floor
 

I have this same problem on my 92 Ford F150 XLT - sounds like a possible solution, will look into it! Thanks

Epic first post 14 year old thread revival. Crazy, I was 16 when the last guy posted!

I like epic, fits me. lol

I have been trying to fix my 1992 F-150 since last winter. I have changed almost all the sensors plus tune up stuff. Still acted up every other time I drove it. Replaced the engine coolant temperature sensor today, and walla, runs and starts like new. Even though I don't use the truck much, it has been really ticking me off, that I could not get it to run and start right. Now, it's fixed. Thanks again for the great info on your post. Ken Slager, Holland, MI.

This thread is a good indicator as to why it's always good to start with a code scan before doing anything else for diagnosing problems. Code scanning gives you access to the built-in diagnostics Ford built into the ECU. An EEC-IV code scanner is like $25 (or you can use a paper clip and the check engine light). A failed sensor will throw a code. Then you can grab a multimeter, verify it's the sensor that's failed and not the wiring, buy & replace the sensor, and just like that you've solved the problem.