as listed in the title my newly acquired 1992 f150 2wd auto 302 will not rev past about 2000rpm in idle or drive without completely falling on its face(literally flooring the car does nothing but make more noise but produces no power) and bucking horribly and the intake noise changes from a normal sucking sound to a gurgle vacuum noise, the truck starts and idles flawlessly with perfect 10degrees of timing with spout out and advances properly with it in. The Truck is completely un-drivable and only does about 20mph and will maybe slowly gain more speed but any touch of the peddle does nothing.

new parts replaced
new cat
02 sensor
TPS (properly adjusted)
plug wires
TFI ignition module
Reman PCM
new Fuel pressure regulator
plugs not that old
new fuel filter
new upper and lower intake manifold gaskets
cleaned and properly working IACV
new MAP
New coil

Ran KOEO codes and did KOER codes too. KOEO codes 31 85 33 34
KOER codes 31 25

this didn't really reveal anything that would help my situation,


so my best guess are as follows, MASSIVE air leak causing a lean condition so the truck wont rev, PCM not happy with something and cutting timing, spark, and or fuel.

I tried spraying fuel into the throttle body to see if it would pick up some revs while I was simulating the issue but did nothing leading me to believe its not a fueling issue, also with the fact that the truck has dual tanks dual fuel pumps and both pumps don't change the problem.

I am at my wits end! ANY IDEAS???

 

What is the fuel pressure. The system should make and hold 40psi with vacuum removed from the regulator, if it's significantly less than that the motor will be a 90lb weakling.

 

well seeing the fuel pressure regulator is new and didn't change anything when I replaced it, and when I switch from rear to front pump nothing changes I would suspect its not a fueling issue. I should double check with a gauge but im pretty sure that's not the issue

 

I've seen two bad pumps before, and if you have a bad FPM or selector valve, you could be dumping fuel pressure. Just throw a fuel pressure gauge on it.

You may also want to recheck your codes. 92 is a transition year, and some trucks generated 3 digit codes depending on build date.

 

how can I test the FPM? and can I test the selector valve? where is the best place to rent or buy a fuel tester

 

just tested fuel pressure ... 38 at idle with fpr hooked up, jumped to 45 with vac removed. fuel pressure increased with rev

 

Fuel pressure is good. Have you rechecked the codes yet?

 

You didn't mention cleaning the fuel injectors, sounds like they're dirty,and about the only thing left to check.

 

I just took a video. injectors don't go bad in 3 miles all at once. only showing code 34 for egr or whatever

 

Dirty injectors may explain why it starts and idles, but pukes under load

 

pukes is a good term for the sound its making . I will add that to the list.

 

video of problem

 

I didn't say they were "bad' I said they may be plugged. If they are the original injectors they're 21 years old. If you look at the end of a ford injector the holes are smaller than the point of a pin, and have be cleaned with a special solution. But don't take my word for it I've only been working on my 89 for about 15 years now

 

I have the newer yellow top injectors, it was running pig rich before this issue and I didn't do anything to them, im not ruling them out but take a look at the video

 

EGR code indicates the computer thinks the EGR valve is not closing. Trying unbolting the EGR and blocking it off with something, such as gasket material from a local parts store.