(It's a 93 pickup with a 22re)Truck has ran fine, came home and went to start it the next day and it turns over and soon after starting stalls out.

I've replaced the fuel pump, fuel filter, circuit opening relay, nothing still does it. fuses are good.VAMF is good. Timing was good. It will run off of starter fluid until you stop spraying. I am really stumped please help!

 

Any CEL codes? Even if the light isnt on, still check them. How do you know the AFM is good? Did you check it? I'll bet you my Yota its the AFM.

 

well i think im sure. im kinda a noob at this stuff. this is my first efi. the light is on but the code was for an O2 sensor off the cat. and when the truck trys to start you can hear the fuel pump pumping and that has to work with the AFM right?

 

http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml
http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

 

thanks ill start with that next

 

so i did the diagnostics and the only error code that comes up is code 27(Sub–Oxygen
Sensor Signal.....http://personal.utulsa.edu/~nathan-b...26diagnosi.pdf).. any thoughts?

 

My truck did the EXACT same thing. Took me FOREVER to find out what it was.
Try this...

I had to put a jumper wire in the diagnostic box under the hood to manually provide power to the fuel pump.

It's the small grey box next to the larger black box containing the relays etc...
Pop open the cover and there's a pinout label on the inside of the cap.
I "think" I jumpered +B - FP connectors (been a while so my memory is a little foggy). The 2 pins were very close to each other. When the jumper is connected you will hear the fuel pump running when the key is ON. Once you get the right spot just leave the jumper in and close the lid. Ran my truck 4 years like this.

I've discovered there are 2 circuits that feed power to the fuel pump. The first circuit is when the key is in the "start" position (Which is why your truck will start). The second is when the key is in the "run" position. This is the circuit that is failing. When you let go of the key after starting it goes to the "run" position. The run circuit is dead , the fuel pump stops, and your truck basically "runs out of gas"

I bet you could keep it running if you leave the key in the "start" position (the starter will continue to crank but we're just doing this as a test...)

Give the jumper idea a shot and let me know how you make out.
(I also posted this a while ago with the correct pinouts. do a search on my posts over the last couple of years and you should find it)

Cheers

 

When the key is on the fuel pump runs but as soon as it starts the circuit goes to 0 volts. So I jumped the pump straight to the battery and got the same results. Starts and then dies.