tristan_nemo

I have a 1986 pickup 4x4, 22re, I've replaced the injectors, fuel filter, fuel rail, spark plugs, wires, flushed out the fuel tank, cleaned the lines, there was a lot of junk in the bottom of the tank when I bought it. But now the only thing wrong with the fuel system is a leak from the top o ring on injector number three, yet the truck still won't run right. It fires up and runs fine for about 10-15 seconds then starts running really rough like its starving and shuts off. What could this be? Vacuum leak? Fuel pump is pushing fuel. Someone help before I light it on fire.

scope103

The fuel pump will shut off if no air is flowing through the VAF; a problem here (or the COR) is a common cause of "starts and runs for a few seconds."

A leaking o-ring could leak enough to out-run the fuel pump and drop the pressure to the injectors. You might need a fuel pressure gauge to diagnose that.

After that, yeah, "running rough" could be a vacuum leak. Ignition timing. Plug wires. Plugs. Gasoline quality. ECT sensor. CSI. CSI Timer.

Do put a timing light on it (with the jumper in) to make sure you're at base timing. Disconnect the CSI to take it out of the equation.

Does it run fine and then suddenly get rough? Or does it limp along and slowly strangle itself?

wallytoo

iTrader: (1)

the fuel pressure in these 22re engines is crucial. if you do not have a functioning fuel pressure gauge (which needs to be added, it isn't stock) in your system, you are throwing darts at any problems with "poor running or stumbling". i am on my 7th or 8th fuel pump in less than 3 years. i finally have a good, functional pressure gauge in my system, so i can immediately determine whether pressure is "in spec" or not. low pressure is more of a problem than high pressure, and the symptoms of a system with low pressure are indeed similar to other problems with these engines (electrical, vacuum, etc.).

i went through a bunch of diagnostics to figure out what was wrong before i had a pressure gauge. i assumed the new pumps were good because they were new. they weren't. if you replace any other parts without knowing the pressure, you are more likely wasting money on replacing perfectly good parts.

tristan_nemo

It fires up strong and runs great for 10-15 seconds then struggles and chokes itself out, makes some sense that the leak may be sufficient enough to drain faster than the pump can catch up, I got the o rings and I'm headed home to do them right now, if that doesn't help it I guess I'll have to dig deeper into the issue

tristan_nemo

Do you have any recommendations on a gauge?

wallytoo

iTrader: (1)

i do. northern tool sells a good one. all the parts needed to add this will cost less than a fuel pump (or injector, or AFM, or TPS).

start with this post in another thread, and keep reading. it will show you the correct parts to get to install a good gauge. DO NOT buy the LCE gauge, but do buy the LCE union bolt replacement that the gauge attaches to.

https://www.yotatech.com/forums/f116...l#post52301033


clearly, if you have an O-ring leak, that needs to be fixed. but other than obvious problems like that, you really need to know the pressure.

wally

tristan_nemo

Thanks Wally!