Fuel pump issues???

[RunnerRunner]

I've got a 92 3.0 V6 5speed 176k miles. Today while driving I was in 5th gear doing about 65mph I shift down to second to make a right hand turn the turn has a slight incline then I suddenly lose power to the point where I'm doing 5mph and can't get anymore out of it so at the top of the slight incline I drop it to 1st but still don't have much power at all, I'm able to stop and it barely remains idling. It's really stutterie and sounds like its gonna quit so I just get back in and head home (luckily I was only 5 minutes away) on the way home I was able to hit about 35 in 4th with it to the floor. Now it won't even crank.


Forgot to mention that minutes before all of my trouble it was a bit sluggish in 3rd then all of the sudden I had a boost in power.

Does it sound like the fuel pump?

 

[Footofgod]

Yes and no. Change the fuel pump and let us know. Check all your plugs and wires to make sure you are still running on all cyl. Those are the basics to start with.

My 91 has done the same with a bad plug wire.

 

[KidVermicious]

If it won't crank, you've got bigger issues than a fuel pump. Check your battery and grounds first.

If it cranks but won't start, it could be a fuel pump. It could also be timing (somebody check me, the 3vze is non-interference right?), or air/fuel, or lotsa things.

Start with the basics.

 

[RunnerRunner]

It'll crank but not start

 

[KidVermicious]

It'll crank but not start

K. You need fuel, air, spark, and timing. Start with the easy stuff - pull your plugs one at a time, check their condition, make sure the wires and boots are good, make sure they spark against the block when you crank the starter. Make sure you smell fuel on the plugs. Check your timing, make sure your timing belt didn't slip. Shoot some starter fluid into the intake, see if the engine fires then. Make sure there's not a dead rat stuck in your intake.

There's probably lots more to check, I'm no mechanic. But that should keep you busy.

 

[RunnerRunner]

I'll get started tomorrow. If I end up pulling the fuel pump, does anyone have experience cutting an access panel instead of dropping the tank?

 

[Skullduggery]

Before you rip anything apart, get some starting fluid (Eather) and give it a shot before you try to start it. You can just spray it in pull the hose near the Throttle body (it is the small hose with the elbow into the larger hose).

This sounds like mine, I am diagnosing it now. I am to the Knock Sensor now.

Mine runs but is real rough and slow as heck. It runs great for a few moments then goes to crap. I keep getting a Knock Sensor error code, so we will replace it all. I have heard that the Knock Sensor wire is the main issue, so I have ordered a new one it should be here in a few days. I will replace it and I have a used (known good) sensor that I will replace it with.

Let me know what you find with the starter fluid, it should help to diagnose the issue. If it is a fuel issue, it will start. If it is not, it will not start.

Thanks
Randy

 

[RunnerRunner]

Little bit of an update. It'll start without starting fluid but when I hit the gas it wants to cut off but if I slowly add pressure to the gas I'm able to keep it running. While idling it jumps about 500 rpm every second or two then drops back down and jumps again.

I'm honestly dumbfounded by it

It's my first yota so y'all have to bare with me lol

And thanks for all the help!

 

[DC runner]

It could be so many things. Clogged filter. The system is straining for fuel.
Weak pump, again struggling to maintain load.

Bad TPS. Bad Mass Airflow Sensor. Hmm. What else.

 

[RunnerRunner]

It could be so many things. Clogged filter. The system is straining for fuel.
Weak pump, again struggling to maintain load.

Bad TPS. Bad Mass Airflow Sensor. Hmm. What else.

Yeah I know I just don't know where to start lol. I might just pull the pump and see if that's the problem

 

[DC runner]

Well, I know one way to check to see if it is the MAF. You can bypass the maf.

I had my maf go bad and had a hard time tracking a new one down. In the interm I shorted past it. Pretty easy to do. Google, or hopefully someone on here will remember. IN your engine bay at the computer/fuse box you take a wire and hook from Battery + to F1 or something like that. Wait till someone tells your exactly, or google it. This was years ago and I have forgotten which it is exactly.

What it does is bypass the MAF fuel pump control and simply turns the fuel pump to always on. Since your truck has a pressure return line, it isn't an issue. You will get crappy gas mileage as your truck will essentially be in "default" run mode. You can drive it.. but horrid MPG.

Anyway. If that "fixes" it.. then you know it isn't your pump or filter and MAF related. If not.. next step. You can take it somewhere and they can pull the fuel rail line and check the pressure coming from your pump and filter. Modern fuel systems are like 40 or 50/higher psi. Old mechanical inline pumps were like 20psi or such. Too low of PSI on a modern EFI can causes erratic behavior.


Hope those suggestions get you started.