1995 4runner cutting out under a load

I need some help! My 95 4runner started cutting out on me while towing a small load. It would run for a minute then cut out, then catch back again.
I thought it was a fuel problem so I dropped the tank, replaced the pump and replaced the fuel filter. This eliminated the cut out but the engine won't pull above 3000rpm. It just seems to die out and hesitate (its still running). The engine will rev fine in park and it idles fine. I have replaced the entire ignition system(distributer,coil,igniter,wires, plugs,etc.) I replaced all of the fuel injectors, the fuel pressure valve and the TPS. I replaced all of the sensors on the back of the motor and I checked the timing. The engine is newly rebuilt and I went as far as opening the exhaust just to be sure it wasn't a clogged converter. I have more money in the electrical system than I have in the rebuilt motor still no joy. Any help or suggestions would be appreciated.

Welcome to the AF!

Were you able to check the valve timing? Since it was recently rebuilt, the cam timing might be off by a tooth. Valve clearances?

Fuel line pulse damper leaking? (Any smell of gas?) Fuel pressure ok? VSV for fuel pressure control? Pressure regulator?

VSV for EGR? Carbon in EGR valve?

How's the power at low rpm? Is the engine normal or underpowered?

Compression test?

What plugs did you use? Many people say that plugs other than Denso or NGK don't work well.

I checked the timing and have already replaced the pressure regulator. The truck runs normally under 3000rpm but it has gotten hard to start since I replaced the cold start injector relay. It seems to take a long time to catch. I will need to check the valve adjustment and recheck the compression. I'll replace the plugs with ngk's and see if there is any improvement. Thanks for the suggestions I'll let you know what I find.

Don't overlook the fact I said to check the valve timing and not ignition timing.

I checked the compression and it was 160 on all 6 cylinders. I pulled the timing belt cover and checked the valve timing and according to the marks everything lined up right. I am checking the valve adjustment and if I can't find anything thats way out of spec I think I will pull the lower intake to make sure I don't have an air leak.

While you're at it, take a mic/vernier caliper and check the cams for lobe height. I think a fuel pressure problem is more likely...

The cams and the valve clearance all seem to check out fine. I'm with you it seems to be some type of fuel problem. I've already replaced the pump, the filter, the pressure regulator, the fuel injectors and the cold start relay. I have to find some type of fuel pressure guage that I can use to check the pressure. I'm going to retest the vsv and go from there. I'll let you know what I find. Is there any way to test the fuel pressure dampner or is it just a replacement type part.

If it doesn't leak, it's ok

The only reason I mention it is that your engine is known to have a problem occasionally with it leaking.

Well I checked the fuel pressure dampner and the screw that supports the diaphram had fallen out and was loose inside the plactic cover. I ordered and installed a new one from Toyota but my problem remains. I have now replaced the entire fuel system,ignition system, the TPS and all of the sensors on the back of the motor. The only thing I haven't replaced is the ECU is there any to check it to see if it is bad? I am not getting any codes and my check engine light is not on. The engine still cuts out at about 3000 rpm whether you are just reving it sitting still of driving down the road. It still acts like it is running out of fuel but unless something is shutting off the fuel pump or stopping the fuel injectors from firing I can't tell. My local Toyota dealer has been no help at all.

I know you have replaced the pump, but have you actually checked the fuel volume delivered at the fuel rail? You may have a kinked or blocked fuel line. Pressure may be fine, but if your fuel delivery is low, you will never rev.

Did you check/clean your EGR valve and VSV for EGR?

I went back and checked the fuel flow at the return line and when I hot wired the pump I only got about a cup and a half of fuel in 30 seconds. I went further back in the fuel line and tried again before the Pressure dampner and I got about 2 cups. I removed the fuel tank again double checked the pump and the lines. In the hard plastic line that connects the pump with the hard line on the frame I found a kink near the fitting. I straightened the line, reinstalled the tank and rechecked the volume and got about a quart and a half in 30 seconds. I reinstalled everything and it ran great. I still have a few adjustments to make but its easy. Thanks for all of your help!

You're welcome