95 3vze Start/bogging issues when hot

MichaelBlues

New member
Please help! I have a 1995 4runner that I have put THOUSANDS of needless dollars into, just trying to get it to run right, and if I didn't need it to get to work every day, I would have burned it to the ground by now.

Soooo...here it goes. Got the truck for $700 after sitting for a year plus. Second rebuilt motor I put in (first was defective, but under warranty, so I only had to pay for the installation labor and $800 shipping. lol) never ran right. Rough running, weak power. A couple years, and a few thousand dollars later, I've replaced the fuel pump, fuel filters, O2 sensor, knock sensor, plugs, wires, TPS, ECM, every iar and vacuum hose replaced and a few more parts I can't remember.

Latest issue with it is that it won't start back up after warming up, or it bogs down after sitting idling for a while. So, a typical scenario is this: In the morning it may start right up. Usually. Sometimes when it's cold, but almost always hot, it will seem to start fine, and then sputter unless I hold the pedal down 3/4 to full, and rev the shit out of it, and I can hear it kinda clear out, and then it will run fine until I turn it off. At say a drive-through and I'm sitting, either it will go into safe mode and code out, or when I rev, it sputters for a good 20-30 seconds, clears out, and it will drive fine.

Added some gas in the air intake to see if it's not getting fuel. It started up fine and then quickly died like it's getting no gas. Still, checking the bleeder valve shows that there's gas in there. So, it seems heat/fuel/air/spark related. That's pretty much the whole truck...

But I'm narrowing it down to AFM or the coolant temp sensor, or something. The AFM is $200, and I can do that myself. The sensors are all behind the plenum, so I'd probably need a pro for that. Any suggestions before I go blow $200-$500 trying to replace enough junk to fix it?
 
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When the mechanic had it last (for 3 weeks) he said that the full pressure was not kicking in until it was cranked. All I know is that there is fuel spitting out of the bleeder valve.
 
Did you try pinching off the return line from your Fuel Pressure regulator briefly?
Use a needle nose vice grips with some rubber hose and see if it changes the situation. Less than 10 seconds or so at a time.
If your FPR is going bad, you may not have enough pressure to get things running.
 
Could your injectors be clogged from the sitting, then running again? What about the Cat Converter? New? Old? Could it be clogged as well?

Edit for reply @ FPR, i think if it's bad, you can take the vacuum line off of it and let it run and you'll see gas shoot out of the vacuum line within the first 10 minutes appx.
 
Wouldnt that make it not run all of the time? This seems like a heat sensitive issue. Once I let it cool down a bit, it will start up ok most of the time.
 
Oh, and I bought a AFM and hooked it up, just to see if it would do anything. Didnt install it, just plugged it on and moved the flap. No better. Not sure if it would need to be in there to work, but seems like it shouldnt
 
Do you have a spark tester? They are cheap from Harbor Freight. If something electrical is going bad in the coil or distributor it would show up. What happens if you un plug the TPS when idling? how about if you unplug the cold start injector? Any cracks in the pcv hose or grommet?
 

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