Geez, it isn't often I'm stumped and ask for ideas.
Problem. This started a few weeks ago. Intermittent, it would run fine, then not. Felt like a fuel issue rather than an ignition problem. Truck idles fine. Took it for a drive and it would sputter then backfire when I let off the gas. To me this sounded like a fuel delivery problem. I had been having a few other minor issues, like hard starting when warm. When cold it would light right away, but then stumble like it didn't have fuel. It also was blowing wet black soot out the tail pipe, especially when cold. Really made a mess of anything next to it. Also, a few times, in the morning if I cracked the cold start injector there wouldn't be any fuel in the line.
So, assuming fuel delivery. I know the fuel pump and the regulator should keep fuel pressure in the line with the engine off. So I started there. First, fuel regulator. For the record the regulator for the early 22re is disco'd from Toyota. I had a boneyard regulator from a '92 sitting in my o'crap box, so I tossed it on. I'm not sure why Toyota doesn't supersede the part number to the later regulator. While replacing the regulator I noticed the damper was missing the screw. So I replaced that too (still available). Truck lit and ran good, but then started acting up again.
Suspecting fuel pump because of the lack of pressure after sitting, and the warm start issue, I swapped out the pump with another Denso I had in my o'crap box. This was even though it sounded great when shorted at the dx connector. Lit the truck this morning and the stumble after starting was gone. Took it for a putt and the stumbling and backfire was worse. The fuel filter was replaced with the new engine 5 years ago, so I've ruled it out for now.
OK, could it be ignition? Pulled out more parts from the o'crap box and swapped out the coil-igniter, and the dizzy cap. Nope. Checked the valve adjustment, and the valves were spot on.
Oh, no codes.
So, I'm down to TPS (not likely) or maybe the Ox sensor (ummmm). Or, vacuum leak, maybe. Or?
What does the crowd think? Any more ideas.
The truck should be cool enough to work on, so I'm going to dig my spare Ox sensor out and see what happens.
Problem. This started a few weeks ago. Intermittent, it would run fine, then not. Felt like a fuel issue rather than an ignition problem. Truck idles fine. Took it for a drive and it would sputter then backfire when I let off the gas. To me this sounded like a fuel delivery problem. I had been having a few other minor issues, like hard starting when warm. When cold it would light right away, but then stumble like it didn't have fuel. It also was blowing wet black soot out the tail pipe, especially when cold. Really made a mess of anything next to it. Also, a few times, in the morning if I cracked the cold start injector there wouldn't be any fuel in the line.
So, assuming fuel delivery. I know the fuel pump and the regulator should keep fuel pressure in the line with the engine off. So I started there. First, fuel regulator. For the record the regulator for the early 22re is disco'd from Toyota. I had a boneyard regulator from a '92 sitting in my o'crap box, so I tossed it on. I'm not sure why Toyota doesn't supersede the part number to the later regulator. While replacing the regulator I noticed the damper was missing the screw. So I replaced that too (still available). Truck lit and ran good, but then started acting up again.
Suspecting fuel pump because of the lack of pressure after sitting, and the warm start issue, I swapped out the pump with another Denso I had in my o'crap box. This was even though it sounded great when shorted at the dx connector. Lit the truck this morning and the stumble after starting was gone. Took it for a putt and the stumbling and backfire was worse. The fuel filter was replaced with the new engine 5 years ago, so I've ruled it out for now.
OK, could it be ignition? Pulled out more parts from the o'crap box and swapped out the coil-igniter, and the dizzy cap. Nope. Checked the valve adjustment, and the valves were spot on.
Oh, no codes.
So, I'm down to TPS (not likely) or maybe the Ox sensor (ummmm). Or, vacuum leak, maybe. Or?
What does the crowd think? Any more ideas.
The truck should be cool enough to work on, so I'm going to dig my spare Ox sensor out and see what happens.