Diagnose my truck

I have been having problem after problem with the truck since I got a different daily driver. Unless I let the truck warm up forever, it will not go past about 2500 rpm unless I ease my foot off the pedal and it will get a little better. I have cleaned the maf but it hasn't helped this time and some others suspect the converter is stopped up but I think there is more to it. Today when I started the truck for the first time since Saturday it was extremely rough and shaking. I shut it off and started it back and it was pretty much normal. Any ideas?

 

Miles? Plug wires on the 1st gens w/V6 usually need to be replaced every 80K. The symptoms will make you think it's being starved for fuel.

 

284k. I've got new plugs to put in it but I didn't get wires. I haven't changed the wires since I got it about 50k ago

 

Check fuel pressure, tap on the converter to see if you have a loose brick, or hook a pressure gage to the exhaust upstream and measure exhaust back pressure. If it were converters, they tend to get worse the hotter they get...

 

I took the o2 sensor out and I couldn't tell much of a difference. I think it only felt like it had a little more power because of the loudness. The truck does become noticeably weaker after extended amounts of highway driving (30 minutes or so). I don't have a fuel pressure gauge but I'll try to locate one this weekend.

 

Is there a CEL?

 

Not at the moment. It will occasionally pop on for the oxygen sensor. throws the too lean code

 

Sounds like fuel pressure to me. Your air filter is clean I am assuming...

 

Definitely change out the wires.

 

Yeah I blew it out with the compressor and cleaned the throttle body and maf 2 or 3 weeks ago to try to help with the difficult accelerating issue.

 

I'll pick up some

 

Check your cap and rotor and while you're at it check the distributor coil for any obvious signs or cracking, arcing or burning. A bad coil can exhibit different symptoms for different engines and especially when it gets hot like during highway driving. You can check the resistance following the repair manual procedure/specs. And a used denso coil/distributor often is better than an aftermarket.

 

My 99 with 230k had a similar problem, wouldn't rev past 3000, rough idle, no CEL...threw a shit ton of parts at it with no luck. turned out to be bad injectors. All six were plugged with rust. ran like a new truck after I rebuilt them

 

I haven't checked the distributor but I will when I work on it this weekend.

 

I was going to replace them if plugs and wires don't solve the problem and the fuel pump

 

Changed the plugs and it seemed to do a little better. I will know for sure in the morning to see how it acts after it sits all night. Meant to check the fuel pressure but it was cold and raining and I had already put on ball joints and got pissed off at them so I stopped for the day.

 

Clean the throttle body?

 

Yeah

 

Its your ICV. Cleaning it rarely works as soot builds up in the solenoid. Just replace it. I wrote about this in my thread:

https://www.tacomaworld.com/threads/no-start-engine-is-getting-spark-and-fuel-fried-ecu.387148

 

Thanks, new plugs seemed to help a little but it still has a low rough idle at around 600 rpm after warm and it is very weak if i don't give it time to warm up. I'll pull the ICV off and clean it up a little better and I never did unplug the ecu when I cleaned everything so I'll do that. A couple vacuum lines have cracks in the end but I don't think they could be causing much of a leak but I'll try to find out how much of what I need and replace them as well. If none of this works I'll get a new ICV, I just don't want to toss in another $250 when I still need to take care of the clutch and timing belt and a few other miscellaneous things.