Engine has no power

hey, I just bought my first Tacoma a few months ago and the engine does not seem to be running at its full potential. it usually has to run for a half hour or so before it idles down, even in 90 degree weather, and doesn't really have much power after second gear. it doesn't act this way all the time just most of the time. just did a tune up, no check engine light and its not using oil so im pretty sure rings are still good. any thoughts to what might be wrong?

 

is the fuel pressure good? spark good? air filter clean?
which engine? 2rz? 3rz? 5vz?
I'd also check the fuel filter.

 

^^this... We need to know MOOARR kind sir!

 

its got a new air filter, plugs and wires, is getting good spark and as of yesterday a new fuel filter. it didnt help with the power loss but it needed it bad, thank you btw. i dont have a way to check fuel pressure accurately. it has a 5VZ engine

 

The high idle almost sounds like a vacuum issue to me? Double check vacuum lines for cracks and whatnot. In the hot weather rubber hoses especially vacuum lines have a tendency to dry out and become brittle. I would start on the intake side of things. Take a vacuum line off and plug it with your finger. If its a good seal it should idle back down, and if not it will stay at high idle.

Is it auto or manual trans?

 

Hey guys, I apologize for being rude and not replying but I've been pretty busy lately. I have checked for vacuum leaks and have found none. I have strong manifold vacuum but almost no vacuum on the other side of the throttle body. I have tried to hook up an OBDI scanner but it wont communicate with my truck???

 

I'm pretty sure your truck is OBDII .

 

1995 is OBDI. 1996 and up is OBDII. It is not uncommon to have problems with communication. I have had that same problem with a few Toyota vehicles running OBDI. Google how to get flash codes. That usually will work faster.

 

I have OBDI under the hood, and a OBDII under the dash in my 95.

 

For shits and giggles I'd look at the EGR valve and/or solenoid. Just a guess.

 

Same in my 95.5 truck.

 

Glad you cleared that up. I wasn't certain. Just assumed that all Tacomas had OBDII. That was a transitional year, I guess.

 

Yeah, those mid year ones get ya. Actually they have the powertrain diagnostic port under the hood on pretty much all of the 1st gen Tacoma trucks. My 1997 has it under the hood. The big one is the under-dash. If the connector under the dash is not a semi-rectangle 16 pin, then it is not OBDII. The mid year introduction of the Tacoma in 1995 forced it to be built OBDII compliant since all vehicles manufactured for the US had to be OBDII after the initial 1995 year.

 

You may want to check your catalytic convertor. It sounds like it is clogged and not allowing a good exhaust. If you have access to a thermal temp reader you need to run your engine up to normal temp and use the temp gun to get the temp of the pipe in front of the catalytic convertor, then take the temp on the pipe behind the cat and see if the temp is lower than the front temp.If the rear temp is lower, you may have a bad catalytic convertor. Good Luck

 

Im learning more about Tocomas every day, my truck does have a 16 pin OBDII connector, so i guess it falls in the 1995.5 year model. The codes are as follows; P0110 IAT circuit malfunction, P0141 Bank 1 O2 sensor circuit malfuntion, P0330 Bank 2 Knock sensor circuit malfuntion and P0420 Cat. efficiency below threshold....I either have alot of things to fix or one really big problem. Any suggestions?