Yota94ext

So when I start my truck and warm it up it runs fine idles down fine but once I start to drive and put any load on the motor or try to just cruise at the speed limit it Boggs and lopes sometimes pops and backfires but if I let off it idles fine or if I stomp the pedal to the floor it will go and have no power loss at all I've changed cap, plugs, wires, rotor, fuel filter, air filter pulled the throttle positioning sensor of my other truck and still hesitates and runs like crap. Actually ran more responsive with no throttle positioning sensor at all but then engine light is on. but not to sure cuz my engine light doesn't come on or anything don't have the right plug for the scanner I got so can't plug it in and drive to see what codes throw

oldblue

you can still check for codes without a scanner, a blink test with give codes. i would disconnect your battery and drive it for a while though seeing as you have disconnected stuff with the engine running, may have stored false codes. it sounds like its not getting the fuel it needs under load. if you have a fuel pressure gauge you can watch it while driving and see if the pressure drops. a scanner would be nice to look at data, but a voltmeter on the o2 sensor would help tell whats going on as well.

Yota94ext

Yeh that's a good idea thanks

Bigblock

My money is on the VAFM. At idle or WOT your truck is in open loop. Anything in between is closed loop. Could be the Coolant Temp Sensor too.

Yota94ext

So in other words the mass air flow sensor??? Or the coolent temp sensor??? Needs to be done

bone collector

Your truck does not have a mass air flow sensor, it has a Vane Air flow meter.

read thru this, it is the factory service manual.
http://personal.utulsa.edu/~nathan-buchanan/93fsm/

Yota94ext

Ok could that be screwed from a K&N air filter I just put a stock one back in cuz that was a thought in my head

bone collector

what are you talking about???

Yota94ext

I was thinking the oil from the filter screwed the mass air flow sensor but if it doesn't have one would that be it not to sure that's why I'm on here asking someone with some real knowledge for a hand or or an idea to help me get my wheels back on the road

Bigblock

It is an airflow meter but we call it the VAFM. Try a friends vafm see what happens. Oil from a K&N should not bother your vafm like it will the newer MAF's,but it could still be bad. You need to have it checked with a good scan tool.

bone collector

here Is how to check the VAFM.
http://personal.utulsa.edu/~nathan-b...92volumeai.pdf

here is how to check the engine codes. use a paper clip
http://personal.utulsa.edu/~nathan-b...85diagnosi.pdf

bone collector

use an volt meter with a ohm setting to check the VAFM. No scan tool required

Yota94ext

Gunna give it all a shot thanks for the input and brainstorm of ideas to help me diagnose my truck on my own without paying a shop

Gunna go out and give some of these thoughts a trytomorrow

RSR

Oil from K&N's has ruined many VFMs. Essentially, it's a flapper that the oil gunks up until it sticks/no longer functions which leads to breaking the internals...

Also, search on these boards. K&Ns result in worse performance than stock intake, especially with these hot 3vze engines.

Read more on better intake setups:
https://www.yotatech.com/forums/f116...-setup-272137/
https://www.yotatech.com/forums/f116...l#post52104005
https://www.yotatech.com/forums/f116...or-mod-272014/

Yota94ext

So got my truck running good adjusted TPSwith the volt meter, switched out the VAFM from my parts truck and did a few other small things then had it sitting in my driveway warming up and seen a puddle of oil under the truck the size of a dinner plate popped the hood and it's pissing out behind the timing belt cover thinking it's either the timing belt tensioner or the cam is leaking where it comes out to the belt pulley so instead of fixing it I'm pulling the Chevy small block 350 out of the S10 I got and it's turning toy chev sorry boys but this electronic 3.0 v6 is a hunk of s**t as it only has 30000km on it since Toyota put a brand new one in.

Nissanclubman

Sounds for all the world like your AFM is not well. Particularly if you have had backfiring through the inlet manifold.. These Vane AFM do not cope well at all with this. They slam shut and the vane travel stop is poorly located and may result in a cracked vane pivot housing. This will cause the vale to drag on the housing and prevent smooth movement. It may even be stuck and not moving at all... Test out its movement to be absolutely sure it swings smoothly over it full range. Chev swap sound like a great project.. Best of luck