damn gremlins

[drayday55]

i have used the search if anyone is wondering!

got my new motor running last week. sofar 750 miles.

i have had to turn up idle to 900 to 1000 to keep the vibration down and idle smooth.

base timming set good- with the jumper! ( i hear this is not possible with a bad tps)

so the tps im guessing is still good and adjusted properly ( i marked the tps before i took it off the trottle body exactly)

at initial throttle tip in, the motor misses without load, as far as i can tell in gear it goes fine.

yesterday the idle started to be erratic.  not to bad it would not have stalled but im for sure something is up, i am reading the fsm for adjustment spec on the throttle position, but i dont think this is the problem,

any other sensors could cause this?

cold start and idle is fine. so the auxilery air valve is doing its job,
comon gurus! your my only hope/
also what is the function of the sensor directly on top of the thermostat sticks straight up the highest on the motor.  85 efi

[corax]

check for any tears/cracks in the rubber hose between the VAFM and the throttle body?

(which engine BTW?)

[drayday55]

22re 85

[BAMF]

I'd love to help you but I've got the same problem on an 85 22RE.  How bad is the skip?  Just out of curiosity, do you have headers and if so what size is your exhaust?

[axled89]

did you feed it after midnight/ or get it wet at any time.     crazy gremlins.

[corax]

just saw this thread over in another forum . . might be worth a look

here's a similar one

another thread

[Steve_925]

are you sure your not jumping ground on your plug wires

[drayday55]

no, plugs are good, the miss is only at tip in, and is slight, i dont know why toyota made the lower screw on the tps behind the thermostat!

it would be so easy to adjust! but no!!

well, the knock is steady now, im pretty sure its from not resizing the crank side of the rods.  only thing i did not do.  dont ask why!
i put on the lc engineering oil pressure adjuster, and added some stp goo hope it helps a little.
this is nothing damaging but annoying!

[MC387]

I had an 86 that did the same thing.  Misfire under light load that is.  I tried just about everything.  What I found is that it would run lean, I tried adjusting the AFM, but it didn't help.  The ECM was leaning it out due to 02 sensor input.  I tried diffrent o2 sensors, It always did it.  The only way to make it stop was to unplug the 02 or, give it a false lean signal.  I  finally fixed it when I swapped in a 3.4.

[emsvitil]

A long time ago I seem to remember something similiar............

I changed the 1-wire O2 sensor to a 3-wire heated O2 sensor and the problem went away....

[drayday55]

i know the 3 wire o2 is to heat it up i did not know it is compatible,

if this motor gives me grief i want to install a diesel vw or a 4.3

[emsvitil]

Ground 1 of the additional wires, and put the other on a 12v positive ignition source.........

[drayday55]

well, seems like the knock is getting louder.  anyone in san diego have a short block for sale?
cheap?   i just sold my old long block for 150  im such a dumbass for doing so!