1jz auto, troubleshooting

[Niva]

owned my soarer for a few months now, had some fun and managed to ignore the fact that it only runs well some of time so im dedicating a few pay checks, time and beer into getting it as close to 100% as possible before chasing more power.



first issues I had was with the car getting hot, turns out from what I can tell the fan hub was never fully engaging. revs high, temp higher and could still stop the fan with a newspaper. new radiator (as old one leaked) and new fan hub and some decent coolant going in it this sat, hopefully that fixes it.


Next on the list is the power, car "seems" to take off from a stop pretty well... goes through all the gears (although with bulk retardation between shifts) but if you floor it doing 60-70k it drops back and sits around 3-4k pulling like a VN.

has new plugs, coil packs repaired... whats next to check / replace?

also anything less than 15ltr in the tank and booting it round a corner is a no go, just cuts out. soarer thing or fuel pump is fucked? checked the filter and it seems all good.



any input on what to start checking etc is appreciated

[Niva]

Just adjust the cable for the gearbox that goes to the throttle body, made it as tight as i could before it ran out of thread.

going to flush transmission fluid tonight as I think I may of cooked the fluid with the dodgy radiator and it getting so hot.

[Brett_J]

Dont just drain the tranny fluid, remove one of the lines to the raidator/cooler, run it into a bucket or something deepish, start the car and let it pour into the container until it stops, measure that amount in new fluid and put it in the box, keep doing this over till you get the new fluid all the way through, usually I go through 12-15 litres or so till I'm happy.
Can you pull the auto box codes to see if its throwing a code?
Also get a MV Automatics shift kit for it, takes about 2 hours max to put in, well worth it, that and a cooler for it too.

[Niva]

I assume I can use cheaper fluid to do the flush with?

Not too sure about the codes, and yeah Im currently trying to find a shift kit. Read up on the install and doesnt seem overly difficult.

trans cooler is on its way.


Im not 100% sure its the auto causing the issue btw :D, for all I know im just low on power

[Brett_J]

My experience with toyota auto's is that they are fickle bitches, I traced one problem of erratic shifts to a tps being slightly out.

Any dexron III fluid is fine, new fluid is better than burnt fluid or old fluid.

Check the fuel pump is properly mounted as well, check its voltage also, check over all the basics like that, fuel filters, anything that will cause it to be erratic.

[Sebdullah]

Fuel pump may just be an issue of lack of baffling in the tank, which you cant do a lot about, mainly just try & sit it as low as possible in the tank

[Sciflyer]

If you have a non-stock pump in the tank you will get fuel starvation if you corner hard and boot it with less than about 1/3 of a tank of fuel... Never had these issues with stock pumps though

Other Fuel pump/FP ECU issues are easy to diagnose, bend a paper clip or bit of wire and put it in the Diagnostics port on the engine between FP and B+

This will bypass the FP ECU and give the pump continuous 12v (don't run it like that forever though...)