1jz 1/4 throttle same as full throttle?

**Kyosho** · 25-11-2007, 03:59 PM

Is your ISCV working?
Have you adjusted the ISCV bypass screw if it has one?

**naten** · 25-11-2007, 04:09 PM

as far as i can tell its working.

I can hear it click when i turn the motor off, all the resistance values are ok when i tested it. ITs getting power etc etc. I also cleaned it at the same time when i had it off.

AFAIK there is no adjustment on them

**CrUZida** · 25-11-2007, 05:02 PM

Originally Posted by naten

The dashpot is the little black thingy that sits right next to the tps? It doesnt have any wires or anything else coming into it. By the looks of it, it just cushions the throttle closing but i might be wrong?

Yeah. thats the one, and thats what it does.

**naten** · 25-11-2007, 11:12 PM

hmmmmm

i cant see how it would be faulty there isnt much to them. It does have a little adjuster nut on it. Maybe its not shutting 100%

Seems odd they would have like 3 different places for idle screws to go and your not meant to use any of them.......

Can anyone with a 1jz confirm that i should of removed all my idle screws?

**EldarO** · 26-11-2007, 04:03 AM

i had to wind mine in a tad to drop my idle down.

since then (11 months)

ive had no issues, car idles at 700rpm, higher on cold start.

**wilbo666** · 26-11-2007, 05:15 PM

Originally Posted by naten

hmmmmm

i cant see how it would be faulty there isnt much to them. It does have a little adjuster nut on it. Maybe its not shutting 100%

Seems odd they would have like 3 different places for idle screws to go and your not meant to use any of them.......

Can anyone with a 1jz confirm that i should of removed all my idle screws?

Don't remove them...

Have a search for 2JZ throttle body settings, I recall reading in the past the dimensions that the stops should be set too

Cheers
Wilbo

**naten** · 28-11-2007, 07:10 PM

hmmm ive done some searching on here and google and i cant seem to find them

doesnt matter its cracked open slightly and idling good so im not to fuzzed if its 0.1mm off

thanks guys!

**amichie** · 05-12-2007, 09:03 AM

I have found that if your static ignition timing is too far advanced then 1/4 throttle will be good but full throttle will cause the knock retard to cut in making it feel as though its bogged down or strangled.

This doesn't explain your air fuel ratio issues but its worth looking at the static timing.

**CrUZida** · 06-12-2007, 02:10 PM

Can't change static timing on a 1JZ

**naten** · 07-12-2007, 11:03 PM

ill check timing but im pretty sure all is running as it should at the moment.

My disco meter (jaycar a/f) now heads rich instead of lean and the flat spot/hesitation is now gone. This is thanks to a new fuel pump.

Im going over the car and repairing all the major rust so the cars is off the road atm but once its done im going to get it dynoed again just to make sure all is well.

I couldnt find any setting for the throttle body screws so if someone knows where they are hiding please let me know!