HI All,

 

As some of you may know i've been having a bit of bother with my Autobox holding gears too long. It's holding every gear to 3500rpm before changing under normal driving (slight jerk from 1st to 2nd). Also, the car idles at 1000rpm under stress (in drive) and 1500rpm in park.

 

I've also noticed that when i take my foot completely off the accelerator at any rpm between say 2000 and 3000 the car will change up a gear.

 

Just wondered at what rpm the autobox should be changing up and what everyones idle speed is? I can't remember what it was on my last one as i never had any issues so never bothered to notice.

 

Peter

HI All,

 

As some of you may know i've been having a bit of bother with my Autobox holding gears too long. It's holding every gear to 3500rpm before changing under normal driving (slight jerk from 1st to 2nd). Also, the car idles at 1000rpm under stress (in drive) and 1500rpm in park.

 

I've also noticed that when i take my foot completely off the accelerator at any rpm between say 2000 and 3000 the car will change up a gear.

 

Just wondered at what rpm the autobox should be changing up and what everyones idle speed is? I can't remember what it was on my last one as i never had any issues so never bothered to notice.

 

Peter

 

Check your TPS settings before anything else. Also holding the car in drive on the brake at those RPM,s will cook the fluid in the T/C.

Edited July 14, 201411 yr by znut

He you are mate

Cheers guys.

 

yeah, already got the TPS checked with a guide Jeff from Zedworld sent me. Set it to 0.46 as recommended (was at 1 when we first put the multi meter on). This doesn't seem to have made any difference at all.

 

Ted, can't seem to read those docs, or the ones you PM'd me. they are too pixelated.

 

Peter

Ted's quoted pages are found in here:

 

http://www.300zx-twinturbo.com/cgi-bin/manual.cgi

yeah, just got the link and had a quick look. I'm not at all mechanically minded so most of that looks like swahili to me. think i get the general gist though.

TPS should be .44v at a push .45v from all the info ive ever read about it. I know its only 1-2v out but that would make a difference in gear changes

 

Idle should be 850rpm in neutral. So having your revs higher already than they should be, will have an effect.

Cheers. That actually makes sense. If the revs are higher to start with maybe that's why it's changing up higher.

 

Maybe I should look into what's making the idle revs high.

 

Peter

Make sure your throttles are balanced as well, ie. opening at the same time. This can cause wierd problems.. Also check your IACV is working properly. The engine should idle at 750rpm when up to temp..

 

oh, it's important that the tps voltage is rock steady and stable..

Edited July 14, 201411 yr by Steams

Cheers for all the help guys. Must say the TPS voltage did fluctuate between 0.46 and 0.5 a bit?

 

How do I get the idle speed to lower?

Take off the yellow plug of the IACV with engine running and with a flat blade longish driver, turn the idle screw, once the revs are down to about 650 or nearly dying, plug the iacv plug back in and the ecu will take over the idle.

Ah right. Cheers. I'll give that a go at the weekend.

 

For some reason when I got in the car for work this morning and started it it was running a bit lumpy. Did that for about 2-3 mile then started running ok again?

Check for corrosion on your temp sensor.

Oki doke mate. I'll do that too.

 

I'm loosing my wits at the minute with this being my daily driver. When I got up today, started it and it ran lumpy I thought "*****cks, what the feck is up with it now".

 

Doesn't help that I'm a mechanical embarrassment too.