1985 300zx Shifting Help
02-22-2006, 04:30 PM
#1
Registered User
Thread Starter
Join Date: Feb 2006
Posts: 48
1985 300zx Shifting Help
Hey guys, I have a bit of a problem. I have a '85 300zx N/A A/T. I can rev every gear as high as I want except 1st. As soon as I hit 3000rpms in 1st it shifts (even when its mashed to the floor), starting me at about 2300rpms in 2nd, which really kills my acceleration. How can I make it so it lets me go to higher RPMs in 1st?
02-22-2006, 07:46 PM
#2
Registered User
Join Date: Apr 2005
Location: Temecula, CA
Posts: 5,485
you could try one of those manual transmissions 
Sorry I couldn't resist. YOu could try manually shifting the automatic. If its shifting too soon try downshifting it to a lower gear and then upshifting when you hit the desired RPM.
Sorry I couldn't resist. YOu could try manually shifting the automatic. If its shifting too soon try downshifting it to a lower gear and then upshifting when you hit the desired RPM.
02-22-2006, 07:56 PM
#3
Originally Posted by Sp4rt4n
Hey guys, I have a bit of a problem. I have a '85 300zx N/A A/T. I can rev every gear as high as I want except 1st. As soon as I hit 3000rpms in 1st it shifts (even when its mashed to the floor), starting me at about 2300rpms in 2nd, which really kills my acceleration. How can I make it so it lets me go to higher RPMs in 1st?
Originally Posted by jfairladyz
you could try one of those manual transmissions Sorry I couldn't resist.
Sorry I couldn't resist.
Smart ***!
02-23-2006, 07:07 AM
#4
Registered User
Thread Starter
Join Date: Feb 2006
Posts: 48
you could try one of those manual transmissions
I was actually looking for one with a manual tranny, but Id already been looking for a week and was carless (sucked trying to get to work and back) so i settled.
So even when the shifter is all the way down to first gear, it will shift into 2nd?
Im gonna try manually shifting from first to second to drive in about 10 minutes to see if that helps, Ill let you guys know.
02-23-2006, 08:01 AM
#5
Originally Posted by Sp4rt4n
I havent tried shifting it manually, but Im going to in about 10 minutes. What my problem is, is when im in first and it hits 3000rpms (no matter where the pedal is, to the floor or barely being pushed) it shifts, starting me out with no go in second gear. Im wondering if this is adjustable...
Man... hopefully we don't have to give lessons on "how to drive an automatic."
02-23-2006, 06:15 PM
#7
Registered User
Join Date: Apr 2005
Location: Temecula, CA
Posts: 5,485
Thats cause the it's tuned for fuel economy, not performance. If you want to go fast then shift it manually. If you're just cruising then put it in drive and forget it. This is part of what I hate about automatic transmissions: I like to do things myself. I dont want the damn transmission shifting for me.
02-23-2006, 07:06 PM
#9
Registered User
Join Date: Oct 2005
Location: Phoenix, AZ
Posts: 68
You might want to get a new vacum modulator. It effects shifting based on engine load.
It looks like this: http://www.rockauto.com/ref/SMP/SMPD....html?TM59.jpg
It's on the passanger side bottom area. it's the only thing on the trans that has a vacum line on it.
When it goes bad it can start sucking trans. fluid into your intake. Not so much a good thing.
Have you checked the trans. fluid?
It looks like this: http://www.rockauto.com/ref/SMP/SMPD....html?TM59.jpg
It's on the passanger side bottom area. it's the only thing on the trans that has a vacum line on it.
When it goes bad it can start sucking trans. fluid into your intake. Not so much a good thing.
Have you checked the trans. fluid?
02-24-2006, 04:02 AM
#10
The Cake Is A Lie!
Join Date: May 2003
Location: WA
Posts: 5,690
Originally Posted by Sp4rt4n
well, ive always had the 'power mode' button pushed, when I disengage it it goes REALLY slow...
02-24-2006, 06:21 AM
#11
Registered User
Thread Starter
Join Date: Feb 2006
Posts: 48
Have you checked the trans. fluid?
power mode button??? i think you mean the overdrive, which has nothing to do with 1st-2nd. all the overdrive button doess is engage the overdrive, which is like an extra gear for freeway cruising. shift the auto manually, and expect it to not last much longer, or get a manual tranny car. those auto trannys are crap.
And why wouldnt the tranny last much longer?
02-24-2006, 11:21 AM
#12
Doesn't post much...
Join Date: Dec 2004
Location: Escondido (San Diego) California
Posts: 3,617
Originally Posted by Sp4rt4n
And why wouldnt the tranny last much longer?
Rod.
02-24-2006, 01:15 PM
#13
The Cake Is A Lie!
Join Date: May 2003
Location: WA
Posts: 5,690
Originally Posted by Sp4rt4n
No, its power mode, not an extra gear. It lets the tranny rev higher before wanting to shift. (according to the manual)
where is this "power mode" button at? if it's on the shifter, its the overdrive, and it only does what i said in my previous post.
And why wouldnt the tranny last much longer?
02-24-2006, 07:04 PM
#14
Registered User
Thread Starter
Join Date: Feb 2006
Posts: 48
Originally Posted by entropy31
where is this "power mode" button at? if it's on the shifter, its the overdrive, and it only does what i said in my previous post.
Heres a diagram of the difference straight from the service manual:
(Its a big pic, so ill just link to it)
Normal: http://img.photobucket.com/albums/v1...malpattern.png
Power: http://img.photobucket.com/albums/v1...werpattern.png
Originally Posted by entropy31
the autos in these are garbage. they dont like to be pushed too much. believe me, i had one.
hmm... Ive actually been thinking of converting to a manual tranny... maybe I will when I get the money (prolly about early-mid summer
)
02-25-2006, 02:43 PM
#17
Registered User
Join Date: Feb 2006
Location: Anna, TX
Posts: 2
The Power Mode and Overdrive are basically the same thing. It really depends on which Auto trans your vehicle has. Power Mode would indicate that you have an (E4N71B) Automatic trans and O.D. or Overdrive would indicate that you have an (4N71B) Automatic trans. You can find out which trans you have by looking on the Driverside Strut tower ID tag and it will tell you which you have. No automatic likes to downshift to first gear unless you are going slower than around 25mph. You will have to manually shift into first as you press the pedal to the floor. In my experience with these autos if you want to maintain the feel of your efforts. Place your trans in Powermode shift manually thru your gears from 1st to D and finally flip the Powermode off. If the Powermode is off in the beginning it will go from 2nd to 4th and drag down your engine.
02-25-2006, 08:07 PM
#18
Registered User
Thread Starter
Join Date: Feb 2006
Posts: 48
Sorry, Ill get a better picture tomorrow, basically its an on/off switch with the word power on it.
1. I have the E4N71B tranny
2. My problem isnt downshifting to first, its upshifting to second... it does it too fast
3. Thats what Ive been doing, I manually shift until i get up to a steady speed and then turn off power mode, making it rev lower.
Originally Posted by 3RDGENZSTEVE
1. Power Mode would indicate that you have an (E4N71B) Automatic trans and O.D. or Overdrive would indicate that you have an (4N71B) Automatic trans.
2. No automatic likes to downshift to first gear unless you are going slower than around 25mph. You will have to manually shift into first as you press the pedal to the floor.
3. In my experience with these autos if you want to maintain the feel of your efforts. Place your trans in Powermode shift manually thru your gears from 1st to D and finally flip the Powermode off. If the Powermode is off in the beginning it will go from 2nd to 4th and drag down your engine.
2. No automatic likes to downshift to first gear unless you are going slower than around 25mph. You will have to manually shift into first as you press the pedal to the floor.
3. In my experience with these autos if you want to maintain the feel of your efforts. Place your trans in Powermode shift manually thru your gears from 1st to D and finally flip the Powermode off. If the Powermode is off in the beginning it will go from 2nd to 4th and drag down your engine.
2. My problem isnt downshifting to first, its upshifting to second... it does it too fast
3. Thats what Ive been doing, I manually shift until i get up to a steady speed and then turn off power mode, making it rev lower.
Last edited by Sp4rt4n; 02-25-2006 at 08:10 PM.
You guys are making it sound like more work then my manual trans
02-25-2006, 10:25 PM
#20
Registered User
Join Date: Feb 2006
Location: Anna, TX
Posts: 2
You got that right Automatics are for convenience. They are really not designed with performance in mind. The shift schedual for the E4N71B:
0/8 throttle = 10mph
1/8 throttle = 10mph
2/8 throttle = 11 - 12mph
3/8 throttle = 12 - 14mph
4/8 throttle = 15 - 19mph
5/8 throttle = 20mph
6/8 throttle = 21 - 22mph
7/8 throttle = 22 - 23mph
8/8 throttle = 24mph NonLocking and 48mph Lock-Up
If Lock-up does not occur to run 1st at WOT to between 25 - 48mph before shifting to 2nd then you should check The Lock-Up Solenoid, Lock-Up control unit and Sensors, Lock-up control valve, or Governor. If it is upshifting anywhere in this range those items are more than likely good and you might look for a Shift-Kit to improve your shifting issues. Off hand I don't think there is one on the market but you might check with companies like B&M and see if they do. Not everything they make is marketed due to lack of demand. No sense in spending money to sell a few you know. If there is not one available then you might try and find a auto-tranny guru in your area that can make it. Most shift kits for Autos are no more than a bearing and a spring to regulate the hydro pressures differently. Hope this helped in your quest.
0/8 throttle = 10mph
1/8 throttle = 10mph
2/8 throttle = 11 - 12mph
3/8 throttle = 12 - 14mph
4/8 throttle = 15 - 19mph
5/8 throttle = 20mph
6/8 throttle = 21 - 22mph
7/8 throttle = 22 - 23mph
8/8 throttle = 24mph NonLocking and 48mph Lock-Up
If Lock-up does not occur to run 1st at WOT to between 25 - 48mph before shifting to 2nd then you should check The Lock-Up Solenoid, Lock-Up control unit and Sensors, Lock-up control valve, or Governor. If it is upshifting anywhere in this range those items are more than likely good and you might look for a Shift-Kit to improve your shifting issues. Off hand I don't think there is one on the market but you might check with companies like B&M and see if they do. Not everything they make is marketed due to lack of demand. No sense in spending money to sell a few you know. If there is not one available then you might try and find a auto-tranny guru in your area that can make it. Most shift kits for Autos are no more than a bearing and a spring to regulate the hydro pressures differently. Hope this helped in your quest.
Thread
Thread Starter
Forum
Replies
Last Post
Bookmarks
