[suzook82]

Auto Gurus your help is required!!!! - ALL FIXED!!!!!!!!!

G'day all,

I'm having some issues with the auto in my Maverick (90 model). The box itself seems to be shifting fine however it intermittently stops shifting into 4th. Oddly enough,when this occurs if I toggle the switch to activate my dual battery (ie jolt the electrical system) the car shifts into 4th! I was almost certain that the solenoid pack in the valve body was faulty. So a trip down to the boys at wholesale automatic & $1400 later I now have a new valve body & synthetic oil but unfortunately the problem persist!!!
I'm now starting to think it’s the TPS which could be faulty. If so, what would I be looking at price wise & is it a hard job to do yourself? Any help would be GREATLY appreciated!!!
Cheers
Anthony
Oh, even though the valve body didn’t fix my 4th gear issue, it made a MASSIVE difference to the performance of the car. So the money spent was by no means a waste.

 

[USTUCK2]

posibly a earthin or wiring isue on the trans,

 

[offroadjack]

TPS? on a 90?
no such thing!
is it carby?
how about you kick down cable not adjusted properly?

 

[v8manic]

sorry to say but these cars do have a tps and don't use a kick down cable.
Question does the car shift back gears when you accelerate?

 

[USTUCK2]

yeah what v8manic said, has a tps on the carby on oposite side of the cable

 

[v8manic]

have a look at the gregory's manual you can download off here and look at section 7 part b page 3 it tells you how to do a self diagnosis with the computer in these cars.
Cheers Wade
link is http://rapidshare.de/files/39263986/GQServiceManual.zip.html

 

[jtraf]

Yeah the car does kick down when you plant your foot.

Also drives ok most of the time and decides at the most inappropriate of times to drop out of four and all the way to third.. Flick the dual battery isolation switch a couple times is enough to get it to go back into fourth......Most of the time. It takes a little longer when cold but a little hit and miss.

What is a tps switch worth?

And on another note does anyone have a spare auto computer that we could try out?

By the way this is my brothers post just answering so we can track the issue a little quicker.

James

 

[v8manic]

Where abouts are you located?
If it goes away when flicking the battery isolator sounds kinda like you have an electrical fault and if it's all changing back right don't think it would be your tps or your computer but in saying that mine wouldn't go into 4th after i drowned the computer. But it wouldn't change back gears either.

 

[jtraf]

We are in the northern suburbs. But definatly willing to travel to sort it out.

 

[Murraman]

I think it sounds like electrical problem, But I would get a manual lockup switch fitted and see if that solves your problem. I had the reverse problem with mine wouldn't come out of lockup it wouldn't come out till speed dropped below 80km/ph.
I found it very difficult to to find someone who knows exactly what it is, Like you pay for them experimenting. It could be easy or could go on for years trying to figure it out and could cost you a lot more money.
I would give the manual lockup switch a go, Also go back to Wholesale transmissions and tell them the problem still exists. I'm pretty sure they do the manual lockup switch also.
I ended up getting mine converted to manual, drove me mad and end of the day it was the best thing I could have done.
Good luck with it. I have an Ecu, Tps etc. I'm in the Upper Hunter Valley

 

[suzook82]

Firstly, thanks to everyone for your replies!!!

I took the Mav for a drive to get up her up to working temp as manual suggested and put it through the diagnostic test and the results are *drum roll*

The revolution sensor circuit has failed!

This is great that I now know what could 'possibly' be causing my issues however the question remains "what now?". Where do I get this sensor? How much should I expect it to cost? Is it accessible? I guess you get my drift. Once again, any help or advise you can provide will be greatly appreciated!!!

Thanks,
Anthony

 

[suzook82]

OK, I've been doing some reading through the nissan manual I found which if read correct puts me back to square one! According to the manual, there's a long flash to indicate the 'start' of the results which is then followed by the ten flashes (in which ever sequence they maybe).
In my case, I think I've assume this long flash to be a fault code which it isn't!
I knew that was too easy to be true! The stupid car is saying 'All's fine!' which it aint!
*bangs head against wall*

 

[truckster]

So what has Rodney at Wholesale said could be your issue?

 

[suzook82]

Spoke with Wholesale Automatic & unfortunately they can't shine anymore light on the problem. Their theory is to replace cheapest to most expensive part & see whether it fixes the problem. I'm starting to think the TPS maybe my problem. Will take some measurements & even try cleaning it. Otherwise I might just replace it!

 

[AJS]

That sounds like a pretty ordinary (and espensive) way to go about fixing a problem IMO.

Does your car have an overdrive switch on the shifter? If so, it could possibly have something to do with that. Normally the OD (fourth gear) should stay on, and when you activate the switch it drops the box back to third. If there's a problem with the switch or wiring (say an intermittent short) then the box may just be functioning like it's designed to, which could explain the 'no fault' diagnostic result. Just a thought.

 

[suzook82]

Briefly thought about the OD switch but it seems to be working fine.
Decided to bite the bullet and replace the TPS. Put it in this afternoon and took it for a spin. Well, it ain't the TPS!
Wasn't long before it deided not to go into fourth! On the bright side I now have a spare...

Next, take reading from the TPS to see whether it's out of adjustment (doubt it). After that time for the revolution sensor. I'm going to find this bug if it's the last thing I do! Either that or go broke which ever comes first.....

 

[davway]

Drivers side kick panel at your right foot.
Find the fuse for the auto gearbox and replace it.

I ahd an issue in my 89 where it wouldnt select 1st and 4th by itself.
If i manually selected the gear, it was fine.
blown fuse was the answer.

 

[suzook82]

Thanks Davway, consider it done! Would certainly be nice to be such an easy fix.
*fingers crossed*

 

[suzook82]

Well, it's been a while & the problem still exists! I’ve replaced the TPS & Revolution Sensor but no change. Since the installation of an aftermarket cooler the problem seems to have gotten worse. This leads me to believe the issue is with the temp sensor in the gearbox.
I rang the boys at wholesale automatics again (they must hate me) and they too believe it could be the problem considering how many they've replaced in the past. The only issue is getting to this stupid sensor would mean dropping all the fluid & remove the pan. This isn't something I'd like to do considering I just paid $300 to get synthetic fluid put in!!!!!
This leads me to my next question. I've read in the forum somewhere that people are bypassing the temp sensor by installing a resistor in series basically making the computer believe it's at 'normal operating' temp. Could anyone please provide the resistor value and how it was done I'd be most appreciative.

 

[truckster]

Take car to shiners, spray everything around the box/pan with degreaser, then blast the **** out of it for 10mins underneath with their high pressure to clean it. Then drive home park the car overnight.

In the morning blow any remaining water off with compressed air remember to do top of box too, then drain the oil from the box into a clean container. There isnt much that comes out when you remove the pan compared to a full flush. If your going to do it, do it right. The last thing you want is your gearbox thinking it is at the right temp when its not unless you can afford another rebuild.