HELP Me!!

[Chief1402]

Hello everyone, I have a '96 240sx (automatic), I've had it for about a year now... It ran perfectly fine with no problems.. about 3 months ago I was t-boned at a intersection, hit the passenger side door and quarter panel... Still drove perfectly fine for about a month.. Then we had the body work repaired... Got the car back and the car has been acting up really bad.. CEL came on, Won't shift properly, I'll be going 20mph and it will all of a sudden shift 1 or 2 times and sound like I'm going 80mph, or it just doesnt want to shift until I let "feather" the gas pedal until it catches I guess.. Had the throttle position sensor replaced and it got rid of the CEL, drove perfect for a day and then all of a sudden back to shifting issues.. sent it back to the shop and they want to charge $600 just to begin looking at all the wiring and what not..

Now, I just want your opinions.. What do you think the problem could be? Fix the problem and keep it? Sell the car, save some money and get another?

[the converted]

Did the cell come back with the shifting issues, or is it still off? Did you file an insurance claim for the accident? Since the problem appeared right after, you might be able to make an argument to get that covered since that wiring is all on the passenger side.

Might be time for a 5 speed swap if that matters to you.

[Chief1402]

Yes CEL came back with the shifting issues. Went away after tps was installed, once shifting issues returned the CEL came back. Only have liability..

[Chief1402]

We ran the codes and there were two codes that came up... tps sensor and gear 3 and 4 ratio is off.

[Hijacker]

I don't think the impact on the pass side caused any direct damage. What it sounds to me is that the energy of the impact either a) knocked loose the inhibitor switch or b) broke the inhibitor switch.

The inhibitor switch is a device on the side of the transmission that relays to the ATCU what position you select with the gear selector. If that guy isn't working properly, I could see the ATCU having issues figuring out how to shift properly, which would relate to a CEL being tossed.

[Chief1402]

Also I forgot another code it threw was a transmission temp sensor in the valve body... As far as the 5 speed swap suggestion.. I'm not sure that if I were to do that it would actually fix the problem at hand...

[the converted]

Here's links to the trans and electrical sections of the FSM for you. It will be a good guide in showing you what to check to see what the problem is.

http://www.nicoclub.com/FSM/240sx/1996/at.pdf
http://www.nicoclub.com/FSM/240sx/1996/el.pdf

[Chief1402]

Ok we checked the switches and transmission looks fine. Switch is as it should be.. Any other ideas?

[AZhitman]

Sounds like the impact may have damaged something internally. The behavior sounds like line pressure issues, which can have a TON of different causes.

Why wouldn't the other driver's insurance have paid for it?

As far as the 5 speed swap suggestion.. I'm not sure that if I were to do that it would actually fix the problem at hand...

How could it not? Everything you listed sounds like a 20-year old Nissan auto trans kicking the bucket.

[Chief1402]

Im just thinking it has to be something electrical. I would think if it were the transmission then it wouldn't be messed up one day and perfectly fine the next. Im just thinking something electrical is what's causing it. If I were to do the 5spd swap the real problem may/may not be replaced.. I just don't wanna sink another $1000 into the car and the problem still be there..

[AZhitman]

Im just thinking it has to be something electrical. I would think if it were the transmission then it wouldn't be messed up one day and perfectly fine the next. Im just thinking something electrical is what's causing it. If I were to do the 5spd swap the real problem may/may not be replaced.. I just don't wanna sink another $1000 into the car and the problem still be there..

A couple things you're saying lead me to believe this might all be a little new to you, so please don't take this as rude - We're here to help.

When components (especially complex systems like an AT) go bad, they don't always give a warning. They work great one day, and the next day, *plop*. And then, a little chunk of band or bearing moves, and *bloop* the car shifts fine... for a while.

So, yes - it could very well be that something internal (hydraulic or mechanical) has gone tits-up. Or, as you say, it could be electrical - But that's no more likely than anything else.

You *have* to go through step-by-step to eliminate all possibilities. Otherwise, you're just guessing - and that doesn't get your ride fixed.

The other thing you said was that swapping to a 5MT might not fix the issue. You DO realize that by tearing out the AT, there's no way you can still have the same problem.

If your car isn't shifting (using hydraulic pressure), then removing that system completely eliminates the problem (whether it's mechanical, hydraulic, or electrical). Replacing it with a system that ONLY relies on your right arm and left foot totally ELIMINATES the possibility of shifting problems.

So, your fear of spending money on a manual swap (and still having the same problem) is fundamentally impossible.

It's like saying, "I'm afraid to eat at McDonald's because they might serve me filet mignon."

[Hijacker]

Last electrical item to take a look at would be the ATCU located behind the ECM in the passenger kick panel. If it doesn't look damaged, inside and out, then it's safe to assume it's working fine.

Dumb question, but it hasn't been asked. Does the trans still have fluid in it? Have you checked to make sure the impact didn't loosen/crack one of the cooler lines, which would effectively drain the trans of all fluid. Since you're step by step eliminating electrical as an issue, start shifting your focus to hydraulic like Greg says. If the internal hydraulic pressures have gone s***, it could be due to a million little things, but the first to eliminate is if the trans even has fluid in it to begin with. I know you'll say "But it's been at a shop, there's no way it could be without fluid." It's very well possible that the shop a) didn't check or b) didn't care.

But on the issue of swapping a 5 speed, there's nothing mechanically or electrically similar between the two, so any hard shifting/no shifting issues the AT has, the MT will work flawlessly.

[Chief1402]

Your right this is all new to me, I'm not trying to sound like I know what I'm talking about. It does have fluid in it, not sure if I mentioned it earlier, but about a week or two after first started having issues there was a puddle of trans fluid under the car (a good size puddle) and so we replaced the radiator and piping and put trans cooler in it.

[AZhitman]

That introduces a bunch of new possibilities. Start it up, let it get up to operating temp, and check the ATF level on the stick.

Typically, when an AT leaks, it starts slow and gets worse. For it to suddenly dump a puddle is odd.

[Chief1402]

Levels are good. We checked.

[AZhitman]

So, it was overfilled. That'd make sense... it got hot, wouldn't shift right, puked some fluid, and possibly contributed to the trans acting up.

[Chief1402]

No we had to fill it back up. The levels are good now.

[Chief1402]

Ok, heres a update. Car still has the problem, tired of messing with it. I've started ordering parts for a 5 speed swap. I'm confused about the brake/clutch pedals though. From what I understand the 5spd brake pedal plugs in just like the auto one.. But what about the clutch? Do I have to have the clutch sensors and do they have to be plugged in to anything?

[AZhitman]

http://www.240sxtech.com/

There are a couple great tutorials in the "transmission" section to walk you through the 5MT swap. Clutch pedal will have a safety switch (which can be bypassed if you prefer).

[Chief1402]

I appreciate the link but I've already got a few swap pages saved. None of them specify if the sensors have to be there or not.. I cannot find any parts locally so I have to order everything online... if I buy a new clutch pedal already assembled for $180 it doesnt look like it has the sensors.. or I can buy each and every part from courtesyparts.com for $150 and have to put it together myself and it would have both sensors..

[AZhitman]

You're making this way harder than it needs to be, but I'm not sure I understand why.

There are no "sensors." They're just pin switches, like the things in your door jamb that tell the dome light that the door is open. And, no they're not attached to the pedal assembly. They're part of the pedal box, which is part of the structure of the dash and firewall.

Did you read the swap articles?

Here's some help finding parts: www.car-part.com - I don't believe for 3 seconds that there's not a wrecked S-chassis anywhere in N AL.

[Chief1402]

I looked at pics of the pedals and there's plug ins for sensors. Yes I read the guides 5 times over. And I'm 90% sure there's no parts to be found in north alabama. Ive posted to craigslist, asked everyone if they know anyone with parts, I've even called every salvage yard in north alabama and None of them have any 240sx.

[Chief1402]

And I'm probably making it harder than it needs to be because I want to do this 150% the correct way. No shortcuts or skimping out on what needs to be done.

[AZhitman]

Ok. I'm telling you this because I've done multiple manual swaps on 240sx's. They're not "sensors". They're two-pin switches. They simply open and either close or open a circuit when the pedal is depressed, telling the car that it's ok to start, because the clutch pedal is pressed.

If you use the site I linked, most places will ship the parts. In fact, if there is an LKQ in your area, they typically can get parts from any yard in North America.

I think if you have the money to buy brand new parts from a dealership (at a 400% markup), you could just take your car to a competent mechanic and figure out what's wrong with the AT.

p.s. I do everything 100% correct. I don't skimp, and I don't take shortcuts. I also don't believe in over-thinking something that's been done thousands of times. We're here to help, not argue.

[Chief1402]

I already was given a quote to look at the car.. $500 just to start ripping things apart to find out what's wrong with it. Im not gonna pay $500 just to diagnose a problem if I can add another $500 and swap everything out. And I'm getting certain stuff new. All I need now is flywheel, transmission and harness, ecu, clutch pedal, and the lower rubber boot and finish plate. Sorry if I sounded like I'm trying to argue.

[Chief1402]

Does anyone have anything I'm needing for sale? Flywheel, trans and harness, ecu, clutch pedal, lower rubber boot and finish plate?

[PapaSmurf2k3]

I THINK you can get away with using the automatic ECU with the manual swap. You just wont have a speed limited anymore.

Does anyone know if I'm wrong/right?

You can get an aftermarket lightened flywheel and basically get an upgrade at the same time as the swap.

[Chief1402]

From my research a auto ecu will work and speed governor is removed. But it will throw codes which will keep the CEL on. Im mainly hunting for the transmission and harness right now.

[Rev_D21]

I would think if it were the transmission then it wouldn't be messed up one day and perfectly fine the next.

That's exactly how mine went. Perfect one day, on a flat bed the next. I replaced mine with a 5 speed. Besides the inhibitor switch and the vss there really isn't too much harness wiring on the auto trans from those dinosaur days.

[Chief1402]

Glad to know I'm not the only one with the problem