Tranny Problems - ATX

[GOTBASS]

Just recently my car is having problems shifting into 2nd gear when I'm on the gas. The other night, I was racing a Cavalier and when it got to 6K-6.5K it felt like the rev. limiter kicked in, I let off a little, and it shifted to 2nd. Same thing happened yesterday. I was in the gas, and up in the 6000 range, it starts to "sputter", and won't shift to 2nd until I let off a little. This is the first time it's happened.

It may be a coincidence, but the first day it started, it was 90 degrees out, and had been at the most 65 before then.

Anyone have ideas to what it is?

Shon

[sonza68]

How much gas did you have in your tank? When I was having fuel pump problems, my car would not shift from 1st to 2nd unless I let of the gas. The motor would also sputter (and even misfire after it got worse) if I stayed on the gas at high revs.

[GOTBASS]

Yeah, kinda wondered that... I had 1/2 tank though the other night. almost 2 years ago, we had a problem with our fuel pump. It was replaced, and has been running good since until the past few months. But I think it is going out.... didn't think it would affect shifting though.

Shon

[KoochieCivic]

i have the exact same thing happen to me... when I'm low on gas and floor it, it revs high and jerks my car back and forth before switching to second. It's not your tranny though, it's the fuel pump and I'll be taking mine into the dealer soon.

[GOTBASS]

Thanks guys!

Shon

[OverLamer]

that could be a problem. If I remember right you were going to install a n2o kit. I would wait to install it to see if this is a one time thing or if this will be a repetitive problem. The last thing you want to do is hit fuel cut while spraying, also if there is a problem with the tranny another 50-75hp will definately not help it. ;) Just make sure if it keeps happening to get it looked at, before you do anything else that puts strain on the car.

[GOTBASS]

I filled it up yesterday, and ran some "tests" on in. The Tranny is running fine now. I just don't quite understand how the fuel pump affects shifting like that. But trust me, I will definitely get a new fuel pump before installing N20.

Shon

[sonza68]

I think it more the computer as opposed to the tranny that is acting funny. The TPS is telling the computer that you are at WOT and it sets the shift point at say 6500 rpm. When the fuel pump can only deliver enough fuel to rev to 6000 rpm, the computer gets fooled and holds 1st gear until you let off the gas, lowering the shift point. Note that this is my understanding of the ATX shift logic, but I am by no means an expert on the subject.

[Wick]

Makes sense to me!:shrug:

[exigent]

Ive had this exact problem for months... it only gets worse... it started for me at only 1/8-1/4 thank and now its anything less then 1/2. Somplace in the fuel deleivery system there is a fault... my current guess is the EVAP system. My solution for the time being is going to be a strait vent line from the fuel tank. Yes i understand that is bad for the trees but i dont care... im not replacing $500 worth of emisions components. If its not that... then im going to look into the fuel pickup on the pump. A fuel pump does not fail only when the gas tank is empty.... when a fuel pump fails it will do it all the time regardless of tank volume. If you had an a/f gauge you would see it go full lean like i do when the symptom occurs... eventually you will get as bad as my car and i hope it doesnt take that long for a fix to come out. There is a definate defect somplace in the fuel delivery system and im going to find it... i have too.... Its either that or im going to replace the fuel system alltogether with a standard pump and return line.... hell it would be cheaper then a oem pump and a few valves...

[KoochieCivic]

Same thing with me exigent. It only used to act up when I had about 50 miles left, but now it does with half a tank. It just keeps getting worse and worse.

[Cougar0102]

I just made a post about the same thing before I saw this - my bad. Anyway, I'm experiencing identical problems. I had never thought of it only doing it when I'm low on gas, but you're right - thats the only time its done it - good point. Will the dealer do anything to fix this? Fortunately, mine's still under warranty and I'd like to take advantage of that. Exigent - keep us updated if you find a way to fix it.

Bryan

[Tubaboy]

Try putting back in your stock chip and see if that solves the problem.

You have so many mods, that can help cause this problem, I doubt that Mercury will want to look at it under warranty.

*shrug*

Paul