Abear

iTrader: (1)

I have no Idea whats goin on. It started..Saturday morning when I left for the dyno. I was bringing my sister to get her rental car and when I got in the car and started it up and shifted to reverse, the car went into reverse hard. At first I figured it was just cuz it was cold because it did it again when I shifted to drive.
When I got to the dyno, I was moving my car to get it ready to get on the dyno, and the car started studdering like it was running out of gas. Course the gas tank was nearly full. The dyno guys turned the car off and let it sit for 5 minutes and then tried it again and everything was normal. On my way back to my house today, I had the car on cruise control and I was going about 65 and it started studdering again..cruisin at 65. I have no Idea whats goin on, the only thing is the CELs on and its an O2 sensor, and of course I just installed the SAFC2. But Ive had the SAFC2 on since Friday morning and nothing was wrong all Friday. The only thing that changed between Friday and Saturday was that it was below 40 degrees Friday night. It has been really cold like that the past few nights.
At first I just figured it was the that the car just needed to warm up, but that therory was disproven today driving home since it studdered at 65.
Does any know whats up?

Kaiser

iTrader: (1)

I'm speculating on a similar problem I'm having. I think I've concluded that the heater element in my O2 is shot. If the car is cold I have trouble getting up to 3800 rpms where it goes into open loop, then it takes of like a shot. If I've been into boost, the sensor heats up and the car drives normally at lower rpms. Does yours follow this pattern? Aside from the boost.

Abear

iTrader: (1)

Not really. Its not so much I have trouble getting to a certain RPM, its just the transmission shifts pretty hard. Not like a Lexus should. Then, Im not sure if its the tranny, or the bad O2 sensor, but the car pretends like its running out of gas, but when I give it more gas, it stops. Then, if I go back to cruising around 70, it does it again.

Kaiser

iTrader: (1)

Sounds like the same problem that Xeeeem is having. Check for his post. Have you checked the trans fluid yet?

Abear

iTrader: (1)

Not yet. The car needs to warm up before I check it right?

Kaiser

iTrader: (1)

The car needs to be at full operating temperature and the motor needs to be running while you check it.

Abear

iTrader: (1)

Ok, so I went ride around to get the car to operating temps and when I got home I checked the trans fluid. It was about an inch more than hot, I dont know if thats good or bad. After the car got warmed up I punched it to get infront of a truck pulling a car and at 100% throttle the car was barely doing anything, def. not 100%. I dont know if thats a transmission problem or if its something else.
So I get back home and I finished checking the fluid and I go to close my hood, and of course my hood shocks dont work anymore so the hood just slams. When it slams, the car starts to studder. It never dies out, but its like it wants to. I dont know what to do, I have to go home to Houston next week and Im scared to drive it for 4-5 hours.

Also: Its been about 4000 miles since the oil was changed but I usually go about 1000 over before I even notice it needs changing. So its nothing new. But do you think because of the cold weather and the oil needing to be changed that thats whats causing the studdering?

Kaiser

iTrader: (1)

Got the answer for you! Go out let your car idle and knock on the mass air meter. My bet is that it stumbles. Your Karmen is shot. I have a spare in my garage if I'm right.

Abear

iTrader: (1)

Well my cars a 96. So its hotwire. I have a MAF from a 96 TT supra, so its a little bigger. I will go check the MAF.
That may solve the studder problem, but I dont think thats whats causing the transmission to act the way it is.

Abear

iTrader: (1)

Its back to idle, and Ive been shaking the MAF like crazy, its not doin it, and now when the hood slams, its not doing it either.
It crazy.

Kaiser

iTrader: (1)

I had a 4runner with a loose wire in the maf. I had to repin it. Kinda reminds me of that. The only things that come to mind that would make it shudder like that with the hood closing is a bad maf or an intermitten short. You guys and your fancy 96 models.

Abear

iTrader: (1)

Well, I just took a little "run through the country" and everything is working fine. I wish somethin would just reveal itself. Course not its about 60-65 degrees outside were as its been pretty cool the last few days. I will see if happens after the car sits for a few hours.

Just to be clear, the MAF on my car is stock. I have a Supra TT MAF, but its not on the car.

Epik

iTrader: (7)

what about the "AFL" display on your SAFC? is it reading a % that increases when you stomp on it?

Have you changed the fuel filter recently? Possibly a plugged pre-cat? Had that one happen on me.. how is the exhaust flow out the end of the pipe?

Abear

iTrader: (1)

The AFL was going up to about 50% when I would stomp on it, havent had it on since after the dyno. After I eat Ill go for another drive and look at the AFL. Fuel filter hasnt been changed in a while, I thought thats what it could be too. Ive been meaning to change it since I heard about what ethanol does to the gas. Exhaust flow is same as always.

Abear

iTrader: (1)

Just got back from a nice little drive. I have no idea whats goin on, the car is just pissin me off so much. Earlier it was running fine, and now its doing the same thing it was doing last night. What would cause it to act normal, and then act stupid just because it sat for a little while. Anyway, I made some videos of the SAFC2 to show whats goin on. I punch it and at full throttle it wont shift down. I also took it to show Epik the AFL.

Time for some videos. In this first one, the damn thing goes from 1900 RPMs to 2800 RPMs in almost 20 seconds.
http://www.youtube.com/watch?v=Qoo0_Hm5-Ic
In this one, I do the same thing, but this time with the O/D off. Not much difference, but it does rise a little faster.
http://www.youtube.com/watch?v=diL2sZ83WFs
In this last one, this is me just revving, not full throttle, but it revs normal so does that kinda rule out the fuel system?
http://www.youtube.com/watch?v=diL2sZ83WFs