Hello once again, I'm back with another question. My 94 cutlass supreme sl 3.1 auto trans is is feeling like it may only shift 2nd and 3rd. The engine has a miss and loss of power. This is not new , I asked about that before. What I wanted to know is will the tranny have vacuum lines that tell when to shift or if leaking vac could that cause the shifting problem. The car is lugging from a stop ,it feels like it is starting in 2nd gear. Will the tranny cause the motor to have a miss with strong vibration? I know these are dumb questions , but I have no place to find out answers for them. Also do any of you know where I can get a engine compartment layout picture with the different parts marked and named. Will the 94 have MAF or MAP sensor? Thanks for taking time to read and answer any questions. gary r

Is that the 'T' or 'M' engine. Eighth character of VIN.
Both use a MAP sensor to determine engine load, no MAF. The module does look at load to determine shift points. We always want to have an engine that'* running properly before diagnosing this kind of problem.

If you (1) don't have a tachometer and (2) at the same time the engine has other issues and (3) you don't have a lot of experience diagnosing this kind of thing then there isn't an easy way to diagnose from here. What I would suggest is that you fix the things you know you need to fix.

Also, if it is missing etc. that badly, you may have to give it enough throttle to do its job that it doesn't want to shift to the next gear.

A Chilton or Haynes manual would be a good start. They also explain things fairly well if you're a beginner.

Carfixer and Caerdalcub, thanks fore the info. I will keep plugging away. Not ready to give up yet. I have worked with tools my whole life. I'm not a stranger to cars, but most of my time was before computers ran the car. I prefer a rear wheel drive anyway I also had 4 VW vans at different times and kept them on the road. A 52 , 58 ,60 and 62 kombi. Thanks to you 2 I have some basic things to look at and will let you know the outcome. Thank you. garyr

Let me know what engine it'* fitted with and I can get you most any diagrams and flow charts you might need.

Ah, okay that will help.

Put it in [Drive], get it up to 45MPH, click it down a gear. Did you feel it shift down?

While I'm thinking about it: Does it have a tachometer?

Sorry it has taken so long to get back to you. The car vin has M in the 8th place and there is a tach in the car. We have a bunch of rain and with the holidays I have not had any time. Hopefully this next week I can put more time into the car. Thank you all for taking time to read and answer my questions,. gary r

We got some of that same rain here in Tucson. An inch in half a day.

Let me know if you need any info.

Carfixer, thank you and I will do a drive test tomorrow . I'll let you know what I find.
Mike I hear there is more on the way. Damn I sold my boat. lol