Reddwarf

My 88 TA sometimes starts in a "mode" there it feels like it's braking hard as soon as I take my foot off the throttle. it only happens if I drive above about 50km/h. As soon is the car slows down it (whatever "it" is) will disengage, and return to normal.

I can usaly make the car behsve again if i just pull over, turn off the engine, wait a minute and turn it back on. (It's a bit of a hit and miss thing, sometimes it works right away, sometimes it's hopeless...)

Any ideas?

Camaro71

TCC not releasing till you break the electric signal by turning off the engine?

Reddwarf

Pulled the error codes today.

I get 25 34 36

25:
"High temperature at manifold air temperature sensor OR Vacuum switching valve circuit open or shorted to ground OR High voltage at ATS sensor"

34:
"Low voltage (high vacuum) at mass air flow sensor (or MAP sensor"

36:
"Burn off at mass air flow sensor OR Problem in transmission shift OR Fault in direct ignition system OR Missing pulses in electronic spark timing signal"

Not shure what to think of it. 36 could be related maybe,?

vorteciroc

By your description alone, it sounds as if some Component is dragging/ hanging-up.

It could be something in the Transmission...
But it could be anything in the Power-Train/ Drive-Line as well.
Not to mention, the Brakes, Wheel-Bearings, Etc...

More Information from further inspection or testing is required to make any progress with even an "Over the Internet/ Ball-Park" Diagnosis.

Good luck!

Reddwarf

Yes, I know. Its not mush to go on. And it's not that easy to describe. But do appreciate both of you for replying 👍.

(But it's definitely in the transmission. It ​​​​​​ feels like a slight downshift when I start to lift my foot of the pedal...)

I was kind o hoping someone would have experienced the exact same thing, but I guess I'm experensing something rare here. 😅

I'm.going to try and fix the MAF errors, and hope it cure the transmission too. I have ordered 2 new MAF relays.

vorteciroc

Lol!


Ya think a Power-Train Engineer wouldn't have experience with that type of thing, lol!


Seriously though, there are MANY overlapping Components in your Transmission that could be the issue.
Thus We (GM) designed the Transmission to easily come out of the Vehicle, and come apart for Internal Inspection and Repair.

Reddwarf

Just in case someone else find this thread, I thought I sum it up.

Replacing the maf burnoff relay seems to have fixed the problem. It cleared my maf related error codes. (I still need to fix error 25 whoever..)

What I think hapend is that since the ecu could sometimes not get correct readings from the maf, it would sometimes not idle when I took ny foot of the throttle. Thuse feeling like braking. It may also have been related to whenever the ac was engaged or not (I'm not shure, and I don't feel like putting the old relay back in to test.... 👀 but it is a theory. ).

vorteciroc

Are you glad now that I told you that it could be a multitude of different things (do not assume it is the Transmission).

Reddwarf

Jupp 😂

i even hooked up.a light bulb on the aldl port for a while so could study the computer signals to the look up while driving.... just so I could rule out that one.... what a mess.... 🙃