95 Transsport 3.8L CEL ON - No OD - No cruise control


WelmoedJ
03-08-2008, 03:02 PM
My (European) Pontiac Transsport served me rather well over 211k Kms, but now shows the CE light (it needs service, I know). It turned out that cruise control also is no longer working, OD is no longer selected, but all other gears shift problemless forth and back, and that kickdown refuses to shift back.
Though the engine starts well, runs fine and normal accelleration seems almost as before, the lack of kickdown is felt when swift accelleration is needed. Moreover since OD does not work, the RPM now is much higher.
In one or two occasions I had the feeling that while driving the gear box disengaged from the engine and after taking the foot of the accellerator and then slowly depressing it again, it came back "on line". My son found while slowing down at a traffic light that at the stop, the engine killed itself.

I have checked fuses, which all are OK. I have not checked the CBs behind the passenger foot well cover. In the Haynes manual a fuse for the cruise control is mentioned, but I can't determine its location.

Having gone over all relevant messages I come to the conclusion that at least the TCC is no working as intended or is stuck. There could be more not working properly, but to be sure a code reader is needed and I do not have one.

Before going to seek (expensive) help at a shop, I hope someone on the forum will confirm my findings and point me in the direction where to start (disconnecting TCC?), CC fuse?

Thanks,
Welmoed.

LMP
03-08-2008, 06:48 PM
MOst probably a Throttle Position Sensor code.
TPS failure inhibits cruise, TCC and 4th gear, and will cause misses and jerks. ALl your symptoms coincide.
CHeck that first. http://www.avigex.ca/xport/maflocation.jpg
www.avigex.ca/xport/dtc21.jpg
www.avigex.ca/xport/dtc22.jpg
http://i250.photobucket.com/albums/gg246/avigex/TPSphoto.jpg
code numbers are different in '95 but equivalent to those above.

WelmoedJ
03-10-2008, 03:28 AM
MOst probably a Throttle Position Sensor code.
TPS failure inhibits cruise, TCC and 4th gear, and will cause misses and jerks. ALl your symptoms coincide.

Thanks LMP,
I will look into it starting with the suggested TPS.
When done I will report back.

WelmoedJ
03-22-2008, 07:30 AM
Most probably a Throttle Position Sensor code.
TPS failure inhibits cruise, TCC and 4th gear, and will cause misses and jerks. ALl your symptoms coincide.

Thanks, LMP.
You were right on the dot! I tested the TPS and found that the voltage remained steady at 4.91V. The Ohms testing resulted in zero Ohms. No difference while operating the throttle range in both tests.
So I have to replace the TPS.

BTW: very nice classic car, that Graham-Paige. Must be a lot of work to keep it going.

Welmoed.

WelmoedJ
04-28-2008, 08:05 AM
Have made the repairs. Car runs as intended again.
Thanks for your excellent diagnosis and help.

BTW: do you have info on the fuel pump/sender unit?
Need to know its actual size (all measurements) and pressure info.

LMP
04-28-2008, 08:48 AM
Pressure on my gauge is 38-45 psi
www.avigex.ca/xport/fuelpressuretest.jpg
www.avigex.ca/xport/fuelpressuregauge.jpg (made from a/c recharge unit)
NO absolute dimensions for the fuel unit..but will scan picture in manual and update later.

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