Aboutautohelp Expertise On hands professional expertise in all aspects of Cadillac diagnostics and repair mid 1970`s thru 2000 year vehicles. GM certified in electronic fuel injection, Automatic transmission, Heating and A/C, and onboard vehicle computer diagnostics.
Experience Held over 15 GM certifications prior to retirement in 1989.
Organizations Prior to retirement held several ASE certifications, numerous Factory certifications.
Question I have a 94 Deville 4.9 with now 201k miles on it - still runs great but recently I got the following problem.
After shifting in the highest gear (at about 45-55mph) and I accelerate it does not do it properly - then it shifts one gear back (higher rpm) and it works smoothly.
I only have this problem when it engine is warm.
New spark plugs, wires, air filter,...
Your help is greatly appreciated!!!
Wolf
sales@godspeednet.com
www.godspeednet.com
Answer At 45 to 55 mph's the transmission shifts into overdrive and any acceleration such as going up a hill, The overdrive will kick out and you will drop to the next lower gear.
Try this and tell me if it is working properly:
Maintain your speed at all times at 55 mph's and with the AC OFF, use your left foot and slowly start applying the brake pedal with your left foot and feel for a slight bump in the car along with a tachometer drop of about 200. Do NOT increase or decrease the gas peddle and slowly take your foot off of the brake pedal and you should feel another slight bump in the car with an increase of 200 on the tachometer.
