wardie

Hi Everybody I'm new to the forum and new to Corvette ownership. After 44 years of marriage, 3 sons, 5 grandchildren I finally decided that I was going to buy a Corvette...something that I truly always have wanted. I purchased a decent 1984 with 114,000 miles. It has the Doug Nash 4+3 transmission.

The gauge cluster has been rebuilt and works perfectly and just about everything except the AC works as it should.

I have two questions. The car starts and runs fine but after warming up if I let it the car will vary it's idle and eventually stall out. I found a vaccuum leak from an open Tee and plugged it. Oh BTW the car has updated roller rockers. My friend said to mention this? When I was test driving there was no idle problem?

The second question is the overdrive. The PO said wait till engine warmed up before engaging OD. On my way home from the Ygi Bair Car Show I had an opportunity to run her up to 75mph and engage the overdrive. The Overdrive dash light illuminated and the OD kicked in perfectly. After about a minute it just disengaged and would not re-engage until I was almost home about 30 miles then I hit the switch and it engaged.

I looked over the car before buying and reviewed the information here. The car is a decent purchase..for me a dream realized late in life but one that I can enjoy for hopefully several years. Thanks for any help that cn be shared. Wardie

billschroeder5842

Welcome to the Forum and congrats on your dream car!

The L83 engine needs a bit of love and it will be a beast. As you found, it is VERY sensitive to vacuum leaks. You probably corrected your stalling by plugging the Tee, however you may want to trace it and fix it according to specs or you may have other vacuum rated things pop up. Buy a vacuum gauge; it will be one of the most valuable tools you have.

Also become familiar with your TPS, IAC and coolant sensors. If you fix your vacuum leaks and bring into spec those sensors, you will have dialed in most of your engine.

Tom400CFI

W/o knowing what "T" you plugged and what it's function is...I'd put it to factory specs rather than simply plug things.

As for your OD, I'd start by doing a fluid and filter change on it. In fact, a car new-to-you, I'd change ALL the fluids filters.

JoBy

Did the OD lamp turn off at the same time?

OD-lamp is wired together with the OD solenoid and is controlled by the ECM. If no OD light then ECM is not commanding OD or relay is bad. You can force OD by applying 12V to the F pin on the ALDL connector.

You should connect a scanner to figure out what the ECM is doing.

http://winaldl.joby.se/

wardie

JoBy
The Red Overdrive lamp was on when the overdrive was engaged and was off when the overdrive dropped out.


It went back on some 30 miles later when I pushed the Overdrive switch.And off when I pushed thwe Off side of the switch.