Hey all, I dont know if this is the right forum to ask, but I didnt find another one. Here we go. We just picked up our 71 Riviera a few days ago. And no we noticed the engine, a stock 455-4, sometimes still runs a short time when the ignition is switched off. What can this be? Thank you Juergen S
Check idle speed , timing , points and dwell before timing check , and be sure dashpot is adjusted to specs . Sounds like a little tune up and off ya go ..........:3gears: Have fun !:laugh: :TU:
Ok, thanks for the fast reply, but I am a beginner with the tune ups. Can you help me a little? Its my first time. What are the specs for a 1971 Riviera with the 455-4 engine? I guess Ill buy a timing gun tomorrow. Thanks Juergen S
engine run-on This can be caused by several things -possibilities include Idle speed too high Too much timing advance Vacuum leak, excessively lean mixture Poor fuel quality (low octane) Excessive carbon buildup in combustion chambers You should start by adjusting all of the normal tune up parameters to the stock values. Start with point dwell, then set initial timing advance. Then set idle mixture and speed. Make sure that you are using a good quality fuel, try a tank of unleaded premium if everything else checks out and you still have problems. Happy motoring!
Ran into this problem myself, had an electric fan on it... wired it up to an ignition power source... when the shut the car off... the fan spinning would just create enough juice to run the ignition for a few seconds after you would turn the key. Just a thought, ANDY
Hi Juergen, It's look like you have exessive carbon build-up in your engine, this can cause detonation and so engine damage. The carbon glows and ignite the fuel, and so your engine runs for about 1-2 seconds after you shut off the engine. I think there are some liquids which can clean the combustion chambers. Try at your local car parts shop.. Here I have the standard tune-up specifications for your '71 455 Buick: Initial timing: 4 degrees BTDC (set at idle with distributor vacuum advance hose disconnected and plugged) Distributor point gap: 0.016" Dwell: 30 degrees (+/- 2 degrees) Make spark plug: ACDelco R44TS Spark plug gap: 0.030" Idle speed: 600 rpm (airco/klimaanlage aus) If you like, you can do a compression test, the lowest cylinder must be within 75% of the highest cylinder. Good luck!! Bram The Netherlands
Hey...... I'd take her out on the auto-bohn for a good 45 min. high speed test drive. That will blow out the carbon and just may solve your problem.:Smarty: :TU: :3gears: :3gears:
Well, thats exact, what we do to our cars when they have problems with the emission test, but the Riv is a bone stock car, and I guess thats not a good idea to that car. The american cars are build for your highway speed. When you go faster youll get problems with the oil temperature. The car doesnt have an extra oil cooler and transmission fluid cooler. When I drove that car home from the harbour I mostly went between 65 and 75 mph. Engine oil was always between 180 and 200F. When I went up to 85mph for a short time you can watch the temp going up to 220 very fast. I wont drive faster as long as there is no extra cooler in that car Just to be sure! BTW, the car needed 22,5L / 100km (10.45mpg) I guess thats too much, even for that car / engine. I guess 17L / 100km (13,8mpg) should be makeable. Thanks anyways Juergen S
