Questions
Thread Starter
Instructor
Joined: Feb 2011
Posts: 116
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From: Griffith Indiana
Questions
Ok guys/Gals;
I have a 1980 Corvette L48 that has been sitting in a driveway in Northwest Indiana for two years from prior owner. I bought the car and am attempting to restore it to working condition. My questions are below:
1. I have all the interior and dash out of vehicle. When I start the car, it does not want to stay running and requires a 2nd or 3rd start before it will idle....and it idles terribly. I know that earlier model vehicles worked off of vacuum....Since I have the dash out, am i affecting idle or motor performance possibly because a vacuum line is disconnected from dash??
2. The drivers side exhaust manifold is cracked near the flange. Only two bolts holding manifold to exhaust pipe, can that cause rough idle and performance issue as well?
3. Car has been sitting for 2 full years, what mechanically should be looked at and possibly replaced? I know these would be suggestions, but want opinions from you all on what should be assessed.
Thanks.
TTERZ
I have a 1980 Corvette L48 that has been sitting in a driveway in Northwest Indiana for two years from prior owner. I bought the car and am attempting to restore it to working condition. My questions are below:
1. I have all the interior and dash out of vehicle. When I start the car, it does not want to stay running and requires a 2nd or 3rd start before it will idle....and it idles terribly. I know that earlier model vehicles worked off of vacuum....Since I have the dash out, am i affecting idle or motor performance possibly because a vacuum line is disconnected from dash??
2. The drivers side exhaust manifold is cracked near the flange. Only two bolts holding manifold to exhaust pipe, can that cause rough idle and performance issue as well?
3. Car has been sitting for 2 full years, what mechanically should be looked at and possibly replaced? I know these would be suggestions, but want opinions from you all on what should be assessed.
Thanks.
TTERZ
Pro
Joined: Sep 2010
Posts: 745
Likes: 66
From: Hutto Texas
If you have the dash out and the headlight switch is not hooked up or the HL over ride switch is disconnected then you have a vac. leak which would cause high or rough idle. I had the full dash out of my '81 but I was still able to drive it with no problems.
Having a cracked manifold I believe is a bigger problem as it has many adverse effects on engine performance. Since the car has been sitting for 2 years, I bet money the carb is gummed up and probably has leaks internally. My trouble shooting list is below.
1. check interior vac. leaks
2. check ignition timing, plugs, wires, etc.
3. rebuild or replace carb with known working unit
4. repair or replace exhaust manifold
Having a cracked manifold I believe is a bigger problem as it has many adverse effects on engine performance. Since the car has been sitting for 2 years, I bet money the carb is gummed up and probably has leaks internally. My trouble shooting list is below.
1. check interior vac. leaks
2. check ignition timing, plugs, wires, etc.
3. rebuild or replace carb with known working unit
4. repair or replace exhaust manifold
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
There are two vacuum lines that enter the cabin- one for the headlights and one for the HVAC. Remove and plug at the vacuum source on the inlet manifold to see if idle improves.
A cracked exhaust manifold shouldn't make much difference at idle except a lot of noise.
A cracked exhaust manifold shouldn't make much difference at idle except a lot of noise.
Safety Car
Joined: Sep 2005
Posts: 4,064
Likes: 104
From: Southeast, Tennessee
St. Jude Donor '09 thru '26
anything that has been sitting unused for 2 years will need many of the moving parts overhauled. the brake calipers should be removed and service to insure they function properly, in addition as mentioned above all fluids (including the gas in the tank (what's left of it that hasn't turned to shellac). there's a good chance in addition to the wires, plugs, etc if you were trying to run it off the gas in the tank or if you just added to the tank, you are pumping all types of crap up into the fuel pump and the carb. where i live if you leave a car unused outside for as little as a couple of months, the car will start growing stuff you don't even want to consider thinking about, lol.
the cracked manifold isn't causing you the problems you describe. it needs to be addressed eventually, but it isn't what is making the engine run rough.
the cracked manifold isn't causing you the problems you describe. it needs to be addressed eventually, but it isn't what is making the engine run rough.
