only a few issues
Thread Starter
Heel & Toe
Joined: Oct 2015
Posts: 15
Likes: 0
only a few issues
Hi all recently picked up an 1984 l83 vette. Heater works but sometimes only blows cold air? Picked up a new tps as the old one was shot and plan on cleaning IAC as well. Have an idea on how to set tps but there is suppose to be a screw to adjust idle. Is that behind the tps? Car is hard to start when cold and will idle to like 2k then settle to 1k idle. I don't think it's the temp sensor so that leads me to cleaning IAC sensors and replacing tps. Could the heating issue be a cracked heater core? No smell. Sorry if u have heard this before just new to a c4 and could not find answers. Thatnks to all who reply.
Last edited by darthvett; Oct 9, 2015 at 07:00 PM. Reason: more info
Melting Slicks
Joined: Nov 2013
Posts: 3,451
Likes: 336
From: Greater Cincinnati Area.
I don't know if this is the problem, and I don't have an 84, but I hear the heater control valve is a problem on our year C4's.
If it sticks? I would assume that could cause cold air only. On my car (85) it's on the passenger's side of the engine compartment, by the firewall, where the hoses enter.
If it sticks? I would assume that could cause cold air only. On my car (85) it's on the passenger's side of the engine compartment, by the firewall, where the hoses enter.
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Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
Not sure about the digital HVAC controls but my manual '85 heater control valve is operated by vacuum. The valve is on the RH side and is an assembly of a control valve with metal tubes running from the firewall forward into rubber hoses. This valve will get sticky as well as having issues with the vacuum supply line. Find the valve and follow the vac lines looking for cracked or damaged lines. They are 30 years old. Have someone move the controls in the cab and watch the valve for movement. The highly expensive Corvette valve can be replaced by a mid 80s full size (with gauge package) Chevy valve after extending the rubber hoses. I did this and it works flawlessly at 1/4 the price. Search for the part number.
Good luck!
Good luck!
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You might have a problem with the temperature blend door. It determines the temperature of the air coming out of the air ducts. It is controlled by the COLD - HOT lever with a cable. Check that out.
Racer
Joined: Sep 2003
Posts: 364
Likes: 15
From: Monmouth Maine
1st Congratulations on your "new to you" 84 Corvette and Welcome to this Forum!
It would be a good idea to get a Factory Service Manual (FSM). That would help you tremendously!
I also agree with DinoBob to do a search. You may find these issues have been discussed several times and it would be good reading anyway. There are always hints associated with responses. When that's suggested, we certainly don't mean to "pass the buck"...there's a lot in here.
Chuck M
It would be a good idea to get a Factory Service Manual (FSM). That would help you tremendously!
I also agree with DinoBob to do a search. You may find these issues have been discussed several times and it would be good reading anyway. There are always hints associated with responses. When that's suggested, we certainly don't mean to "pass the buck"...there's a lot in here.
Chuck M
Last edited by hotmotorsports; Oct 11, 2015 at 09:23 AM.