Mnemonic1

I had recently bought a 84 vette with 69k on it.... car is in good condition. but here is a list of whats wrong with it that i dont know what to do with:

1: Stalls Occasionally... only when i rev it too high or hit the gass and suddenly let go when in drive or park.
2:Idles Wierd..... goes from 690rpm to 750rpm CONSTANTLY... im thinking a possible misfire
3:NO HEAT!?!?! A/C works but when i throw it on heat its just semi cool air... WTF!?
4: when the motor is cool, and i hit the gas, it sounds like the engine is just goes down to idle rpm and about 5 secs later jumps and takes off.

Anyone have any ideas for me ? hopefully a somewhat inexpensive way to get around this?
-Dan Cooper

Mark 84ltblu

Dan:
The first thing I did when I got my 84 was replace the coil, plugs, plug wires, distributor cap & rotor. I was having most of the ignition symptoms you are describing and a major tune up cured them. It sounds to me like you could have a failed heater core as well.

CAPN17

The complete tune up is an execellent suggestion, also replace the fuel filter located under the car on the passenger side. Check the hoses and valves involved in the air and heat controls inside the car as well as the heat divertor valve located under the hood on the passengers side right near the heater box. It has water hoses running into it and a plastic (skinny) hose to the top of it. When it functions properly it diverts the heated water around the and out of the heater core. This prevents cold air from the AC being mixed with heater air from the heater core.

HWoods

Most importantly being it is an 84 Vette (Cross Fire Car) find your way to http://www.crossfire.homeip.net The Cross Fire Vault, lots of info on Cross Fire Car

vinny85

Mnemonic1,
Don't know if I'm on the right track, but my first guesses would be:
Prob's 1 and 4: fuel filter or fuel pump. I would try replacing the fuel filter (cheap and a good idea anyway). If not that, you want to check and make sure that your fuel pump is providing enough pressure (i.e. can't keep up when you mash on the gas).
Prob 2: I had a similar problem on my 85 when I first got it. Idled erratically between 450 and 750. Check all your vacuum lines for a leak. Mine ended up being the PCV hose had come unhooked. Put it back on--no probs.
Prob 3: Maybe your heater core is shot or it could be disconnected. If the heater core fails, it is usually easy to notice due to the large amounts of coolant either on the floorboards or under the car, depending on the reason for failure. A lot of times people will just disconnect the inlet and outlet hoses and splice them together (thus effectively removing the heater core from your cooling system). This is a quick and dirty fix to get the car back on the road to avoid the labor intensive job of replacing the core. You can check this by looking at the firewall from underneath the car and checking to see if there are two fittings that look like there should be coolant hoses connected.
Just my $.02. Hopefully some of it helps
Phil


[Modified by vinny85, 4:03 AM 9/14/2001]

Ken Hakken

I bought my 84 with 93,000.
Your Ignition problems:
I had many of the same symptoms you have.
I replaced the ignition with an acel high energy. It helped some but I still had your idle symptoms. I replaced the idle air valves. All the time noticing slight improvement. I uses AC rapid fire plugs. Changing the fuel filter will help. But the biggest improvement cam when I changed the timing chain. A worn timing chain will put the valves and distributor out of sequence with the pistons. And it depends on if you are accelerating or de-accelerating the timing can retard or advance and even oscillate. I was also fowling number 7 cylinder plug every 4500 miles. After I replaced the timing chain all the other work I had done paid off. It even stopped my plug from fowling. My 84 has 118,000 miles on it now and runs like a tiger. Also I recommend Mobil 1 5w30 oil. Every week since I started using it I can feel some improvement. The engine just keeps running better and better. Also I stopped burning oil. After 1600 miles I'm still on the full mark.

Your Heater Problem:
Your heater problem is the heater bypass valve. Ecklers sells it for about $90. I had to change mine because it had a coolant leak out the packing.

I love my 84. I bought aluminum valve covers from ecklers and refinished the magnisum air cleaner assembly. My biggest problems were with the air conditioner but I have that working perfect now. I converted it to R134A. I'm on my forth compressor since I bought the car. Mostly it was the clutch breaking off at the pully. There is a tight spec on the gap and you have to adjust it otherwise it will slip when on or rub when off. This causes the pulley to over heat which causes the clutch pulley to break off.

Good Luck :chevy