91ZLS1

OK, this is the list I have replaced and still no heat... Water pump, thermo, heater control valve, heater core, I also have NO leaks or air bubbles either. What is the deal with my heat? The vaccume line coming off of the heater control valve has to be plugged with a bolt in order for my heat to get luke warm, but it still doesn't get hot. If I put the vaccume line on the heater control valve where it is sopposed to go, my heat goes from luke warm to cold. Does this sound like a broken vaccume line or bad heater controls in the dash?? My blower is working and it works on every position and all the vents work too. The heater blend door is working also, I've checked. I've also checked the heater core hoses and they are both hot to the touch, so WTF is going on. What does that vaccume line coming off the heater control valve have to do with my heat??
Thanks
Kyle

EYEROCK89

Are you running a 160 degree thermostat in your car? The cool engine temp in some cases will cause you to have very little heat in your heating system.

Sitting Bull

You will need at least a 185* thermostadt and perhaps a new rad cap. Rad caps cause more cold heater problems ...

Vader

I only live about 30 minutes from '91 (15 in an Impala), and I can assure you that a 180°F is adequate around here. Anything less is a stretch, however. And of course, that 180° is the opening temperature, so typical operating temperature is about 185-190°F.

Coupled with the other problems you are experiencing, you may have a vacuum routing problem, or perhaps even a low vacuum condition, which might partially explain your DTC 32 and exhaust popping.

91ZLS1

I have the stock 195* thermostat in there. It is installed correctly also.

Vader, Did i read that right, you only live 30 min away from me??

Anyway I'll go out and purchase a new radiator cap and see if that helps the heat thing, but I still don't understand why that vaccume line has to be blocked in order to get some warm air.
Where could i find a vaccume hose diagram for my 91 305 TPI, I don't have the sticker under the hood no more. And how can I test vaccume pressure? Vader, sounds like you really know your stuff, I appreciate the help from everyone, thanks.

Vader

O.K. That's a bit of a stretch if you drive the legal speed on 43 (which is HIGHLY advised, since they watch it so closely). I can push it and make Delevan in about ½ hour, but not Lake Geneva.

Aftter considering it some more, it's also possible that your EGR is leaking, causing not only the '32' and running problems, but low vacuum as well. Have you taken a vacuum reading at idle?

91ZLS1

Vader,
I haven't taken a vaccume reading at idle. Where would i get a tester at and then what vaccume line would I test? Are all the vaccume lines sopposed to be the same amount of vaccume?? Once again sorry for all of the questions.
Thanks