5.0 Idle issues

[sly]

pressure should be around 35-40psi on the low side. If the switch is cycling above that, yeah, needs to be adjusted lower. Should kick off between 15 and 20psi.

[monotonorobo]

So just jumper the switch and turn the screw until it’s at 35-40 psi? I would have to connect the switch and the connector with a wire then right?

[friskyfrankie]

Are you using an OEM pressure switch designed for R134a or R12? If it is designed for R134a there is no need to adjust anything.

[monotonorobo]

Are you using an OEM pressure switch designed for R134a or R12? If it is designed for R134a there is no need to adjust anything.

I returned the r134 switch that i ordered because it was like 40 dollars so I’m adjusting the OEM r12 one. Before I put it back in I did turn it counter clockwise about 1/4 of a turn like gadget said. I think the previous owner messed w the switch too.

[sly]

try just moving it back to where it was and see if that sorts it.

[monotonorobo]

I put it back in the original position I found it in and it wasn’t as cold as what I set it to beforehand. I’ll mess w it again later.

[friskyfrankie]

IIRC, turning the screw counterclockwise will lower both pressures, while turning it clockwise will raise them. You are just going to have to play with it until you reach an acceptable point. One eight turn counterclockwise lowers the cut out pressure approximately 2 PSI and one quarter lowers the cut out pressure approximately 4 PSI. There are other ways to calibrate the switch but it is probably more trouble than it is worth.

[monotonorobo]

I think I found the sweet spot w the switch. I can’t tell if it’s at its best or not because I returned the vacuum pump but I still have the gauges, and I don’t wanna introduce air into the system. Evaporator has frost build up but it’s not enough to the point where it would freeze over. I think it’s a bit undercharged tho because the passenger side blows wayyy harder than the drivers. I know it’s supposed to be like that because the evaporator is on that side, but it’s pretty weak on drivers side at fan speed 4. But either way it’s performing good enough to the point where it will stay cool in the car

[monotonorobo]

Got it down to 34.1 degrees but I swear I’m not cold enough.. it’s probably because I live in hell. But thanks all for the help again.

[gadget73]

If its at 34 degrees, thats as good as you can ask for. Any colder and its very likely to freeze on the evaporator. If it does that you might actually get liquid back to the compressor and they absolutely do not like that.

[monotonorobo]

Yeah, I had it down a bit lower then went back a 1/4 turn and now it seems it’s doing well. I might go clockwise a bit more just to make sure the compressor isn’t compressing liquid. Any way I can make sure this isnt happening at the position I have it set to now?

[sly]

If you close the the center vents the driver side gets more push. The real problem with these boats is the foam seals for the ducts disintegrate and you lose air behind the dash and freeze your feet instead of cooling the cabin.

[monotonorobo]

Yeah I closed all the vents except drivers side and it found out that’s what it was. I feel like the cabin is so big that’s why it takes a while to cool. I think I’ll probably tint my windows to help it out a bit. I also heard that w the fox bodies the evaporator line where the orifice tube lies is in a bad spot because it’s right beside the exhaust manifold, but maybe because their engine bay is more cramped than ours. I haven’t had any issues with it tho.

[gadget73]

if you get driving along and notice the air stops coming out but the blower is still going, turn it off. That means it got too cold, the evaporator froze, and you're at risk of it eating liquid. If it doesn't freeze over you're probably OK.

the fox cars don't really lay that much closer to the exhaust than a Panther, but the orifice tube us up front basically where our battery sits. The entire run from that point back to the evaporator is cold, and it sucks in heat from the exhaust. The orifice tube is part of the liquid line on those, so either you buy a whole line, or chop it and use a repair kit that is almost guaranteed to leak rather than just replacing a $1 part that sits in the evaporator inlet.

On ours the orifice is much further back so the heat absorption isn't quite as much of a problem. Fox cars also have a smaller condenser so they tend to not convert as well.

[monotonorobo]

Got it. I’ve had it on full blast for hour long rides since I adjusted the switch and I still haven’t came across any problems. Next project will be a repaint but I have a rust spot right under the trim for the vinyl roof. It might be rust under that too but I’ll find out when I do it. And I’ll probably let someone else handle that rust since I’ve never done rust repair.