1980 Lesabre Sport Coupe questions

[Skip]

Hi everyone, I just bought a sport coupe and had a few dozen questions about it. Do's and Dont's, oil leak fix, possible broken climate control switch, turbo light fix, vacuum leak, spark plug recommendations, etc. I read through past posts, but doesn't address all of my questions. I know there's not a lot of us SC owners out there but if anyone has some time to message/email me, I would appreciate it.
Thanks...Skip

 

[charlief1]

www.beforeblack.net

 

[b4black]

How about posting your questions here? Lots of people to help answer and those that can't will get a chance to learn from the discussions. (Share the knowledge ) The LeSabre SC is 95% the same as the Regal SC, but a little cooler.

The turbo power lights are straight forward. Pull the electrical connectors off the pressure switches, stick a paperclip or wire in them and then ground them to the body. That should turn the light on. If not, the next step is burned out or loose bulbs..

 

[Skip]

Hi, okay here's a couple of questions for now. Did the check of the Turbo lights and the lights work but the vacuum line that comes from the switch and goes to the T is missing the vacuum line that goes toward the passenger side fender is broke off. What is that line and does it effect the lights or anything else?
Also what oil do you suggest? Do I stick with regular or synthetic? the car does have a small oil leak.
And what do you feel are the best plugs for it, NGK, AC, etc??
Thanks for any help.
Skip

 

[b4black]

I'm guessing that the 4" of hose between the T and switch was added on (not stock). I bet someone put the T in to go an aftermarket boost gauge. You could cap it off, or remove the T & line to connect the factory hose to the switch, or add a boost gauge.

Of course anyone has an opinion on oil. I prefer 10W-30 conventional oil. I spent some time in an oil testing lab and concluded the extra money was not worth it. Any modern oil is adequate - it's contamination that is a problem. Water condensation, coolant leaks, fuel from blow by, etc. are worse than oil breaking down. Change it regularly and everything will be fine. I do recommend using an AC Delco PF-52 (or any brand equivalent) oil filter over the PF-47. The PF-52 is a little longer and the same price.

For Spark Plugs, I stick with the regular copper core plugs. AC Delco R44TSX is one heat range colder than stock. Gapped at 0.060 on a near stock engine. No fancy platinum or iridium.

 

[Freddie's Buick]

What is that line and does it effect the lights or anything else?
Also what oil do you suggest? Do I stick with regular or synthetic? the car does have a small oil leak.
And what do you feel are the best plugs for it, NGK, AC, etc??
Thanks for any help. Skip View attachment 220733

That switch may or may not be the vac switch for the non-electronic THM-350 automatic transmission. If the switch isn't functioning you're probably wasting gas, (the clutch won't disengage when braking). It needs a vacuum supply at all times.

I'd stick to DINO oil for now unless you're absolutely sure there are no leaks. Synthetic is so slippery and so good that it will slip into areas were the gasket mating surfaces are weak. Once it does it will induce leakage. It's a good way to track bad gaskets. That's how I seal up my engines. Now I use full synthetic.

As for plugs I've tried them all and I always go back to AC Delco. Don't get me wrong NGK is a very good plug, but I like being able to get what I need quick and not have to shop around. AC's are almost always everywhere and easily available.

 

[Skip]

Hi, thanks again for answering some of my questions. I ran a new vac line from the turbo switch to whatever it was plugged into. But still no lights. Is it the switch itself or it could be the smaller vac line I used, but the car does idle better on start up? Don't know why there was a T in the line, it was a one owner car and there was no boost gauge, it does have a oil pres gauge that lights up but is no longer connected. If it is the switch where can I get one and what is a fair price?
Thanks..Skip

 

[b4black]

If the engine idles better, you likely fixed a vacuum leak. The switch is probaly bad. To tell for sure, you could apply vacuum to it with one of these:
http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html

A GM switch will be hard to find. They have been discontinued for a while. You can buy pressure/vacuum switches from Granger or McMaster Carr. Sometimes they are called a Hobbs switch. It just needs to ground the circuit when the right pressure is achieved. Many are adjustable.

 

[Skip]

I have heard there are two different switches, a 1 plug and (mine) a 2 plug. I bought the Buick service manual but unfortunately it doesn't have the complete vacuum diagram, and I was used to my '87 GN I had. I know there's a purple line and a gray line broke on the pas side, one was connected to a heater hose actuator thing and the other I don't know. A lot of this is all new to me having never had a carbureted turbo before. Just want it running nice (which it pretty much does) and then maybe squeezing a little more power out if it.
But for a 170hp boat it does pretty good on the expressways and goes straight as an arrow and handles surprisingly good. Just seems Buick configured it wrong back then with the gearing, etc. Also I need to replace the weatherstripping and bumper fillers, who carries them or am I better off on eBay?

Thanks again for the help

 

[b4black]

I have the 2 plug switch as well. I believe it is the same switch used on 84/87 GN's with the digital dash.

The purple and grey vacuum lines are part of the HVAC system and that's where you will find them in the shop manual. The grey goes to the heater control valve. The purple goes to the vacuum reservoir can on the fan shroud.

In 1978-80, Buick was after fuel economy. In mid 1981, they started going after performance. Rear gears went to 3.08 on the Regal.

Parts will be tough. I doubt anybody reproduces anything for them. Ebay and NOS parts vendors are the way to go. You should pick up a parts book (or body shop crash book) to look up part numbers yourself.

 

[Skip]

That's cool about the switch, send me a PM and discuss price, etc
Thanks again!

 

[Skip]

Ok new question about the turbo power switch, drove home last night from the city and there wasn't really anybody on interstate so I nailed it to see what she had and when I was approaching 75-80 the first yellow light went on but never went to the red light. Besides replacing the vacuum line and reseating the plug I've done nothing else. Is that nut on the switch an adjustment of some sort? The light has come on 2 other times briefing when I was go up a hill.
Thoughts???

Thanks....Skip

 

[b4black]

It is an adjustment, but they usually don't need to be changed. The yellow light comes on about 4-5 psi. The orange is about 7 psi. It could the switch, the bulb, or you are not making enough boost.

You should get a boost gauge. I like ones the read vacuum and boost. I would mount it in the car, but you could just temporarily hook one up and tape it to the windshield.

If the carb's secondaries don't open up, which is common, then the boost is limited to ~6 psi. A boost gauge is a good diagnostic tool.

 

[Skip]

It felt pretty healthy on the highway, but I'll check the carb, I cleaned it up w Gumout and threw some in the tank. Does have flat spot when your first taking off, still have to tune it up and change some vac lines. Anything else that I should do besides the regular tune up that you'd recommend? As far as the turbo lights I tested them with the paper clip and they both lit up, which way should I adjust the nut on the switch
so I can rule that out as a cause. I just ordered a SW vac/boost gauge so we'll see what it does.

Thanks again!!

 

[Skip]

P.S: not sure how they usually are but she gets very bad gas mileage even when I'm not on it, which is most of the time.