78 turbo lesabre

[Dirtexpo]

more power

I just want the power. I put a lot of money into this car , but I'm not getting the proformance I expect out of this turbo. I don't know were I'm going wrong, but I need help. I'm not feeling power. With cam, pistons, rods and having the engine done 30 over, turbo rebuilt ( factory turbo) , and rear end 373 I should feel a major differance by now. Do I need a bigger turbo? Could it be the vac lines are not connected right, because they did have problems connecting the vac lines after the rebuild. And the mech. told me that the vac. line diagram that I got off the net. was incorrect. The one on the net showed one line going to the wastegate, but the turbo that was on the car had two. Do I need trans work ( The mech. said a turbo 350 trans was already in the car so I never had it worked on, it might have been in there since the car was bought.) My next step was to put the 2.5 pipes on, but I don't what to spend the money if its not going to solve my problem.

 

[b4black]

DO YOU HAVE A BOOST GAUGE and if so, how much boost are you running? You'll never have a fast car with low boost.

Before you said the actuator had one line, now it has two? I expalined the two lines above. The vacuum diagram won't show both lines to the wastegate actuator, becuase only one is vacuum, the other is part of the boost circuit. The vacuum line diagram you got off the net (linked above) is right. It comes right from Buick.

As far as the trans, a higher stall converter might help, but again, I suggest getting it running right first.

I would tell you that the 2" pipes aren't a problem, because after the cat, the downpipe is the next restriction, but I would be repeating myslef.

You already have the answers, you need to apply them. Without a boost gauge, your hunting with your eyes closed.

 

[Dirtexpo]

turbo lesabre going wrong

Yes, you are right. The wastegate does have one, I think the turbo had the mystery line. As you guys can see I don't know much about this, but I need help. I was driving the car to the shop today it felt like it was hesitating. When I took it to get the oil change they spotted an oil pan and I'm not sure, but I think he said Main seal or something like that. I'm almost positive that I should be getting more power. AND WHAT ABOUT THE BIGGER TUBRO? WHAT ABOUT THE TRANS.

 

[b4black]

It's odd that it only has one line/port. 95% have two. There are some one port wastegate actuators that use one line and are normally open (NO) instead of normally closed (NC). They use vacuum to hold them shut and do not have a pressure line. I suggest tracing the one line and see if it connects before (vacuum) or after the turbo's compressor housing (boost). (the normally open units were a one year experiment that produce more lag/less power.) I would also unhook the line, apply pressure and vacuum to it and see what it does. A NC will push out with boost and a NO will suck in with vacuum. This will also confirm that it isn't blown.

The hesitation could be many things, but did you fix the disconnected THERMAC hose? (If not, re-read the post about it above) It's been very cold in Michigan lately.

Bigger turbo? Nobody makes one, but larger impellers can be installed after machining the housings. It would be much easier to up the boost on the tirbo you have first.

Yes, you should have a 350 trans.

I'm almost positive that I should be getting more power

If you would just install a cheap boost gauge, you would know exactly what's going on. If you install a combination vacuum/boost (30/20) gauge it would help diagnosis any vacuum leaks too. These cars are all about tuning. You need gauges to tune!

 

[Silver 6]

I have a 79 LeSabre Sport Coupe and this is something I will face next spring. I believe the LeSabre and Regal Sport Coupes were intended to be smooth cruisers and the Century Sport Coupe was intended to be the Hot Rod. It was the Century to first get the dual exhaust from the cat back and it came with a firmer suspension.

The early turbos came with a loose 82 exhaust turbine. These need flow to produce boost and would tend to most come in when you were in situtations like kicking into passing gear. It is also quite possible that your TH350 has a low stall torque converter in it. This would have been in place to improve mileage.

With a loose turbo and a tight converter the motor will not produce much added power off the line. The 3.73 gears you added will just let you better use the power you have.

I intend to add an 82/83 turbo with the tighter 63 exhaust turbine and strange as it sounds, a TH200 to replace the TH350. I chose the TH200 over the TH200R4 because of seveal things. The TH200 has the lower first gear of the TH200R4 used in the later turbo Regals and will use a 2000-2200 stall converter with a lock-up. It is lighter and it bolts in with only a change of kick-down to TV cable. My car has the 2.73 rear gears and with overdrive these would be too high. I will have Lonnie Diers build the transmission and there are parts to upgrade it like the overdrive.

 

[Dirtexpo]

Dying Out

78 Turbo lesabre, My only problem is hesitation. When I step on the gas its a pause ( hesitation , but not like a regular hesitation ) the car just stops no sound , no acceleration , no putting , no nothing BUT, it won't cut off . It would cut off if I continue to mash the gas pedal to the floor until I cuts off. But if I don't do that it will hesitate and start back again. My mech. told me to change the fuel filter but, he doesn't know for sure if thats the problem Or could it be a carb. problem or adjustment?

 

[b4black]

Re: slow take off

Have you fixed this yet?

Originally posted by Dirtexpo
The hose coming from the air cleaner tank to the lower driver side of the motor is not connected. Could that be the problem and what does it do?

THERMOSTATIC AIR CLEANER (THERMAC) - The air cleaner is design to provide an incoming air temperature of about 115 degrees (F). A temperature sensor is in the carburetor elbow and is used to control a vacuum actuated damper door in the snorkel of the air box. This door on the snorkel blends incoming air with air heated by the right side exhaust manifold, via a very narrow duct. This improves winter weather driveability. Warmer climate and summer only driven vehicles can do without thus system. During WOT acceleration, the (carburetor) vacuum drops to zero and the door will slowly open to allow unblended air through the snorkel alone. There is an inline delay valve which could be remove for quicker opening of the damper door.

Originally posted by b4black
Without the tubing, the THERMAC has no source of heated air. Make sure the damper door is working. Make sure there is a place on the manifold to connect the hose. There should be a heat shield (stove) over the manifold. The tubing is available at most auto parts stores (you may need to use two short ones).

You may want to re-read this entire post. You're going in circles.

 

[Freddie's Buick]

Get rid of your mechanic....

 

[Dirtexpo]

78 lesabre sport coupe

I've think I've got it. There was a vac line disconnected on the carb. That was the problem. I still changed the fuel filter. No more hesitation. The next step is the timing. I think its a little off.