Buick V6 Turbo cuts out at high boost ?

[buickman1980]

I recently purchased a a 1977 Triumph TR7 with a Buick V6 Turbo Conversion. I believe the engine to be out of a 1980 Regal. I'm running a T50 tranny as well. The car also has a 4 barrel Rochester Quadrajet carb. Here's my issue. The car idles erratically from 500-1500 rpms at will. No matter where
I do set the idle in the beginning,but it still does this. Now my biggest issue : When the car is idling, the Boost gauge shows a 20 on the left side if the gauge. When I accelerate at
full throttle in any gear, the boost hits 5-10 and the car cuts out until I let of the gas at least halfway. If I do this, the boost
stays around 10 and functions fine. I can hear the trubo whine like normal, but the problem is driving me crazy. Is there a Buick
Turbo Nut out there that can help me ????
Also, could you tell me the HP of this engine ?,and if the gauge should read on the left side when Idling. Thanks in advance. Ryan / Denver, CO
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[Buick From Hell]

Buickman, I'm going to also place this in the "before black" tech section, since that's the pre-1984 turbo regal tech section! You may get more answers there!

Kevin

 

[Ttype83]

On the drivers side rear there is a number for the carb. Can you tell us that number, it help. Does the carb and any electrical conections on it?
This problem could be a lean or rich condition caused by Vac leaks, carb out of tune or needing rebuild, or other problems.
Check all of your vac lines for cracking and/or leaking and replace.

20 Hg In of vac at idle is good, when you are driving it at 30mph what does the guage read?

 

[buickman1980]

A little more info -1980 Turbo Regal

I went ahead and replaced the plugs with new
Platinum plugs, new cap, rotor,wires, air
filter - It idles smoother, but high at
1500 rpms, it drops as low as 1K at times
now.
I went to buy a new carb today only to have
the local part stores that is a weird one
being a turbo - they claim the turbo was
a special carb - is this true ??? I did
find a vacuum leak between the main gasket
in between the two carb pieces. The parts
guys said the Quadrajets are better to just
replace if I can find one - Can I do an Edelbrock or Holley with it being a turbo ??
Here's the # off the carb - 17059243 , and
3198 CKD
Also, at idle I'm now at about 18 on the vac
gauge, at 30mph in 3rd gear I'm at 2K rpm and
about 12 on the vac gauge. It likes to boost
quick to +5 in high gears with lots of pedal - it starts cutting out at +7 until I
let off.
Any ideas - how do I do a wastegate check ?
Thanks,
Ryan

 

[b4black]

When you say "cuts out" does it just quit accelerating (hits a flat spot) or does it misfire and actually slow down?


Check you secondaries' air valves. They should open very easily and close on their own. It's common for them to get gunked up and not open easily.

Turbo Carbs are a little different. Thats a Turbo carb for a '79 TR. Should be OK. Numbers are here:
http://home.flash.net/~rjgeorge/carbs.htm


Are you running with the ESC (knock sensor- Turbo Control Center- Black Box)?

Do you have a PECR valve?
http://home.flash.net/~rjgeorge/images/vac80abfed.JPG

 

[buickman1980]

I do have the control box you speak of. I'll print your schematics
and check the other stuff when I get home ( man are those diagrams helpful ! -thanks )
I'm also going to take off the carb and clean it.
I also noticed the Fuel pump down under the car by the
gas tank - there is a fuel filter there I'm going to replace
as well.

Thanks for all the help. I'll be back with my results soon.

Ryan

 

[buickman1980]

New info

I finally decided to rebuild the carb, so I bought a kit and float. When I took the carb off, I noticed the gasket underneath had a gap on one of the secondary holes. This was where I found the vacuum leak while spraying carb cleaner when
running. The kit cam with one just like it, and one
about 3 times as thick. Which one should I use ?
I should have it back up and going tomorrow night.
The carb looked really clean otherwise.

There is a black turbo control box on the fender with a really
old relay right beside it. The connections look way old.

I still have yet to find the sensor, but I'll repost my finding
tomorrow.

Thanks for you help !

Ryan