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View Full Version : Too much boost!



svobrown
10-23-2002, 09:09 PM
Got the svo running good but now I can not control the boost at all. Spikes up to 20+ psi. Does this mean that the waste gate is shut and is not opening? Is there a quick fix to this? Can not drive it like this.
Blew off the ic hose when I first found out. Took the valve out and the same thing happens.

84 svo has a 88 tc motor in it, LA3 with a t3 rebuilt about 2 years ago with 5000 miles on the t3 now. Hoses in poor shape on the gills control valve but no leaks. Front monut super coupe ic on it with 2.5 hose all the way thru. 3" down and 3" duel mac.
255 fuel pump, new.

Has 6 psi boost when I rev motor with out being in gear. Timeing is 10 deg neg with spout out. sounds great when it gets round 3000 rpms then gets datenations cause of all of the air going in the poor thing.
Do not drive this one very offen. Bout once a month I run it and all has been well.
Thanks for any help given.

svobud
10-23-2002, 10:20 PM
you might check your wastgate....more importantly, the rod actuator arm. If it's not the actuator - pull the wastegate and inspect, it's probably bad.

but have you tried turning your boost valve adjustment to the right?

140cilx
10-24-2002, 08:51 AM
When I was getting the turbo ready for my '88 I checked the wastegate by turning my air compressor down to 10 psi output, stuck the nozzle on the wastegate vacuum hose. It would hold the wastegate open no problem, no hissing no leaks. My buddy on the other hand could not make his open, it blew out through the torn diaphram, and the wastegate would not open, he was getting full boost just like you described.

-just an idea for checking.

svobrown
10-24-2002, 09:49 PM
Its like it is welded shut. Can not move it by hand.
I may just drag the thing around this weekend.
Hope to see everyone at the show.
Thanks for the help.

gbeaird
10-25-2002, 12:58 PM
Check the waste gate. Sounds like it is stuck/rusted shut. Reving the engine in neutral is no way to test this. The engine is not under load, and you will NOT get any usable information out of it other than the fact that your engine will rev. You have to put it under a load to find out what the turbo will do.

Gene Beaird
86 2R SVO
Pearland, Texas

svobrown
10-27-2002, 06:49 PM
Pulled the svo in my shop to start rebuild of motor and turbo. Had oil running everywhere so I know the seals are gone in front and back. Have good place to get the turbo from and have all winter to play in the shop.
Got some good info on porting a head and saw a better way to run my wires in the motor bay.
Watch out Ty I may even get it running for the next svoca meet.
Want to try out the brakes from the car show. SWEET!
Thanks to all.
Hey Roger thanks for the seats! Much better than what I had in it.