Overboosts and shuts off

12secondSY

Syty Killer :(
The guy I sold the syclone too is having problems with it. Ran fine at the track before I sold it and from there only drove it a couple times and it ran great. The only thing that changed was that I had already sold the stock airbox setup and took it off then never drove it after that until he came to pick it up. He said that the first night it was overboosting to over 20 psi and shutting down. He also said on the launch he would hold over 10psi and it would come out hard and then shut down by the end of 1st gear and then go again. Once in a while it will run ok and sometimes not shut down till later on like maybe end of second or 3rd gear. He got the boost to stay down to 10psi and said it still shuts down. This truck only has free mods and everthing seems to be hooked up right. He never put anything in place of the airbox(its open turbo), could that cause it? He also said he put on the scan tool and everything checked out ok. Engine light would pop on for about 10 seconds then shut off and not save a code. Thanks for any help, he thinks I sold him a junk truck.
 

GM TURBO

Sell Out
Re: Overboosts and shuts off

Overboost will shut the truck down if it sees over 14.7# of boost for longer than 2 secs (approx).

I'd adjust the wastegate a bit or go external - especially if he is running without a cat.
 

12secondSY

Syty Killer :(
Re: Overboosts and shuts off

It has a cat and when it did occasionally overboost for me(only under high load like if I stomped on it from 50mph roll) it never shut down it just made all kinds of noise. It acts like for him what it would do to me when I was getting low on gas. But hes running a full tank. Maybe he messed with it and isnt telling me. I never had any problems with it like he is complaining about.
 

jwaller

Evil Genius/SyTy Guru
Re: Overboosts and shuts off

are you sure it's full of gas? and prop hitting the overboost as well.
 

critical

meltdown
Re: Overboosts and shuts off

Make sure the w-g solenoid is hooked up the correct way.
My sy did the same thing when i first bought it. The vent port was capped off.
 

12secondSY

Syty Killer :(
Re: Overboosts and shuts off

Its full of gas, it will do it on a completely full tank. Got it to stop overboosting and it still does it. Has a stock fuel pump with 70K. Could it be going bad maybe? I told him to try it since he has plans to mod it over the winter and will need a bigger one anyways.
 
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