Overboost?

A

Alliemax

New member
Just picked up a Sy tonight which was just serviced and the wastegate solenoid replaced after codes checked. Truck has not been driven much till the 100 mile drive home. Twice under full throttle the engine cut out and check engine light lit up. After I turned it off and drove again under full throttle it didn't repeat itself. I did gas up on the way home. Truck has 20,000 miles on it.

Any ideas? What should I do?

Thanks
 
jwaller

jwaller

Evil Genius/SyTy Guru
this is classic overboost. I am going to assume that with 20k miles it's all stock.and the WG is sticky BC it doesnt have many miles on it after 10 yrs....so you need to get a scantool so you can confirm that your overboosting.. then you will want to make some WG adjustments so that this will not occur..I would prob start with 1 turn out on the WG rod.
 
Daron

Daron

Active member
Dig discovered the ol' sticky wastegate syndrome sometime back and said the cure was some GM "High Temp lube" that can be purchased at the dealer. Gotta get the turbo nice and hot, then check wastegate movement. I'd go thru everything, from adjusting the wastegate rod to stock length to replacing the rubber elbos on the vacuum lines. You just never know what the previous owner/dealer did to the truck.
 
jwaller

jwaller

Evil Genius/SyTy Guru
you can easily adjust the rod by removing the RF inner fender...lots of rusty bolts...then you wil see the rod attached to the rusty side of the turbo....losen the jam nut on the backside of the rodend. then remove the pin holding rod to WG arm. rmove arm .then turn 1 turn out. reinstall in rev order and whilke your in there take some pliers and try to move the arm in and out..it should be easy to move but not totally free...you should feel some spring pressure from the WG acuator.

_________________
TE-60, ATR headers, Vortecs, TCS converter, 50# chip, NOS Profogger

<font size=-1>[ This Message was edited by: jwaller on 2001-12-30 21:09 ]</font>
 
Daron

Daron

Active member
On 2001-12-30 21:22, jwaller wrote:
you win...for now.. :smile: :grin: I just don't have the power.
Click to expand...

My staying power stems from a visit by my mother in law. The computer is one escape, the garage is the other... :wink: Like overboost, she sets diagnostic trouble codes in my mind. Here I can ignore the pain.

<font size=-1>[ This Message was edited by: Daron on 2001-12-30 21:33 ]</font>
 
jwaller

jwaller

Evil Genius/SyTy Guru
thats just funny.....:smile:..I'm stuck at the office..I'm in the process of changing engines on the plane..so I'm taking a break for a little while...went from 4am-10pm yesterday and 7am-? today.
 
A

Alliemax

New member
The truck has not cut-out or light come on(apparent overboost) since the trip home. I took it out since and no problems. Is overboost something that should happen all the time. I guess what I am asking is since the truck (stock) has not been driven regularly is this something that could have occurred, but then resolved itself during the drive. The prior owner just had it in within the last month to replace the wastegate solenoid to correct this problem and the other items were considered.

What risk do I run if the engine light and the cutout is not occuring anymore and it is driven? Will the motor blow with overboost?

Pardon my questions and thanks for your patience.




Thanks for the help,

Mark
 
G

Guest

Guest
The main thing would be to get an aftermarket boost gauge (mechanical) so that you can keep an eye on it. The stocker is just no good. If you start to go over 15lbs of boost get off the gas. You can eventually blow the motor. Also get something to monitor knock and, like i did with my 20,000 mile sy that had been sitting since 96, run som top engine cleaner through and tune it up. Your vac lines are probably crap too so get with Ian and get some new ones.

_________________
IMAG0007.JPG


Thats a beautiful thang.

91' Sy 760 (Daily Driver)

<font size=-1>[ This Message was edited by: ncsyclone0760 on 2001-12-30 22:36 ]</font>
 
A

Alliemax

New member
This Sy's number is 567, three behind yours. Where is the best place to get the boost gauge and how do I contact Ian for the vac lines.

Thanks,

Mark
 
G

Guest

Guest
I got my boost gauge from http://www.summitracing.com . They have quite a few colors to choose from. Make sure you get the mechanical and get something that goes to 30lbs of boost. Ron Gregory sells a fitting that will allow you to tap in to the brake boost line. Go over to the links on the side and go to Rons fuel pumps. Call him and he'll make sure you get what you need. Lo-tec engineering makes a 2-3 gauge a piller pod to hold the gauges nicely and someone make a 1 gauge pod (a little help here). You may wany to get an electrical fuel pressure gauge too to go in the pod with the boost gauge. all and all you'll have around $200 for 2 gauges the 2 gauge pod and all the adapters.
 
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