84 GN overboosting.

[KenSeggie]

I have a 84 GN with a new turbo that runs good most of the time.Problem is it over boosts under full throttle and pings bad.I've replaced the 2 vacuum lines to the waistegate but still the same problem.Beofre I replace all the vacuum lines can some tell me how to bypass the waistegate solinoid to make sure that is not the problem.The waistegate looks fairly new and seems to be working.Any other ideas would be appreciated.
Thanks.

 

[esinger]

One easy test I'd do is unhook the wastegate (as in take the control arm off) and make sure the puck isn't stuck. With the wastegate unhooked you should make very little boost.

 

[Boost231]

One easy test I'd do is unhook the wastegate (as in take the control arm off) and make sure the puck isn't stuck. With the wastegate unhooked you should make very little boost.

+1 good test.

 

[KenSeggie]

One easy test I'd do is unhook the wastegate (as in take the control arm off) and make sure the puck isn't stuck. With the wastegate unhooked you should make very little boost.

Tried that.No boost.
Thanks

 

[SLOW_85]

Just a thought does it have the restricted Y in the vacuum line?

 

[Waco84GN]

RJC Booost control valve

I got a RJC boost valve on my 84 after having similar issues. Pegging a 30 lb boost gauge and blowing my intercooler hoses off. I ran a vac. hose from the compressor scroll elbow to the rjc valve inlet. From the exit of the valve to the inside port on the wastegate. One closest to the turbo so it can force the wastegate open after the valve lets the boost pressure through. I can back this valve all the way off and hammer the car and it will have a slight blip over 12lb and then come back down and be rock steady at 12lb all day. I have since taken the lock nut off the valve in pursuit of higher boost numbers and have gotten 23 -24 lb at the track with no spikes.

The valve is around $40, but is probably the best $40 I have spent on the car as far as making the car reliable and safe.

Jerry Berger Jr.

 

[KenSeggie]

I checked that today.It's all clear.Even found a crimped vacuum hose behind the Y.Fixed that but still the same problem.I'm thinking the waistegate solinoid is bad.Does anyone know if it'd different from an 87?
Thanks.

Just a thought does it have the restricted Y in the vacuum line?

 

[KenSeggie]

This sounds good.I may try it.
Thanks.

I got a RJC boost valve on my 84 after having similar issues. Pegging a 30 lb boost gauge and blowing my intercooler hoses off. I ran a vac. hose from the compressor scroll elbow to the rjc valve inlet. From the exit of the valve to the inside port on the wastegate. One closest to the turbo so it can force the wastegate open after the valve lets the boost pressure through. I can back this valve all the way off and hammer the car and it will have a slight blip over 12lb and then come back down and be rock steady at 12lb all day. I have since taken the lock nut off the valve in pursuit of higher boost numbers and have gotten 23 -24 lb at the track with no spikes.

The valve is around $40, but is probably the best $40 I have spent on the car as far as making the car reliable and safe.

Jerry Berger Jr.

 

[TurboRegal84]

Do you have a knock gauge or scantool? If you can HEAR the knock it is VERY BAD!

Does your car have an adjustable wastegate (With Threads) on the arm? If it does you need to adjust the wastegate rod so that more threads are showing. This will lower the amount of boost your car is producing thus hopefully eliminating the knock.

 

[19GN85]

I got a question about the waste gate too. I try to wiggle the wastegate arm to see if the puck moves but doesn't seem to want to budge. Is the solenoid holding it that firm? If I disconnect it from the turbo should the puck move freely?

 

[Waco84GN]

puck movement

the wastegate arm is holding the puck pretty firmly. With the arm off the puck the puck should move very freely with little resistance. I would leave the wastegate rod off until you get a known good solenoid or some other method of boost management. The pinging sound you hear is the noise you hear right before you blow a head gasket. I would advise to not boost the car hard unless you have some good gas in the car.

Jerry Berger

 

[KenSeggie]

Thanks.Stock waistegate.I tried spacing the waistegate to give the rod more travel.You can't make the stock rod much longer before there is no tension on the puck.Yes I know ping is bad.Been working on 87s for 20 yearsThis problem is either the waistegate or solinoid.Wish i had some spares.I might try and adapt an 87 gate to see what happens.RJC valve would be good as it would eliminate solinoid.
Thanks.


QUOTE=TurboRegal84;1950143]Do you have a knock gauge or scantool? If you can HEAR the knock it is VERY BAD!

Does your car have an adjustable wastegate (With Threads) on the arm? If it does you need to adjust the wastegate rod so that more threads are showing. This will lower the amount of boost your car is producing thus hopefully eliminating the knock.[/QUOTE]

 

[BadAssGN]

Been working on these cars for 20 years and you don't know how to solve a simple boost problem?

The Soleniod is an air purging device.

Plug the hose to the solenoid and this will provide full pressure to the actuator.

Have you applied air pressure to the actuator to see if the diaphram is intact??

Thanks.Stock waistegate.I tried spacing the waistegate to give the rod more travel.You can't make the stock rod much longer before there is no tension on the puck.Yes I know ping is bad.Been working on 87s for 20 yearsThis problem is either the waistegate or solinoid.Wish i had some spares.I might try and adapt an 87 gate to see what happens.RJC valve would be good as it would eliminate solinoid.
Thanks.


QUOTE=TurboRegal84;1950143]Do you have a knock gauge or scantool? If you can HEAR the knock it is VERY BAD!

Does your car have an adjustable wastegate (With Threads) on the arm? If it does you need to adjust the wastegate rod so that more threads are showing. This will lower the amount of boost your car is producing thus hopefully eliminating the knock.

[/QUOTE]

 

[Jerryl]

I have a 84 GN with a new turbo that runs good most of the time.Problem is it over boosts under full throttle and pings bad.I've replaced the 2 vacuum lines to the waistegate but still the same problem.Beofre I replace all the vacuum lines can some tell me how to bypass the waistegate solinoid to make sure that is not the problem.The waistegate looks fairly new and seems to be working.Any other ideas would be appreciated.
Thanks.

Thanks.Stock waistegate.I tried spacing the waistegate to give the rod more travel.You can't make the stock rod much longer before there is no tension on the puck.Yes I know ping is bad.Been working on 87s for 20 yearsThis problem is either the waistegate or solinoid.Wish i had some spares.I might try and adapt an 87 gate to see what happens.RJC valve would be good as it would eliminate solinoid.
Thanks.

Hey ken.
To get a better idea of "overboost" and "ping" you are experiencing, can you an swer this?
(1) How are you measuring boost, (2) how much boost, (3) and how much KR?
FWIW, It is not your solenoid that is causing the problem.

 

[KenSeggie]

Been working on these cars for 20 years and you don't know how to solve a simple boost problem?

The Soleniod is an air purging device.

Plug the hose to the solenoid and this will provide full pressure to the actuator.

Have you applied air pressure to the actuator to see if the diaphram is
intact??

[/QUOTE]

That's right.I just havn't had a lot of experience with hot air cars.Mostly 86-87s.There is more then one hose going to the solinoid.And yes the actuator is working.

 

[KenSeggie]

Hey ken.
To get a better idea of "overboost" and "ping" you are experiencing, can you an swer this?
(1) How are you measuring boost, (2) how much boost, (3) and how much KR?
FWIW, It is not your solenoid that is causing the problem.

VDO boost gauge pegs 17#s before I get out of it.I didn't bother measuring knock as I can tell by the sound it's bad.
Thanks.

 

[TType84]

ken,

ever get this problem fixed?

and lol @ people trying to act like you dont know what you're doing when it comes to buicks...

 

[T-Type85David]

as for the wastegate solenoid, i know they dont make them anymore (i think) but i know of a diesal part but dont know the #it was on a buick HA site somewhere. is this a good replacement part for our HA?? Or should one go with a different method of boost control/solenoid device??

 

[TType84]

as for the wastegate solenoid, i know they dont make them anymore (i think) but i know of a diesal part but dont know the #it was on a buick HA site somewhere. is this a good replacement part for our HA?? Or should one go with a different method of boost control/solenoid device??

you can use a charcoal canister solenoid off certain year model S-series trucks. other canister solenoids will fit but i believe the one on the specific apps have the same setup with the two nipples parallel to eachother.

do yourself a favor and get rid of that dumb ass solenoid. as silly as it sounds, a manual boost controller made out of a ball bearing, some brass pipe fittings and a spring is infinitely more reliable than some 25 year old electronics.