New guy here needing some help from the pros

[1BUICKT]

I have an 87 Buick limited with the 3.8 turbo. The car runs and drives great as I use it as my daily driver. Im having two problems that Ive been trying to figure out that Im assuming are probably related. First the car is making to much boost. Ive changed out the vacuum lines from the wastegate actuator and turbo to the "Y" to the boost solenoid with new ones. Ive changed out the wastegate actuator itself as well as swapped the boost solenoid with a 6.5t.d solenoid w/caspers harness with no benificial results. Everything looks great as it should but the car still can produce up to 22lbs of boost.

The other problem is that at WOT my Buick flat falls on its face. At a slow speed or dead stop if I nail the accelerator to the floor the car will stall out badly... but if I just ease into the throttle the car will rocket as long as I keep an I on my boost gauge not allowing it to go past 17lbs or so (no knock).

The mods on my Buick are light for now consisting of a Scanmaster, Autometer Pro-Comp Boost & Fuel pressure gauges, RJC powerplate, K&N filter in the factory housing, Hotwire harness, Accufab adjustable fuel pressure reg., TT 91 chip, & an ATR dual exhaust. Ive recently done a tune up with new plugs and wires as well with no help to my problem.

My Scanmaster readings at idle are as follows...

02- 773
AF- 06
L8- 44
BAT- 13.4
INT- 128
BL- 124
MPH- 0
CLT- 207 (99 degrees outside and A/C running at max)
ATS- 118
r- 775
TPS- 48
IAC- 46
cc- 29
NAL- 00

Any help would be greatly appreciated! Happy 4th of July everyone!

 

[Mr.Spool]

have you adjusted the wategate rod?your saying the car pulls to 17psi o knock but you cant get to 22 without issues?is there race gas or alky injection on the car?please dont tell me you are boosting to 22 psi on 91 octane.

 

[1BUICKT]

have you adjusted the wategate rod?your saying the car pulls to 17psi o knock but you cant get to 22 without issues?is there race gas or alky injection on the car?please dont tell me you are boosting to 22 psi on 91 octane.

Thanks for the reply. My buick has a factory type wastegate actuator so its non-adjustable. I can take it up to about 17 with no knock but if I stay on the throttle it will continue to rise to crazy numbers.

 

[Mr.Spool]

do you have race gas or alky injection on the car?if you dont you need to stop going over 15psi or you will have bigger problems.

 

[1BUICKT]

do you have race gas or alky injection on the car?if you dont you need to stop going over 15psi or you will have bigger problems.

Thats why I posted this topic asking for help.. Im just running straight 91 octane.

 

[Mr.Spool]

22 psi on 91 octane is a no-no my friend you will hurt the motor.

 

[1BUICKT]

22 psi on 91 octane is a no-no my friend you will hurt the motor.

Yes, I am fully aware... thats why Im asking to see if others can chime in on why my car is doing this and how to fix the problem. Im obviously not wanting to run 22lbs of boost with just the light mods done to my car. I want it to be at a safer 15-17psi max... oh, and also be able to go WOT from a full stop or light roll.

 

[mikestertwo]

What are you using to measure boost? When you disconnect the wastegate actuator from the turbo does the waste gate move freely? When you replaced the wastegate actuator did you replace it with another stock one? Remove the "Y" hose and run a hose straight from the compressor side of the turbo to the wastegate actuator and see how much boost it makes.

 

[1BUICKT]

What are you using to measure boost? When you disconnect the wastegate actuator from the turbo does the waste gate move freely? When you replaced the wastegate actuator did you replace it with another stock one? Remove the "Y" hose and run a hose straight from the compressor side of the turbo to the wastegate actuator and see how much boost it makes.

Im using my Autometer Pro-Comp boost gauge to measure boost and yes, I replaced the actuator with another stock one. The wastegate did move freely when it was disconnected.

 

[mikestertwo]

Run a hose straight from the compessor to the wastegate actuator and see how much boost you make. Also verify with another gauge. When did this problem start? Make any changes somewhere?

 

[1BUICKT]

Run a hose straight from the compessor to the wastegate actuator and see how much boost you make. Also verify with another gauge. When did this problem start? Make any changes somewhere?

I will definitely run the straight hose like your saying and check boost. Ive owned my Buick for roughly 6 months and Im thinking that the boost issue has been there since then, I know the problem Im having with WOT has. I didnt figure it until I hooked up the gauge and saw the results. It moves the same as the factory boost gauge but goes further when the factory gauge maxes out so Im really not thinking there's a problem with it. I also cureently dont have another gauge to replace it with to check. Btw, thanks alot for your input and help on this.

 

[Nigel]

Hook the compressor vacuum hose directly to the waste gate, see what happens with your boost. If everything else is correct, you boost will be around 8 lbs.

 

[mikestertwo]

What turbo and what kind of exhaust is on the car? 3" DP ? What kind of mods on the car?

 

[1BUICKT]

What turbo and what kind of exhaust is on the car? 3" DP ? What kind of mods on the car?

Stock turbo, stock dp with cat... Scanmaster, Autometer Pro-Comp Boost & Fuel pressure gauges, RJC powerplate, K&N filter in the factory housing, Hotwire harness, Accufab adjustable fuel pressure reg., TT 91 chip, & an ATR dual exhaust. Ive recently done a tune up with new plugs and wires as well with no help to my problem.

With it being 4th of July and having family here at my place I wasnt able to run the straight hose on the Buick, but I will be sure to do it first thing in the morning.

 

[John Larkin]

IAC and TPS is a little high. IAC should be around 15 hot idle in park, TPS should be 0.42 throttle closed and 4.60-ish WOT not to exceed 4.80. You have a really nice idle which is a good thing. Just a couple of adjustments, sometimes small things make a difference. Do you have an upgraded fuel pump? If not I have two lightly used I just removed from my car for half price of new if interested. Here are a couple links for IAC and TPS:

http://www.gnttype.org/techarea/maintenance/TPS.html
http://www.gnttype.org/techarea/faq/IACresetscan.html

 

[HelloBozos]

I agree with the above, set the TPS,check MAF sensor for the throttle issues.
If you put a stock chip in (or do you have one?) the boost still high?
Most people have problem getting over 17lbs boost on non-cut Actuator until cutting it an adding a release valve inline with solinoid.
Your a rare case of Not wanting alot of boost...heh

Enjoy!

 

[1BUICKT]

I went out today and drove my Buick to get it up to operating temperature the parked and made the tps and iac adjustaments... drove it around some more, then double checked my results..

02- 710
AF- 04
L8- 33
BAT- 14.1
INT- 128
BL- 127
MPH- 00
CLT- 182
ATS- 94
r- 750-775
TPS- .44
IAC- 15
cc- 213
NAL- 00

With the adjustments made it feels like the car has picked up a little better acceleration but still cuts out at WOT.
Im waiting for it to cool down now to run the straight hose and check the boost.

 

[1BUICKT]

I agree with the above, set the TPS,check MAF sensor for the throttle issues.
If you put a stock chip in (or do you have one?) the boost still high?
Most people have problem getting over 17lbs boost on non-cut Actuator until cutting it an adding a release valve inline with solinoid.
Your a rare case of Not wanting alot of boost...heh

Enjoy!

I unfortuantely do not have a stock chip, just the TT chip thats currently in the car and the pitbull chip that was in it when I purchased my Buick. More boost will be wanted Im sure a further down the road, right now Im just really wanting it running right with the combonation that Ive got. Im having alot of fun with this car as is!

 

[TurboTnZ06]

Don't run the stock chip- it has way too much timing for the E10 pump gas we run these days.

 

[Jerryl]

02- 710
AF- 04
L8- 33
INT- 128
BL- 127
r- 750-775
IAC- 15

AF seems low indicating the MAF may be on it's way out.
What are the O2's at WOT?