First off, no I do not have a scanmaster yet. I bought the car not running about 6 months ago, and had to build the motor. I just got it back up and running yesterday. The chip says on the bottom 86-87 strt lthl. So part throttle is really nice, drives around great. But when it starts building boost, it does not start pulling until it gets past 6 psi. No black smoke or sputtering, just not doing like it should until the boost gets over that "hump".
Engine labors from start of boost up to 6psi
- Thread starter BMR
- Start date
The cel was flashing rapidly yesterday and after reading on that problem, I went out this morning and popped the chip out and re inserted it. I had also been sitting all night with the battery disconnected, but after that no cel at all. Come on with switch, then off with engine running. Seems to act better now. The roads are wet, so it just spins, but throttle response is better.
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
Park the car...and order a chip from Eric...before you hurt that engine. God only knows what that chip is burned for.
- Joined
- Nov 30, 2009
X2 .... Those early chips had aggressive timing for the gas of the day , Smart move on the 110 gas , could have hurt it on pump gas .
- Joined
- May 26, 2001
There are about 20 "causes" I can think of to start, and the chip is not at the top of the list.
If I were to approach this issue, the first area I would check is the mechanical state of the engine and pull the spark plugs. If they look ok, a compression test would be in order since the plugs are removed.
I could also be something in the add-on parts if any, and that combination could be affecting drivability?
You have no mention of the turbo and converter as the wrong combination there will do exactly what you state.
No dis-respect intended, but if your experience with turbo Buicks is limited to a basket case you put together the past 6 months, try to find someone qualified near you to obtain help to get this right.
#1 issue (tie) ive been finding in these cars over the last 5 years is wrong converter and or exhaust leakage pre turbo. This doesnt mean you can hear it because it can be leaking at the puck. Many new pipes with more than one issue and many old ones that had the issue from the beginning. Gaskets should not be used on the swing valve type pipes. The geometry is altered and the puck may not sit flat. Ive seen many that wouldnt sit flat even when no gasket is used. It is up to the installer to determine if the pipe was made correctly and by whatever means fix any issues before it is installed on the car. New does not mean good. To me it means i better look over this aftermarket part and find out whats wrong with it before it goes on this car before i create a big headache for myself when the cars performance is off and i have to back track. Anytime anything is changed this exact thing goes through my mind. Just about everything needs a little tweaking.
I am not concerned with the condition of the engine. I just assembled it last week. Fresh bore, rings bearings, balance, bearing clearance between .001 and .0015.
Stock turbo, stock converter. What else
Is on the check list?
I knew the subject of my experience with these cars would come up. I have minimal experience with these cars. However, this is just a driver. I built an tuned the junk malibu in my sig...if I want to go 9s at 150ish, I will get in it.
This GN is just a family cruiser. The
only reason the cam is changed is because it had a 218 in it when i got it and it was unacceptable.
Stock turbo, stock converter. What else
Is on the check list?
I knew the subject of my experience with these cars would come up. I have minimal experience with these cars. However, this is just a driver. I built an tuned the junk malibu in my sig...if I want to go 9s at 150ish, I will get in it.
This GN is just a family cruiser. The
only reason the cam is changed is because it had a 218 in it when i got it and it was unacceptable.
Stock manifolds with a thin coat of copper seal only. Driver side already welded back up. Stock turbo, actuator, and down pipe.
It Is spooling quick and easy. It makes boost as soon as you ease down on the pedal just like I believe it should. It just seems down on power in the low boost area.
It Is spooling quick and easy. It makes boost as soon as you ease down on the pedal just like I believe it should. It just seems down on power in the low boost area.
Evil and Bison are correct about it having an exhaust leak. I just fired it up and felt around the turbo and it is leaking between turbo and manifold. What plugs are you guys using? Is has some used R5674-8 NGKs from when i had iron heads on my Malibu.
It also does not want to idle correctly. When the cel was flashing it idled perfectly.
It also does not want to idle correctly. When the cel was flashing it idled perfectly.
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
Stock plugs are 44's.
RmvBfrFlght
Well-Known Member
- Joined
- Sep 28, 2007
With the stock iron heads can use an Autolite #23 for an extended tip plug. For a non-extended tip use the Autolite # 144 plug. These are both a resistor and copper core type plug.
As for the better idle with the flashing CEL, the ECM was in limp mode during that time (flashing CEL). This is where the ECM uses backup fueling and no spark advance beyond the initial of 10* BTDC. If the injectors flow more then stock then the fueling was rich.
Being rich helps with idle. The other part is that when the ECM is running from the chip (non-flashing CEL), the ECM is most likely going into closed loop mode. In this case the idle fueling will be leaner.
RemoveBeforeFlight
As for the better idle with the flashing CEL, the ECM was in limp mode during that time (flashing CEL). This is where the ECM uses backup fueling and no spark advance beyond the initial of 10* BTDC. If the injectors flow more then stock then the fueling was rich.
Being rich helps with idle. The other part is that when the ECM is running from the chip (non-flashing CEL), the ECM is most likely going into closed loop mode. In this case the idle fueling will be leaner.
RemoveBeforeFlight
