90 CAS in a 95 misfires often?

[honduraneclipse]

I am sick and tired of shutting off the engine and then turning it back on so it can stop misfiring. To make a long story short my 95 gst 6 bolt misfires after, easing of the gas and also after climbing over exactly 3500 rpm. I am pretty sure its not my coil pack/wires/plugs. The CEL is of course always on, I guess its true many 6 bolt swaps dont turn out perfect without DSM LINK. I am sure i could deal with this problem without it but, I need some advice from you guys which might have had the same or similar problems.
thanks in advance dayan

 

[BigBADGSX]

IF CHECK ENGINE LIGHTS OCCUR! TRY THIS:

(Blake Heisler's Fix for misfire Check Engine Lights (CELs) when putting a 1G Cam Angle Sensor (CAS) on a 2G)

Many people using the 1G CAS on a 2G head have been running into problems with misfire engine codes while at cruise. Many different things have been blamed for this and many different fixes have been attempted.

This fix will keep the ECU from looking for misfires at all. This is the criterion that must be met before the ECU will start to look for misfires:

1. 300+ seconds of steady state RPM less than 80% throttle position

2. Engine coolant temperature -10C or higher

3. Intake air temperature -10C or higher

4. Barometric pressure greater than 76 kPa

Now if we can get one of these values outside of the criteria the ECU won’t check for misfires. The value that would be the easiest to change would be the barometric pressure sensor. We’re going to add resistance to this value so that the ECU will see less barometric pressure than what there really is. This will also lean the car out so you should see a performance increase as well. Depending on the car and altitude you might need to add more fuel with an AFC.

So let’s get started, Parts needed:

A 10K potentiometer (although a 5K would probably do just fine). These are available at any electronics store, if you go to Radio Shack ask for a volume control knob because they don’t know what a potentiometer is

Wire strippers

Soldering iron

Step 1: Remove the access panel on the driver’s side of the center console. You should now see four plugs with a ton of wires going to them.

Step 2: Pull out the top plug, it’ll be the one that’s the hardest to reach. Locate wire #85. It’s orange with a white stripe.

Step 3: Cut the orange wire in half. Solder one end of the wire to the center peg of your potentiometer. Solder the other end to either the left or right leg, it doesn’t matter which. Turn your potentiometer all the way counter-clockwise.

Step 4: Plug the harness back in and start up the car. It should sound like it did before you did any modifications. If the idle is choppy or the car won’t run you turned your potentiometer the wrong way.

Step 5: Add resistance to the barometric pressure sensor by slowly turning the knob on the potentiometer. Drive the car around; if you get a CEL then add some more resistance. Keep doing this until you no longer get the CELs.

That’s it, special thanks to Marco for pioneering this mod and to all the guys on the DSM1Gina2G Yahoo group for all the discussion, ideas, etc.

-Blake Heisler

hope this helps...

if you have any more questions go to www.magnusmotorsports.com this is where the best tech article for the 6bolt swap is.

good luck

 

[honduraneclipse]

thanks i might try that ASAP i would get back to you with the results

 

[ADrewzki]

Mine did the same thing around 3k rpm. I drove around with the pocketlogger clearing the error as I went. The 10k potentiometer thing didn't do much. SLIGHTLY lessened the occurence of it but didn't eliminate it. Over time though, it flags the misfire a lot less. Just be careful not to lean it out too much.