1979-1993 & 94 Conv [Subscribe to Daily Digest] |
If you get a dramatic power cut, face in the windshield, you are not hitting knock sensor intrusion, but rather fuel pump shut down. On a 90 you cannot avoid this like on earlier models, which had an overboost switch that could be jumpered. Your fuel pump shut off is signalled from the AMM reaching an air flow/mass limit. The only way to beat this is by putting in 30 lb injectors and adding a resistor to the orange AMM wire, give or take 100ohms.
The knock sensor intrusion is more of a pulsing where the boost is cut momentarily and then it has to spool up again. Annoying, but not dramatic. Intrusion varies by car and depends on the temp that the engine runs at, the amount of carbon in the combustion chamber, condition of injectors, fpr, plugs, the whole deal. If you get intrusion at WOT boost, you can increase the spark retard under boost to limit boost. Remove the distributor cap, unbolt the distributor clamp and lift out the distributor. Unscrew the distirbutor control module on the side and unhook the arm from the peg. Once you get use to this, you can do it with the distributor in the car, but first time is easier with the dist pulled.
Now you will notice a round peg on the arm that limits the amount of retard under boost. YOu can bend it but IMO filing works better. Very gently file off a little of the round button to increase the retard. If you file off 1/8 of the diameter, you have over done it and you will get too much retard and loose lots of mid range grunt.BTDT Then you get to turn the button around and start over.
Anyway, after you have filed off a little, put the module back on and install the distributor, set the timing to 16btdc at idle and go for a test drive. If ther is still knock intrusion file off a little more. By trial and error you can stop the knock. By the time you have stopped the knock, you probably will start losing the mid-range ummph. If so, advance the base timing from 16btdc to as much as 20 btdc to improve performance. If you don't do this you will get huge boost way to the end of red, but not have much power.
The right way to do this is really to start with a pressure pump and a dialable timing light before you begin the filing. This way you can determine spark retard at various boost levels. Then you do this each time you file some off, you re-measure advance at various pressure levels. You will notice that max retard happens with very little boost, and this is why you have to advance the basic timing, so you don't end up with a very retarded engine.
posted by 208.208.152...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
