All of these engines use GM Direct Ignition System (DIS) which is a “waste spark” ignition with a coil pack for each pair of mated cylinders. These MSnS-E Compatible Engines have several things in common.
MEGATUNE SETTINGS FOR MULTIPLE COIL CODE
*Note* the term “VIN x” refers to the 8th digit of the Vehicle Identification Number which indicates the ENGINE CODE or VIN CODE for the applicable engine (High Output) 1987-92 N Cars 1990-92 L Cars 1990-91 W Carsġ988- 1992 2.3 VIN D (LD2) Quad 4 DOHC 1987-92 N Cars 1990-92 L Cars 1990-91 W Carsġ992 - Only VIN 3 (L40) Quad 4 SOHC 1992 N cars (Grand Am, Achieva, Skylark)ġ990-1991 2.2 VIN G used in Beretta Cavalier Corsicaġ991- 1994 1.9 VIN 9 Saturn SOHC (Single Over Head Cam) w/TBIġ995- 1995 1.9 VIN 8 Saturn SOHC (Single Over Head Cam)ġ991- 1995 1.9 VIN 7 Saturn DOHC (Dual Over Head Cam)ġ992-1993 2.2 VIN 4 used in Cavalier, Corsica, Berretta, Century, Cutlass Cieraġ994-1995 2.2 VIN 4 used in Chevy S10 and GMC Sonoma These are to be referred to as “MSnS-E Compatible Engines.”ġ987-1989 2.0 VIN 1 used in Beretta, Cavalier, Corsica Skyhawk, Tempest, Firenzaġ987- 1992 2.5 VIN R/U) used in Fiero, Grand Am, 6000, Cutlass Ciera, Cutlass Calais, Celebrity, Lumina, Century, Skylarkġ988- 1992 2.3 VIN A (LG0) Quad 4 DOHC H.O. The following North American 4 cyl engines that use GM DIS are current directly compatible with Megasquirt rev 2.2 using MSnS-E. * unless otherwise noted, all references to Megasquirt are referring to PCB Rev 2.2 Megasquirt 4 cylinder DIS Compatibility/ Conversion and Parts Summary This about sums up the procedure for replacing our existing DIS system with the older preobd2 DIS system, WITH part numbers (not guaranteed to be accurate). I can post 2.2L timing curves (both mine and stock) but with the combustion chambers in the 2200 being "new and improved" (how can they be both?) I don't know how close the older spark values will be. I have said before that it would be extremely cool to log OBDII data while driving around to compile a timing map for the 2200. Lots of highway time is extremely helpful in this regard. If you can cruise with the least throttle opening, you should be getting the best mileage.
![megatune settings for multiple coil megatune settings for multiple coil](http://megasquirt.free.fr/sources/MS/manual/v22manual/mt_ani.gif)
So far the best way to lock in cruise timing seems to be picking an AFR then varying timing by a few degrees + or - to see what affect it has on TPS. Retarding timing tends to cause the exhaust gas to indicate a lean condition. Wide band readings are affected by timing. The engine does not warm up quickly enough to cause a serious lag in reported temperature.
![megatune settings for multiple coil megatune settings for multiple coil](http://www.useasydocs.com/details/injectors.gif)
Placing the sensor in the block but outside the path of coolant usually works well. When an engine is first warming up the t-stat can go through several rapid open / close cycles. The t-stat blocks coolant flow until temp is reached, then it quickly opens. Placing the CTS above the thermostat is also an invitation for problems, as the sensor will not indicate correct engine temp during warmup. Sharing the sensor is definitely an invitation for problems.
MEGATUNE SETTINGS FOR MULTIPLE COIL MANUALS
My wiring diagrams and service manuals don't indicate any reason to use an OBDI ignition module, though practical experience may say otherwise.Ĭoolant temp circuit inside the ecm/ pcm does indeed switch pullup resistors.
![megatune settings for multiple coil megatune settings for multiple coil](http://megasquirt.free.fr/sources/MS/manual/v22manual/mt_cs.gif)
Connect the system using the same wiring, use the correct reference angle, and you'll have a reliable system. The GM OBDI and many OBDII DIS systems are exactly the same as the HEI system from the ecm/ pcm's point of view. Waste spark systems are used on motorcycles and snowmobiles with magnetos, automobiles with points, Ford, Dodge, and GM systems as well as import cars. Waste spark does not describe the triggering system. Waste spark connects both ends of the secondary side of the coil to a spark plug, and each plug is in one of two cylinders seeing TDC at the same time. Waste spark describes the arrangement of spark plugs and coils. I'd love to get some reliable feedback on that. Judging by the pictures on the NY Jbodies 2200 page, the change in location of the crank sensor notches should change the reference angle. Some ignition questions weren't resolved.ĭIS ignition reference cnage for the pre 98 crank is definitely 60 deg BTDC.