Ok here's where i am at with my 1987 GT Stang. I run NOS on this car and everything was going well when i ran 100 shot with 4 degrees retard. I did some other mods to car (Not Engine / its Stock) and today i went to a 150 shot with 5 degrees retard and it seemed as if i now have a few problems. After some what of a short test run, my car seemed to want to stall at 200RPMS and so i took my time and got home and ran codes on tester. The codes i came up with are / 81 - air diverter solenoid fault / 29 insufficient input from VSS / 34 - Insufficient EGR Flow, EVP voltage high, FPE sensor Voltage high / 66 - VAF, Mass Air Flow Sensor Fault, Below Min Voltage / 87 Adaptive fuel limit reached, Fuel pump primary circuit fault. HELP ME PLEASE. by the way the pump is only 3 months old and a 255lph pump, 24lb injectors & C&L MAF calibrated to 24. I Have been suspecting problem with VSS as i would stall sometimes when braking and gearing down. I really need all the help i can get.
Important info needed. Are you using A Dry Nitrous System or Wet? You can disconnect the MAF Sensor and test drive it. Follow link for testing MAF. USE A/C delco R42TS Plugs. With a 150 shot dry and less than 94 octane you may have melted a plug. Pull all of them and check them. If the bogging of the engine only happened after you put 150 pills in it. Switch it back to 100 shot pills and test. If it still boggs, make sure your NOS Solenoid is working (disconnect fuel solenoid and hit button with engine off) It can bogg as if you are just adding a bunch of fuel and no nos. Make sure bottle is full and open(you would be surprised) I have also seen holes in the nos line that can cause the same Bogg from not enough nos and too much fuel. Double check the 150 pills and make sure you put the right ones in the right spot. I ran 150 Dry for 2 years on stock engine with no issues, to go more than that the block will need to be replaced. I have also ran 150 wet on a stock engine with no issues for years. Key is to have High octane(Add Octane Boost for cushion) and correct timing. Factory timing is 10 with chip removed. You should be able to bump it to 14 before taking timing out for nos without worry of backfire/pre-detonation/engine ping. On a wet Nos kit, I would set timing to 8 and for dry I would leave it at 10. On a wet Nos kit, I would set timing to 8 as long as you have 92 octane fuel with 8 point octane boost added ( you can by octane boost at any auto parts store) If you spin real bad, you can retard timing to 4 and it won't spin so bad. Not sure if you are running D.O.T. s or slicks. If you are not allowed to use Octane boost than set timing to 6 but you still must use 92 octane or higher.