Performance tuning the Nissan Sentra Engine Tuning
Today, I decided to try and check the timing because I am certain it hasn't been checked ever in its 12 year run, until now! Here is a write-up on how to do it. This will make the idleing smoother, engine run smoother, as well as perhaps increase gas mileage for having the optimum timing.
When I checked mine, to my surprise it was at 5 degrees BTDC! No wonder my idle was fluctuating, despite cleaning out the IACV valve, and having new plugs. Not to mention when flooring it, it didn't feel THAT smooth ( I wanted it to feel smoother) and I guess you can say it didn't quite rev easy.
Maximum allowable is 15 degrees BTDC, but you must use 91 or higher octane gas!!!! If you hear pinging or detonation, RETARD THE TIMING to prevent engine damage. According to Nissan Performance Mag in the "Ask Sarah" column of the November 2002 issue, maximum allowable under 87 gas to get slightly more horsepower is 12 degrees.
1. Warm Engine up
2. Turn off car disconnect fan
3. Disconnect Throttle Positioning Sensor
4. Connect Inductive Cable to Plug #1, Connect Postive and Negative Battery Cables
5. Loosen Distributor Bolts
6. Restart engine, rev 3 times a little bit over 3000 RPM
Be sure to reconnect the TPS and the fan connector once you are finished!
Did I notice a difference? YES! Idle stablized even more, and it runs a lot smoother. I notice myself shifting over 15 mph 1st gear, 25 mph second gear, without thinking as if I do it automatically. Before I would shift at those just because.
Engine doesn't sound strained either. Revs freely as well. I personally believe I have gained some low-end torque. I accelerated faster on a hill on the freeway which I would normally step on the gas and not see a noticeable speed increase. But now I do. Hopefully I can notice some better gas mileage as well (or worse, haha, and not that I didn't have great gas mileage before)