Hey guys, I've been tuning my truck for about a month now. It used to have a 4.8l and now it has a 402. I started with a stock 6.0 tune and have got it pretty dialed in (I think).
My problem is when slowing down and coming to a stop, I have to fight the truck to slow down once it gets to around 30-40mph. I've read about this a little bit and see that it is somewhat common with a cam change. I have tried zeroing out the entire throttle cracker table and it didn't change, messed with timing a little bit but noticed nothing significant so I changed it back to the way I had it (where it is now).
The info is in my sig, but here it is again incase you are reading this later on. 402ci, 42# racetronix injectors, 9.1:1 comp, 224/228/112 cam. It has electronic throttle too.
Is this timing related or DFCO related maybe? It is not pulling very much vacuum at all on decell, should it? The TPS doesn't go under 19% until I am totally stopped. Then it drops down to around 11% sometimes. Once the mph reads 0, it idles perfectly. In a city driving situation, the timing seems to go up and down a lot in big swings and the truck sort of surges along with it while slowing down and off the throttle. And should I be going into DFCO more often when I let off the gas? It takes high speed and high rpm to actually get a lean wideband reading.
At the end of the log is when you can really notice it. I did WOT and then coasted from there into my driveway.
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