So I have been having issues with the idle of my swap (98 LS motor into a 98 GSR shell) and was able to borrow the Autotap setup from a buddy. Below I am showing RPM and the Ignition time displayed - and at idle the timing is at 15° which is good, but look at the dip it takes down to 0°. Is this right? I am wondering if the timing is the problem or did it hit 0° because the motor almost stalled from another unrelated problem? When I rev the RPM and let off the gas it will stall or idle around 400 RPM(barely running). Any insight?



Thanks

 

Is your vehicle throwing any malfunction indication lights ?
When does the vehicle stall ?
Have you done a compression test ?
Have you examined your timing belt to ensure everything is lined up at top dead center ?

 

No codes are being thrown
Car stalls when revving and then letting off the gas quickly
Have not done a compression test
Yes, everything is a TDC

Funny thing is the car will run great sometimes, but others it runs shitty. That fact that is can run good tells me the timing is good. The other thing was when I put the timing belt on there was no way to get the arrows on the cam gears 100% pointing up, the intake was perfect and the exhaust was about .25 tooth off - that was the best I could get it. But like I said, the motor is capable of running good - making me think it could be a bad sensor. Unfortunately the Autotap does not have enhanced diagnostics so I was limited to a very few sensors. I wonder if even the dealer could help me out because this is a swap?

 

Honestly, bud, I'd be more inclined to think that it lost signal when it almost stalled rather than the ECU throwing 0 degrees timing... but if you look at a stock Hondas map you'll see that low rpm, high load will have very low timing values. If the car almost stalls then it will come much closer to seeing atmospheric pressure at the MAP sensor, which in turn will put it into those cells with very little timing.

 

Here are the same (2) graphs (RPM, Timing) but now I added the MAP sensor at the top



So how does the MAP sensor relate to the timing?