DIYPNP starts then stalls when warm
#1
DIYPNP starts then stalls when warm
I have a 95 with a 1.8 that has had a DIYPNP on it for over a year. I just installed new flowforce injectors about 9 months ago. I have noticed that the car seems to start and run fine until I drive it to the store or something quick. After about 10 minutes of sitting in the parking lot, I will come back and start the car and it will start, and then stall immediately. It will do this until I give it throttle for a couple of seconds and then it is fine. Subsequent starts are no problem unless I let it sit as described. I have logs of the car doing this and have played them so many times, but can not find anything strange except the AFR, but I think it's lying to me because sometimes it says 7.8 before and after starting the car for about 10 seconds and then picks up the actual readings.
I had no problems that I could remember in the cooler months, or before the injector install. The reqfuel calculations are correct as far as I know, and I've tried messing with the ASE, and disabled the MAT during ASE - nothing seems to make a difference. Can someone point me in the right direction?
I had no problems that I could remember in the cooler months, or before the injector install. The reqfuel calculations are correct as far as I know, and I've tried messing with the ASE, and disabled the MAT during ASE - nothing seems to make a difference. Can someone point me in the right direction?
#2
Retired Mech Design Engr
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More ASE, for longer taper at 180* CLT and up. Taper must be long enough until the EGO can help control AFR. As you noted, it takes some time before the WBO2 sensor is working (I'm guessing an Innovate brand). I'm using 1100 cycles ASE Taper at high CLT.
Also, add a longer time to the transition from Start to Run IAC percent, if that is possible with an MS2. This will hold the RPMs up after the start in order to let Closed Loop Idle engage. Otherwise, the lean mixture will keep the RPM's too low for CLI to come into play. 3 seconds should be enough.
Lastly, have at least 10% EGO authority in the idle range.
Also, add a longer time to the transition from Start to Run IAC percent, if that is possible with an MS2. This will hold the RPMs up after the start in order to let Closed Loop Idle engage. Otherwise, the lean mixture will keep the RPM's too low for CLI to come into play. 3 seconds should be enough.
Lastly, have at least 10% EGO authority in the idle range.
#5
Boost Czar
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look at his log, his ait corr% is 77%. even if you gave EGO 10% (I actually used 15%), he's still be injecting 13% less fuel...
obviously his MAT based corrections are actually incorrections.
#6
Retired Mech Design Engr
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Scott,
I agree. I also admit that I did not look at tune, assumed general correctness, and then presumed that the issue was injector heat soaking, rather than MAT issues. Looks like MAT correction setting in 3.4.2 on MS2 is same as newer MS3, which is good, if set correctly.
I agree. I also admit that I did not look at tune, assumed general correctness, and then presumed that the issue was injector heat soaking, rather than MAT issues. Looks like MAT correction setting in 3.4.2 on MS2 is same as newer MS3, which is good, if set correctly.
#7
For now, the hot start issue is solved by really jamming up the ASE and Taper. In the future it'll be done with a correct tune and and an adjusted MAT.
Thanks for the kick start!
#10
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Can you post your ASE curve and taper? Having hot start issues here as well. Think I've got an idea of what they should look like but just was curious what worked for you.