Wont start when warm. ?
 

This is HP Tuners SD 2-bar op system. Turbo car on E85.

When cold it starts instantly. After driving around and shut it off..... it wont start again untill it has cooled. Once its cooled awhile (not completely cold) it starts and then idles really low at 400rpms for a few seconds and then slowly comes up to idle at 1100rpms. Then it is fine idling.

Is there a table somewhere that alters somthing based on temp? I zeroed out the IAT table I know the intake pipe gets heat soaked when it sits there off. So that shouldnt be it. ??

Scan it when this happens??

Yes. What do you need to know? Ive tried adding more timing, added and subtracted fuel. Watched the A/F at cranking, idle... tried it in various spots from 10:1 up to 14:1 It still does the same thing once its warm regardless.

Its hard to monitor the A/f when cranking. Not sure how accurate it is since the exh gas is moving so slow thought the pipe. I have 160# high imp injectors. I know that idling around 1100rpms im seeing about 2.5ms injector pulse and that is as low as they go really. A/f at that is about 13.5:1 But when I crank it im seeing inj pulse of like 4.5ms. So I know that its dumping in the fuel. I lean it out in the cranking VE table.. and it wont start at all then or even fire. When its dumping the 4.5ms in it pops and slowly starts when warm sometimes. ... the 400rpms for a few seconds then comes up. Starts fine when cold.
4.5ms seems like a lot of fuel, im not sure if im overlooking some table somewhere??

Look at the indicated IAT just before cranking. It is
crazy enough in a stock NA car when the IAT heat-
soaks, on a turbo with the extra heat, ???. Makes
the air calculation way off (low) and the effective
mixture too rich.

Relocating IAT made a big difference for me. May
not be the right thing to do for a turbo SD setup
though. You might want to play with the startup
fueling tables, anything based on IAT you can
find.

I know that after you shut it off and it sits for a minute the charge pipe going into the throttle body is hot to the touch....very hot. Turbo is right below it about 6". I couldnt find any other table other than a timing retard table that is affected by the IAT.... do you know what other ones there are?

Adding LOTS of startup airflow in the warm cells along with more crank enrichment usually helps with E85 warm starts. Even then my GTO can be a pain sometimes with long cranking but my Camaro is great.

Under the fuel control table go to open/closed loop tab. From there open the top left table under open loop that says EQ ratio. The numbers you see in the table are enrighment factors depending on coolant temp. The PCM adds more fuel to a cold engine vs hot engine based on this table.

If you have a wideband O2 in the car and it shows the car running too lean on the hot starts, then adjusting this table closer to 1.0 in the colder cells (and then resetting your VE and base running airflow tables accordingly) should smooth things out. :)

he needs a table that is EQ vs. IAT. moving the iat will help. i tested mine by having another iat out side of the engine bay and hotstarting with both and it was a world of difference. are you spraying meth at the iat?

What about the after start enrichment table IAT vs. ECT multiplier? Its all zero right now. WEhen you crank it now it wants to but dont stay started.... would that kick it in and help? What would you set it to? Obviously I know the temps to do it at but what number value?

month later... car still wont start when warm......tttttt.

IAT upon trying to start reads 102 degrees. That table is zeroed out anyway. Cant really scan/log a cars starting A/F mixture when it doesnt run.
When its cold it fires instantly, and as it warms up it progressively starts harder. When its semi-warm it fires slowly then idles really low barely wanting to run at like 400rpms.... then after 10 seconds it comes up and idles fine.

Ive played with the afterstart enrichment a lot... no luck... no change. Ive watched my WB go from when its struggling at 400rpms at 10:1 A/F and the same when it says 14:1 ...... So adding subtracting fuel makes no difference... it still idles really low struggling then comes up.. and when its operating temp dont start at all.

E85 doesn't want 14:1, it should want about 10:1 for running but something
richer for cold start. Maybe this is just the wideband indication based on a
gasoline assumption based lambda -> AFR conversion. If so then your
10:1 - 14:1 range of experiment is pig-rich to sorta-rich.

The cranking routines sweep fueling and work the rich to very rich
range. Be sure your hot end of the EQ table does not enrich at your
cranking MAP levels. This can conflict with what you would like for
load / boost. If you can't do without enrichment then cranking fuel
multipliers probably want shaved back (working well cold and not
hot, indicates you're rich). At least these don't bug running AFR,
and you may be able to comp out the EQ table values as they are.

Where is this table?



Also when you start it hot, it fires immediately but only runs for 1 second....then nothing. Wont stay running.

Those are just the numbers from my WB... which says the numbers are the same for gasoline as E85... so when it does say 14.7 it is actually is 9.76
If i can get it running it idles perfect around 13.5:1
I added some to the cranking VE table... it fires faster and instantly, but then drops to like 300rpms for 10 seconds still.
What you wrote that I highlighted in red I am not sure what you mean.

EQ vs ECT vs MAP table. At higher MAP you may be more than
1.00 fuel air multiplier. Cranking MAP is probably 100kPa. I have
seen some tables where high ECT asks for a lot of fuel to keep
ping tamped down, this could hurt cranking.

Im not following you here... ?

Also.. would the afterstart enrichment have anything to do w/ it? And if so what is a realistic number to put in that table? I believe it is like .650 now.

This car sits for weeks in between me feeling like working on it. The factory alarm drains the battery. I also have an underdrive crank pulley on. Im wondering if after running a bit (idling because it hasnt even left the driveway yet) that the voltage drops quite a bit even after charging the battery. The voltage offsets might not be right for my 160# injectors to run at a lower voltage....or start ??? Im going to get a smaller alternator pulley and see if that makes a difference.

Anyone know how do shut the factory alarm off on these? (99 TransAm).

When its cold it fires instantly, idles perfect, ....it warms up.....idles and drives perfect...everything is fine. Except if you shut it off it wont start until it has cooled back down.

IAT when im trying to start it hot are at 113 degrees, that table is zeroed anyways.

When you turn the key it fires once and doesnt stay running. When its half way warm it fires and idles at like 400rpms for a 20 seconds or so then comes up.

I have adjusted the afterstart enrichment table high and low with no results. Added and subtracted from the cranking VE table... no results.

My tune is attached. Am I overlooking something? A table somewhere?

Your cranking VE table is very inconsistent with the main VE table,
and it is going to push rich fueling (which cold likes and hot does
not). You might want to begin with making that dovetail with the
main and see what you get.I'd scale the whole thing until the 400,
800, 1200 columns agree (which is a fait bit of shaving, 70s -> 50s).

Your Charge Bias temp table is way off from stock and it biased
toward IAT at low flows, ECT bias (larger fraction) may be more
realistic. If "hot start" ECT is greater than IAT then ECT bias will
lean out the cranking.

Thanks for the info. Turned up the boost a little and logged a few runs.. Tranny didnt like it....Walked home..

After chasing this nightmare for a long time and having zero luck with contacting other reputable tuners and shops and no one knowing what was wrong, or not wanting to help be because of no available injector data for the Billet Atomizer injectors, I sent my tune to edcmat-l1 along with a few log files. After logging it a few times and making changes a couple times, he figured it out!! :nod:
If anyone else needs someone that will not give up and keep helping them when they have a problem and stick with it till its figured out.
Contact this guy. I cant thank him enough for his help.