Hard starting when warm
#1
Hard starting when warm
I searched some but didnt find what I need. After I put in my injectors(38lbs per hour) & fuel pump(walbro 255) my car wont start after its been ran for awhile without giving it gas. What tables should I change and in what way using HP Tuners?
The car is a 2001z-28 a-4 with a TorquerV.2 cam, exhaust, underdrive pully, etc...
Thanks in advance for any help.
The car is a 2001z-28 a-4 with a TorquerV.2 cam, exhaust, underdrive pully, etc...
Thanks in advance for any help.
#2
Probably isn't getting enough airflow during start up. Check under the idle section for any startup friction airflow correction tables. IDK what HPT calls it. But, there should be a table somewhere that adds in extra airflow for startups. Increase it a little around the temps where you're seeing problems (3~5 grams/second). There was some debate over the temps. My software reports this table as refering to IAT. However, some other software suites report it refering to ECT. I believe IAT is right...
#4
The cam has really bent your cranking VE and the
injectors may also be contributing to a low end fuel
error (offset at least, maybe minimum pulse width
as well). All making the setup less tolerant of fuel
to the rich side, and cranking throws some heavy
enrichment. No good way to tune the cranking VE
table, so most people leave it stock, but that is
going to leave a high airflow (hence rich) error.
Blind stab is your only tuning option and quit when
it starts to yelp.
High soaked IAT / ECT also contribute a speed density
airflow error, this is probably the final straw for your
hot starting. It seems like the temp effects model is
really sloppy. Some people play with the charge bias
value and see fortunate results; I've been trying to
understand this but there's too much uncorrelated
jibber-jabber mussing up my mind about how the temp
affects mixture calcs. You could try it though.
injectors may also be contributing to a low end fuel
error (offset at least, maybe minimum pulse width
as well). All making the setup less tolerant of fuel
to the rich side, and cranking throws some heavy
enrichment. No good way to tune the cranking VE
table, so most people leave it stock, but that is
going to leave a high airflow (hence rich) error.
Blind stab is your only tuning option and quit when
it starts to yelp.
High soaked IAT / ECT also contribute a speed density
airflow error, this is probably the final straw for your
hot starting. It seems like the temp effects model is
really sloppy. Some people play with the charge bias
value and see fortunate results; I've been trying to
understand this but there's too much uncorrelated
jibber-jabber mussing up my mind about how the temp
affects mixture calcs. You could try it though.
#5
I had that same problem awhile back with my GMC Truck. Turned out to be the fuel pressure regulator. Maybe it's not a tuning problem at all...maybe it's a part? Any misfires or crappy idling?
#6
Thanks guys i'll look over that stuff once I get home from work.
pdanrichey- the car idles fine from cold start, and after started warm. It's just I have to give it a little gas when warm starting.
pdanrichey- the car idles fine from cold start, and after started warm. It's just I have to give it a little gas when warm starting.