Trouble starting, need help
Trouble starting, need help Keep in mine this is a fresh build with 0 street miles, just some idle time in the driveway. 2 days ago my car started acting up while starting. It barely wanted to crank over. Then the nose of the starter broke off, so today I replaced it with a new LT4 starter. It cranks fine but unless I give it gas and hold it around 1K for a few seconds it dies. Idle is now around 700 or so and it is throwing a P0300. Fuel pump is new as is the filter, plugs, wires and opti are all new. 2 days ago it idled fine around 800 with some surge to 1000 due to just having a baseline tune. I am running the racetronix kit without the hotwire hooked up, could that be causing the pump to not get enough power to pressurize the system? Anybody have any ideas?
Last edited by hitmanws6; Oct 5, 2010 at 11:51 PM.
P0300 is random misfire, no cylinder specified. Double check plug wire boots are tight, especially coil wire? Test the resistance on the coil if that doesn't get you anywhere http://shbox.com/1/coil_testing.jpg. You can also have the ICM tested at Autozone; have them run the test several times back to back so it gets warm enough to show a problem if there is one. Start with making sure spark is good and see if that fixes it.
The coil wire actually wasnt on all the way, fixed that and still nothing. The ICM would make sense, I replaced the coil less than a month before my last motor went, Ill have it checked though. The ICM is still OEM. Would that explain why on a cold start its fine but after its been ran it has a hard time?
If it's original and you haven't done the ICM cooling mod, it certainly could get finicky when it heats up. That's the main reason I suggested repeating the test at the parts store enough times to heat it up and see if it fails. And you didn't find any other wires that needed to be burped at the opti or plug side?
MAF looks good? Did you set the TPS position/ check its output? No missed vacuum accessories, etc. creating a big leak? Just brainstorming for things to double check...
MAF looks good? Did you set the TPS position/ check its output? No missed vacuum accessories, etc. creating a big leak? Just brainstorming for things to double check...
Thought of one more thing that might be a good item to cross off your troubleshooting list- idle reset (IAC):
http://shbox.com/1/4th_gen_tech2.html#iac_reset
(IF you can get it to run for 5 seconds after starting)
You can also pull the IAC motor out of the housing and see if it moves (might need a buddy for this) when you turn the key to acc. on (KOEO). If it's stuck at the end of its travel it might keep you from holding an idle at all.
http://shbox.com/1/4th_gen_tech2.html#iac_reset
(IF you can get it to run for 5 seconds after starting)
You can also pull the IAC motor out of the housing and see if it moves (might need a buddy for this) when you turn the key to acc. on (KOEO). If it's stuck at the end of its travel it might keep you from holding an idle at all.
