geoff17

Ok I've done a ton of searches and still haven't really found an answer. I just finished up my lq4 swap into a foxbody mustang but can't get it to start. I'm using an 04 lq4 out of an express van with a 4l80e. I am running the stock ecm which has the blue and green connectors. I had a custom harness made for me by current performance wiring. Anyways I finally put some gas in the tank and filled up the rest of the fluids in it last night and primed the oil pump then put the fuel pump fuse back in and it started and ran for about 3-4 seconds then died. Thinking nothing of it I tried again and ran for about 1-2 seconds, and then anytime after that couldn't get it to start only try for split second every now and then. So I started to do some investigating and confirmed I had fuel pressure, then tried adjusting fuel pressure anywhere from 30-60psi. Still nothing. Pulled all the plugs, they looked fine. Grounded a plug while cranking and confirmed I have spark. Also put a light noid in the injector wiring and confirmed I have injector pulse. So I have air/fuel/spark but it won't run. Checked grounds, all seem fine. Even temporarily ran a ground from the drivers head to negative post of battery and no change. I have no way of reading the ecm since I have no software or even code reader. The ecm has a base tune it for my injectors and supposedly has the VATS disabled and also tuned to run without a MAF in SD. Anyone have any ideas on what else I should be looking for?
Thanks in advance for any help

geoff17

got it figured out posted my results in my other thread also, but I just swapped out the 1 bar map sensor for a 2 bar map and it ran fine.