First fire up...runs but dies and won't start.
Thread Starter
TECH Fanatic
Joined: Oct 2011
Posts: 1,425
Likes: 0
First fire up...runs but dies and won't start. Okay, after 3 months I finally was ready to fire it up. It fired right up and runs for about 3 seconds and then dies. When I try to start it again, it won't do anything. This is with the battery on a charger. It sat for 3 months so I am thinking the battery is dead. I am going to charge it all night and try again. What I want to know is once is starts shouldn't it keep running on the alternator or is it that I just don't have it running long enough to switch from battery to alternator and that is why it is dying.
Also, what pressure should I have my fuel pressure regulator set at for starting it and just idling? I tried 30, 40 and 50 psi. It seemed to run the best at 30 psi...at least it sounded like it did. Really too short to guage anything. It is on E85 and 160lb injectors. I had the pcm tuned for E85, injectors, etc... but just to get it running to get it to the dyno. If I weight about 5 minutes while it is on the charger it will fire again and run for a few seconds and then it won't fire at all the second time.
Also, I turn the fuel pumps on with a toggle switch and don't try to fire it until it is up to pressure. Probably run the pumps for about 3-4 seconds.
I am thinking not enough juice but wanted to see what you all thought and any ideas I could try.
Also, what pressure should I have my fuel pressure regulator set at for starting it and just idling? I tried 30, 40 and 50 psi. It seemed to run the best at 30 psi...at least it sounded like it did. Really too short to guage anything. It is on E85 and 160lb injectors. I had the pcm tuned for E85, injectors, etc... but just to get it running to get it to the dyno. If I weight about 5 minutes while it is on the charger it will fire again and run for a few seconds and then it won't fire at all the second time.
Also, I turn the fuel pumps on with a toggle switch and don't try to fire it until it is up to pressure. Probably run the pumps for about 3-4 seconds.
I am thinking not enough juice but wanted to see what you all thought and any ideas I could try.
For starters, I'd contact whoever did the tune and ask them what rail pressure it was tuned for. Was it 43...or 58?? My guess is that it's running pig rich and dying/flooding out. What is your wideband reading while it's running for those few seconds? I believe e85 is stoich at 9.8??? I can't remember for sure.
sounds like a very dead battery. also are you sure the alt is working? how to tell is to put a voltmeter anywhere on the car and when it is running it should say 14 volts if the at is hooked up right and working.
sounds like vats is not disabled to me. Is your security light flashing? If your vehicle thinks there is a theft it disables fuel injector pulse within a few seconds of start up and causes it to die.
Thread Starter
TECH Fanatic
Joined: Oct 2011
Posts: 1,425
Likes: 0
I got it running now. It seems as though everytime I start it it runs better and longer. It will run until I turn it off now but the idle is very high. Somewhere around 2k. I don't have a tac hooked up yet. The tune is set for open loop and I don't have my LM1 hooked up yet. All I am trying to do is get it running enough to get it on the trailer. It will be driven less than 50ft. I am thinking with the modified harness the computer is learning and making adjustments everytime I start it. If that makes sense. I may need to just let it run for a while. With it cold out I am wondering if the IAC is keeping the rpms up because of the cold. I will try to post a video in a little while.
