fred81292

I have a 5.3 that won't start on it's own unless you spray some starting fluid in the TB. It will stay running and runs fine. It just will not start with the injectors. I am getting the proper fuel pressure. It's a 2005 with dbw. The ECU has been tuned to delete vats and emissions and some other adjustments. Has anyone else ever had that problem?

JoeNova

90% of the time this happens, VATS wasn't properly deleted. Pretty common here.

Get a noid light to make sure that the injectors are firing.

fred81292

I'm pretty sure it's deleted. I sent it to the guy from lt1 swap. It will stay running and idle and the throttle works. It just need starter fluid for the initial start. Then the injectors take over.

G Atsma

Not getting enough fuel/air to start? Dumb question, I know, but it needed asking.

fred81292

Don't know. Mass air flow is working. It's detecting temperature in my scanner. I saw a post where someone has the same problem but he was cable so he had individual tps and iac sensors. Something was wrong with his tps so he unplugged it then it started right up. I'm dbw so it's in the throttle body. But I'm now getting any codes in the scanner for anything to keep it from firing

G Atsma

I'm not sure the MAF is need to start, as there is so little air moving on startup. I have a feeling it's in the tune.

Old Geezer

iTrader: (3)

I'd be looking at, too.
If vats is on, the engine would not continue to run.

fred81292

So what would cause that the air fuel mix to be off? I have the MAF hooked up to a cold air filter hooked directory to the throttle body temporarily. I am assuming it works cause I can blow warm air in it and the temp goes up on the scanner.

JoeNova

Until you determine whether your injectors are firing while cranking, anything you do is just speculation.

fred81292

I did last night. There's no pulses on cranking. I'm getting switched 12 volts on the pink wires. So they're getting power. I dont have exhaust or the radiator hose installed yet. So I didn't run it long enough to check them when it was running. But I know there's no pulses on ground when cranking.

JoeNova

Check all of the ground wires in the PCM. See if your scanner is reading TPS.

fred81292

I'll double check the grounds at the PCM. The throttle read 19% closed yesterday if I remember correctly.