Died at the lights

[KBurgoyne]

The idle started dropping at the lights and it dies after a few seconds. Cranked for 10 seconds and it came back to life. No loss of power. Drove it around for a while, everything felt normal and couldnt get it to die again. any ideas? It has an airdog 150 system. As far as i know fuel solenoid is original. Its getting dropped off in the morning for a look over.

 

[DavidC]

Probably would help if you let everyone know what your talking about, truck (year etc.),lawnmower,weed eater

 

[KBurgoyne]

whoops. Dont know what happened to the sig. 95 Dodge r3500, 12valve. 240k miles. Mostly stock, only fuel upgrades are #6 plate and injectors. Run like clockwork since the airdog was installed. This was the first hiccup in 50k miles.

 

[BigPapa]

Definitely sounds fuel related.

May I ask why you went away from the rock solid dependable stock lift pump to the Airdog?

 

[KBurgoyne]

The factory lift pump died, and i had already had a few air leaks in the system.
I'm guessing the solenoid is dying or a hunk of crap got stuck in the filter. It was at less than a quarter tank

 

[Joe Mc]

Silly question but do you have a fuel psi gage???

 

[KBurgoyne]

I dont. The solenoid has been replaced and im waiting on replacement filters for the airdog. had everything looked over by a shop. no leaks, no codes. searching the forums, it looks like a crack in the pickup tube can do this if its low on fuel which it was. There are a hundred slightly different stories about start/stop fuel system gremlins.

 

[DavidC]

Definately pays to have a pressure gauge. Takes some of the "what is it" out of the picture

 

[Joe Mc]

You could put a gauge on in engine compartment temporarily just to see what's going on to help troubleshoot.

 

[GAmes]

I dont. The solenoid has been replaced and im waiting on replacement filters for the airdog. had everything looked over by a shop. no leaks, no codes. searching the forums, it looks like a crack in the pickup tube can do this if its low on fuel which it was. There are a hundred slightly different stories about start/stop fuel system gremlins.

You won't get any codes, nothing in the fuel delivery system is monitored. A cracked pickup tube is highly unlikely. What rpm is your idle set at? Manual transmission or automatic?

 

[KBurgoyne]

Its a manual. rpm at idle is between 600-750. 750 in the morning when its cold. 600 when it gets hot. I know how to up the idle but i dont think it explains why it took 10 seconds to crank back to life while feathering the throttle. It acted like the fuel supply was cut off.

 

[GAmes]

It only died once, correct? The low idle speed is a likely reason. Most 12 valves idle speed increases when the engine is at operating temp. It is odd that your idle speed is higher when cold. Adjusting the idle according to the FSM spec costs nothing and might be all you need.

The fuel canister is designed with a "basket" that holds fuel when the tank level is low. When the fuel sloshes back and forth while starting/stopping or climbing/descending hills the basket stays full. For that reason I doubt that a low fuel level was the cause.

Worst case is the high dollar lift pump is intermittent. The good news is that if there is failure it won't kill the injection pump.

 

[KBurgoyne]

Cold air that is. It idles a little higher when its cool and humid. Always has. Its been a hot/dry year. The new filters should be here in a few days. In the mean time ill bump up the idle. IS 800 with AC on correct for the manuals as well?

 

[GAmes]

750-800, engine at operating temp, AC on is the FSM setting. I set mine to 900. Better when in stop and go traffic for AC coldness and heat in the winter.

 

[Dl5treez]

Possibly the return regulator.