Cummins NHC 250 throttle problem

[area52]

Well, I finally got my fuel lines and other stuff fixed on the M816 wrecker and fired her up for the first time. Cranked a few times and VROOOM!! Idled at about 650 rpm, oil pressure came up to about 30-40 psi. Checked for fuel leaks and it looked good. Noticed air pressure was not coming up so I gave it a little throttle. It seemed very slow to come back to idle but it did eventually(maybe 15 seconds??)

Still no air increase so I gave it a little more throttle and let off- all of a sudden it shot way up in RPM so I jumped out and shut off the fuel shut off valve since I didn't have the cable hooked up and the electric was turned in. NOTHING!! It was still reving very high and I thought it was a run way so I started stuffing the air cleaner inlet and my brother in law who was helping me turned the fuel tank selector switch to the other tank which was empty and it finally died.

So my question is - how long does it take for the engine to die after you close the emergency fuel shut off valve?

I checked the throttle cable and it was all the way closed.

Any hints or things I should check before attempting another start?

thanks

 

[timntrucks]

that happened to me on wrecker. it dont like any air and that is most likely what it was sucking on. once you bleed off all the air it should be ok.

 

[WillWagner]

Sounds like air in the fuel to me.

 

[area52]

So once the air is bled out of the fuel line, the throttle response should be normal and drop back to idle quicker?

 

[scooter01922]

Reassuring isn't it.......just crank her back up. It would scare me a bit too i'm sure. goodluck.

 

[jwaller]

air in the fuel lines. it takes a while to get it out after servicing. restart it and let it run for 10 min.

 

[Lawrence of Arabia]

I have the opposite problem. Had IP replaced a couple of years ago. Started the truck after sitting all winter and I have no throttle. Only idles. This is also in a wrecker. Any suggestions?