1974 NTC 350 no fire

[dbs]

Sure sounds like you have a suction leak dbs. That would explain the filter being half full.Could be anywhere from the pump back to the drop tube in the tank.Dont know what setup you have ,I have a 1973 white 4000 with 290 small cam and it uses a remote filter bolted to the truck frame .Also have a 1974 pete with a 300 big cam and it has the filter on the pump.On both trucks at the back of the pump are some capscrews that hold the filter base to the pump like on the pete,and on the white the same screws hold a threaded plate for the suction line the go's to the remote filter base.Got to thinking about this thread today......I might try snugging up the capscrews then work your way back to the tank.I've never seen these screws cause trouble in the past but anything is possible.

I talked to the cummins dealer today he reported the there is a check valve on the pump that can go bad so I'll be checking that to see if that was the culprit.

 

[td25c]

There is a small check valve built in the 90 degree fitting on the back of the pump.It allows fuel to circulate from the gear pump to the return side back to the tank when fuel is not needed such as when the truck is going down hill.My cummins trouble shooting manual also states that if the check valve hangs open it will allow air to enter the suction side of the system.So that could be the problem or a easy place to start looking.Good luck with it dbs.

 

[dbs]

There is a small check valve built in the 90 degree fitting on the back of the pump.It allows fuel to circulate from the gear pump to the return side back to the tank when fuel is not needed such as when the truck is going down hill.My cummins trouble shooting manual also states that if the check valve hangs open it will allow air to enter the suction side of the system.So that could be the problem or a easy place to start looking.Good luck with it dbs.

That's the part I got from the dealer today. I'm going to assume this is the problem and replace it. I'm very interested in the trouble shooting guide you referenced. Could you send me the title and where I might obtain it. Thanks DBS

 

[td25c]

Hopefully the check valve takes care of the problem. My book is titled "Troubleshooting and repair manual big cam III and big cam IV, NT 855 engines". It's a god send for cummins owners,I bought mine in 1989. Might give Cummins a call and see if they have them available . After a search on the world wide waste of time I found this site www.cumminspartsdirect.com/Products/212498-3810298.aspx

That sounds like the same manual. Pretty good book,has a list of trouble symptems then it shows solutions .

 

[td25c]

Thats great you got the cummins fixed dbs.About the troubleshooting manual I forgot to add that it was printed in 1986 and my manual has a bulletin number of 3810298-00 on the inside cover. I noticed the part number of the book at the cumminspartsdirect site is 3810298 so i'm satisfied its the same book.I think I paid around 75$ for mine back in 1989 so 128.28 dont sound bad.Just wanted to pass that along.

 

[dbs]

Thats great you got the cummins fixed dbs.About the troubleshooting manual I forgot to add that it was printed in 1986 and my manual has a bulletin number of 3810298-00 on the inside cover. I noticed the part number of the book at the cumminspartsdirect site is 3810298 so i'm satisfied its the same book.I think I paid around 75$ for mine back in 1989 so 128.28 dont sound bad.Just wanted to pass that along.

Thanks again for all the great info. I actually asked the dealer if they could get me that publication. I don't know how they did it but they shipped it over night no charge and it only cost me $86. The dealer here is very good and want to help even
the little guy. My engine is the small cam ntc350. The manual is very good even though it is written for a later model, many of the parts are similar.