Engine/Transmission (1998.5 - 2002) Rough cold start

[klcammie]

When truck sets 12 hour or more in 30 degree or colder it starts, idles rough and throws a 1690 code. after about 1 min it smooths out and runs good. If it;s plugged in no rough start. Less then 12 hr it doesn't have any problem. Any ideas?

 

[WalterRyan]

It sounds like the heaters themselves might be bad although P1690 sounds like it could be related to the injector pump.



I have not heard of the heaters commonly going out but Cummins Northwest did have plenty in stock so it might be more common than I know.

 

[BIGNASTY]

I made a post about the same thing on my 3rd gen got lots of looks but no comments. I called a Cummins Mechanic in So Ca that has done some work for my son on his 3rd gen. I told him about the symptoms like yours mine had to sit for a week before it would act funny upon start up. He told me to check all the fuel filters that I have to make sure no air leaks and check all fuel lines. But he thought that the problem would be in the fuel line connection at the CP3 it has those round washers like gaskets that are encircled by metal. and one on that would be the problem. Sure as Hell it was, replaced it and runs like it did when new and its got 98K Mine threw no code but it stumbled like it was not getting fuel.

 

[klcammie]

Thanks for the replies. The heaters are working checked the wires plus the volt gauge shows the draw as they come on. Will check the filters and plumbing for leaks tomorrow. I just recently changed the filters maybe something is loose.

 

[hcole]

When truck sets 12 hour or more in 30 degree or colder it starts, idles rough and throws a 1690 code. after about 1 min it smooths out and runs good. If it;s plugged in no rough start. Less then 12 hr it doesn't have any problem. Any ideas?

Try parking it downhill so if it is a leak on the upper part of the engine, it is less likely to drain back to the tank.

 

[BIGNASTY]

Try parking it downhill so if it is a leak on the upper part of the engine, it is less likely to drain back to the tank.

I think that would work but I think that more than a visible fuel leak (which is what I noticed upon a closer look) would be an air leak. When I really got down to taking mine apart I steamed the area around the pump and let it sit in my shop for a day. When I took it apart I wanted no chance of dirt contamination. Before I steamed it I looked very close at it and there was a sign of a small fuel leak more of a wet spot than an outright leak. I could not tell for sure about this because in MT its winter and road grime and wet conditions abound. When I did get it apart I found the mentioned washer/gasket had a little wrinkle in it. I use some silicone spray on a finger when I put it back in and thought that it might help not putting it on dry. So far so good.

BIG

 

[klcammie]

Try parking it downhill so if it is a leak on the upper part of the engine, it is less likely to drain back to the tank.

Thanks, will try parking facing down hill next week when I go to work. Will let you know what happens.

 

[klcammie]

update to rough start

Tried parking uphill and down hill, no change, if truck sits 12 or more hours in temps below 30 degree I get a rough start and a 1690 code. I even tried cycling key 2 or 3 times.

 

[Vaughn MacKenzie]

Does it throw a cloud of white smoke during the rough starts?

 

[klcammie]

Does it throw a cloud of white smoke during the rough starts?

No it just a little rough the tach moves 50 rpm or less for about 5 seconds then MIL comes on. Then truck smooths out and no more trouble. I clear code and am good till next 12 hr sit in colder then 30 degree. If plugged in then no trouble.