Hello i was driving and the engine stops running he gives a error code P1688.
We helped him to spray some stuf in the air filter and he runs a few seconds and he stops again.
Can somone help me what the problem is?
It's a 3500 diesel cummins tow truck.

Regards people from Holland

 

Looks like bad news my friend. Sorry.
See this thread...
http://www.ctd-resource.com/dev/show...threadid=58645

There are some others..

 

P1688 is Internal Fuel Injection Pump Controller Failure. It will take a new IP to fix it, also I would check the lift pump. More than likly it went out and starved the IP. Get an incab fuel pressure gauge to monator the lp. this is a very common problem in the 98.5 to 02 24v trucks.

 

Stop spraying stuff in the air filter to get it going. Your engine does not have glow plugs. it has a grid heater that heats the incoming air instead. if those heaters cycle on, theres a good chance what your spraying in there can ignite and cause some serious damage.