hard starting when cold

[allgonoshow]

2001 cummins is hard starting when cold. This is a pretty dumb question but how long should the manifold heater stay on when it is below 32 degrees. It will start fine when plugged in. When it is cold and not plugged in it will crank and fire 2 or 3 times before it will run, when it finally will take off it runs roughly. Sorry for the newb question but I am new to 24v cummins, thanks for the help.

 

[argve]

are you sure the grid heaters are working? sounds like they aren't.

 

[Black dawg]

x2 on the heaters. Ive seen 2 24v trucks with bad computers, one wouldnt turn the heaters on, and the other wouldnt turn them off.

 

[allgonoshow]

Yeah I checked and I have no power going to the manifold heaters. I have constant power on the solenoids but none going to the manifold when I turn the key. It does have an edge 5 stage programmer on it. What do you guys think it is? I looked for a relay or fuse for the manifold heater but did not find anything...thanks alot for the help guys.

 

[allgonoshow]

So what do you guys think???

 

[argve]

what condition is the "trigger" or control wires and connections on the solenoids in (are they good clean and tight?) Don't know how many miles you have on her but wires do corrode and can break back in the insulation where you can't see them right off.

If the wire and connections look good then go back to any connectors that they pass through and check those - keep working your way back until you get up to the ECM.

On my 95 the ECM made a decision on how long to run the grid heaters by looking at the outside temp - which on mine was taken under the battery on the drivers side if I remember correctly. Might check and see if there is a problem with the outside temp sensor. I'm guessing the truck uses the same sensor to display the outside temp on your overhead as it does for grid heater cycle time. Or I would assume it does.

If I'm not mistaken I think your ecm is mounted on the drivers side of the engine block tucked under the intake manifold sort of behind injection pump above the fuel filter area. That's a nasty area for wires to live in if you ask me that is why I mentioned checking the wiring. Because after 9 years of life they have seen some pretty nasty times.

 

[allgonoshow]

The wires all look to be in good shape. Interesting point on the temperature sensor. When I tried to start it the other morning I saw that the temp on the over head read like33 degrees, but I know damn well it was colder than that. I wonder if that is the problem...thanks again for any help.