Archived Truck won't start

[camnicolson]

I've had an intermittent hard start problem, when it happens the wait to start light does not come on and the lp does not do the normal pre start run. If I tried to start it, the motor just turns over and does not fire up. Normally I just turn off the key, try again and the wait to start light comes on and the lp runs to prime the VP.



On the way home from work yesterday I noticed that every time I idled the truck, the engine was surging up and down +/- 150 rpm. When I got home I shut down the truck and hooked up the OBD 2 to check for codes, none showed up. Since then I have tried to start it and the wait to start/lp problem is continous and the truck will not start.



With no codes to work from I am at a loss. All I can think of is that I have an ECM problem, but I am in Africa and a hit or miss "guess" on the ECM could be expensive.



All suggestions gratefully accepted. HELP!!!



Cheers,

Cam

 

[JFaughn]

Do you have access to a wiring diagram ? with two things not working then that makes me think that its possable that a relay for the air heater and lift pump might be on the same circit and the source is bad like maybe contacts in relay , also ing switch is in there , I think you could find the problum with test lite and a 2nd body to work ing. sw. while your probing with test lite some where between heater relay , LP and ing. sw. and in an emergecy hot wire that circit , but remember the heater takes a heavy load so a fat wire.

 

[camnicolson]

Hi John,



Been away from the computer over the weekend, I have the manual, so will see what I can find, as per your suggestions. Thanks!



Any one else got any other ideas?



Cheers,

Cam

 

[rkressg]

It could be a problem with the Crank Position Sensor. When they die, the engine just flat out quits and will not restart. Also, when they die, no DTCs are set (usually). The ECM also uses the signal from the CPS to control idle, which if failing, could be responsible for the rough/surging idle.



A lift pump that runs eratic to me is a sign of a definate failure. They die in very creative ways, but I think it has just failed. Unplug the lift pump, and check the voltage to it with a volt meter. There should be a solid 12v of power after bumping the starter for 20sec. If the lift pump is dying, it will not run even if power is supplied.



The relay for the intake heater is just below and to the left of the right battery. Look for two heavy wires that are attached to a block. Those do fail, but it is uncommon. Check the intake heaters resistance to see if they are broken.



I seem to remember that if the Wait To Start light does not come, it is a sign of a failed/failing ECM. The light should always turn on. I am not exactly sure on this, but maybe someone will chime in on this.

-Rich

 

[camnicolson]

Rich,



Thanks for the input. I don't believe it is a lp problem, as the pressure is rock steady when it runs. It seems to be an electrical issue. Since my first post I have got it to start by cranking away for 10-15 seconds till the fuel pressure comes up, then it fired up and ran normally. I arrived at the ECM failure idea from the Catcher thread, where the wait to start light, seemed to indicate if the ECM was OK or not.



There is one other CTD out here, so I'll see if I can pull his ECM and then try it in mine, see if that fixes it.



Cheers,

Cam

 

[DavidC]

You could try the system reboot with the batteries disconnected turn the ignition switch on and reconnect batteries. This supposedly reboots the ECM and other systems.

http://turbodieselregister.com/forums/showthread.php?t=123791&highlight=reboot



It doesn't cost anything to try it.

Dave

 

[WVaughan]

I have an 03 with HO a 6 spd. The truck only had 423 miles on it, when it refused to start. Engine would crank over all day but wouldn't fire up. Had it towed to the dealer, and found out that Fuel Injector Booster Pump had failed. Once replaced I haven't had a problem. Hopefully this helps.