hard start when cold

[bigfoot]

Hi everyone - been lurking for three years, finally posting a question. i have a 93 na with 121k. been a great truck. now it's cranking a LONG TIME before finally starting, even with the temps in the 60's. Plug it in for a few hours and fires up right away. New starter, gp's, return lines and injectors. turn the key, the wts lights up for 15 seconds. dims the dome light just like it should. starter spins nice and fast. I want to convert to manual gp switch. any guesses on whether that will solve the problem? other ideas?

this is a great site. I've learned a lot!

 

[tbrumm]

I see you have replaced your injectors and return lines, but what about the injector pump? If the pump is original, it may be getting toward the end of its life and it may be time for a rebuild. If all other systems are working properly (good batteries, good cables, good starter, good grounds, good GP controller, good gp's, no air intrusion, etc.) the hard start when cold may be pointing toward a weak IP. Did you time the truck after the injector replacement? Making sure the truck is properly timed will help with starting too. The timing advance on the IP also needs to be working properly to help with cold starts. I know many prefer the manual gp switch, but when the gp system components are in good condition, the factory setup does work well in my opinion. How is the condition of the gp wire harness and the individual connectors at the gp's? I am sure those with way more knowledge than I will also respond and help.

 

[bigfoot]

I think the IP is still good - no problems on long summer trips over mountain passes with the camper on. Lots of power, and hot starts are perfect. But I do plan to put a new IP on next year. How do i check the timing advance? I am also suspicious of the GP harness. Power to each GP - suggestions? thanks for any help

 

[franklin2]

I had trouble with my GP harness. But when I had the trouble, the controller would short cycle. So I knew when it was not going to start. I found out all I had to do was take the wire off each glowplug and stick back on, and it would be good again for another couple of weeks.

I did go to manual glowplugs after this. The truck will start with several glowplugs not working IF you have a manual setup. If you are using the controller it will short cycle and not start with only one bad glowplug, or a poor connection somewhere in the gp harness.

I don't know what to tell you though. If you are getting a 15 second cycle time from the controller, then it and the glowplugs are working.

 

[tbrumm]

http://www.oilburners.net/forums/showthread.php?66482-Winter-is-here!-Thoughts-on-cold-hard-starts

http://www.oilburners.net/forums/showthread.php?66851-Correct-Voltage-at-glow-plug-connectors

Here are links to a couple of threads that might prove helpful.