my cold start relay clicks on and off for about 45 seconds and truck seems to start hard is it bad?

 

What year truck? There's a couple of different relays that have to do with cold weather. Both GPR & IAH (on some models). The GPR (glow plug relay) should click and stay on for up to 120 seconds when the key is turned on. If yours is cycling on and off, it should be changed. Check the voltage with a meter. One large post should show battery voltage all the time. The other large post should show voltage for up to 2 min. only after the key is first turned on.

 

it is a 93 idi

 

I don't remember much about the IDI. We do have an IDI diesel section located further down the main forum listing. You might try asking there. I don't know if the 2 minute rule would apply to the IDI.

As a general rule, if you're having lots of white smoke while cranking, and even more when you finally do get it started, then you do have a glow plug or GPR issue.

 

A 93 IDI will glow the plugs for up to 15 seconds, then on and off for another 25 ( afterglow). If your wait to start light only glows for a few seconds on a stone cold engine, you have glowplugs out. Go down to the 6.9/7.3 IDI section, they have LOTS of posts that help diagnose glow plugs. (at least those GPs are on top of the engine instead of under a valve cover.)

 

the first start of the day my glow relay works fine and fires right up but the glow relay will not relay again untill engine is cooled off. sometimes when engine is still a little warm the light wilol stay on for few seconds but wont get as good of start as when it is cold. what could i do to diagnose this problem?????

 

It doesn't need to glow for the whole time when the engine is warm. Are you having starting problems? Your '93 has the better glow plug system. If you have short glow times, you have plugs that are not working. Check them with a 12v circuit tester. Touch the top of the glow plug and the other end of the circuit tester to the POSITIVE terminal on the battery, if it lights, you have a good plug. Glow times with a cold engine should be 8-15 seconds depending on outside temps.