I am looking for comments from those of you that use a timing light to set/check timing. I had mine set to 17 degrees almost 5 years ago...at least we think it is at 17. This was in conjuction with replacing the HG which added lower compression into the mix (milled .008 replaced with .020). Ever since, when temps are cool I have had hazing (still factory 215 injectors) and smoke that really burns your eyes. This has gotter progressively worse. I have always written this off do to the lower compression. This winter cold starting (below -5F) is getting tough. Engine starts but idles very rough and you can not give it any throttle or it stumbles ("floods") and everything around you disappears in white smoke. When truck or ambient temps are 30 or above, starting running are like a champ...other then a little hazing. I do not believe I have any fuel line leaks. Everything has been replaced and again...it runs/starts great when temps above 30.

While I would like to think I am at 17 degrees I am starting to think not. From what I know and read, the above symptoms are classic low timing. I am going to have the timing checked again. Did this a year ago and it was still dead on 17...using the same mark on the dampener used from the beginning. This time we are gong to verify TDC is dead on (thanks Piers for the tips). My questions is when checking timing off the #1 injector line there is difference in the reading depending on where you get the signal. Do you get a more accurate reading when the signal is nearest the injector on the line or nearest to pump? Is checking/setting timing with this method as good as spill port or others? How accruate is it...given a accurate TDC mark.

I have a new overflow valve coming and plan on replacing the injectors very soon.

Thanks for any help....

JJW
ND

 

I have never used a timing light on my 5.9 but I do have a pulse adapter. I would say it would be most accurate the closer it is to the injector. If your TDC mark is accurate I would think it would be very close. I would say not as good as the indicator method since that is how cummins designed it. I would think you are +-1/2 deg. of your setting. It would be interseting to check it both ways to see the difference. do you have degree marks on your dampener?
Your cold start issue sounds like it may be one heater grid not working or a leaking injector. If the truck still runs like it used to when warmed up I would think the timing is ok. It might be worth a check though.
The way you say that the truck puts out a haze even when warmed up that your injectors are leaking. The cold start might be a combination of things.

 

Higher the timing also makes it harder to start in the winter.

 

I use a light to check timing only, to adjust the timing the dial indicator method is easier.
It makes no difference where you connect the sensor to the line.
You will need timing tape made especally for the diameter of the 5.9's dampener. Piers sells it.

 

Timing light??? Please explain, TDC and cam lift with a couple of dial indicators is how I set timing????

 

To time a diesel with a t light you need to have the light connected to a pulse adapter. Some lights designed for a diesel have the adapter built into it. The pulse adapter is a battery powered adapter that you clamp onto the #1 injector line. It senses a minor expansion and contraction of the dia. of the line when the pump sends the pressurized fuel to the injector and the injector opens at pressure and relieves the fuel pressure on the line. To use it with the T light on a diesel you have to find TDC and mark it somewhere on the dampener and a corresponding mark on the case or make a pointer so the two line up. Then you either need to have some degree tape on the dampener that will correspond to deg. of rotation or you need a T light that has deg. advance or retard built into the light. As stated in a post above, on the cummins it is good for checking timing but not so hot for setting. The reason is that it would be a trial and error thing to find the correct timing for setting it. You would have to check the timing,then if not correct, pull the pump gear rotate a smidge put back together and check it again. Then keep doing that till you have the timing you want. But if you want to know if your timing sliped a year later all you do is put the light on and check. You will know in just a few min. I hope I made it clear how this works, if not maybe someone else that is more eloquent can explain it.

 

Got it, thanks, I've never seen one!!

 

Thanks for the feedback. Several years back, we did check the reading difference if the sensor was attached at the pump versus at the injector. Ther reading at the injector was almost 3 degrees less then at the pump.

I am dealing with very stinky (unburned fuel) at startup and in cold weather. I reread threads from back in Nov 02 when the timing was changed along with the headgasket change. The "burn your eyes" smoke appeared at the same time and if anything has gotten alittle worse. I plan on replacing injectors with fresh new ones. But I don't expect that to cure the stink.

From what I read and hear, if the timing on this engine had never been checked, stinky cold smoke is generaly related to low timing. This winter when I have done a very cold start (temps below -5) it really idle rough and could not increase the engine speed without stumble, "flooding" and horendous white smoke......classic low timing symtoms. THe engine always starts and never dies out.

I have always written the smoke off to the slightly lower compression I ended up with (.008 milled - .020 installed). Now I am wondering if the 17 Degrees at the injector is really 17 or more like 13 or 12??? I plan on having the TDC mark (same one that has always been used for timing setting and recheck) verified. If it is dead on then I guess I just put up with a stinky/ smokey truck.

jjw
ND

 

Form what you are saying it does sound like retarded timing. I would suspect that the TDC mark is not correct. If I were you I would get it timed with the dial method and at the same time they can check to see if you TDC marks are right. THen you can check the T light in the future to know if it slips .