It's just starting to get cold up here and now I'm finding that when I start my truck in the morning (around 18F) it idles like crap with the engine acting like it's going to die. After a few minutes the idle is nice and consistent.

The only mods to the truck is a quazilla 30/60/100 box that I run on the 60hp setting all of the time. I removed the box to make sure that wasn't the problem, but it still does it, though it doesn't seem as bad.

What can cause the truck to do this? Is this an injector issue? Should I remove my injectors and have them inspected?

Also how do you check the compression on a diesel? I was in the throttle pretty hard a month ago trying to get into traffic and hit some gravel which caused me to redline the engine pretty good (hit 3500rpm for a split second). I just want to check for valve damage.

Thanks,
schu

 

has it always done that at low temp?

 

no, when it was brand new it would run be loud when it was cold, but it never had the idle go up and down and sound like it was going to die until this year.

schu

 

change fuel filter first and check for water.

 

Ok, I bought the fuel filter, I'll put it in tomorrow and check back.

 

Could be a sticking FCA valve as well. That's what they sound like when they are going bad.

 

It could be a weak LP also unless it has already been replaced by a Fass or Glacier kit. Check for codes.

 

I'm thinking weak lp since I'm only getting 5lbs and I can easily pull it down to 3lbs on the throttle. I didn't even think to look at the fuel pressure gage when it was running like crap. I'll probably order the glacier kit and get it replaced since it's better that I do it now than in the middle of snowmobiling season.

schu

 

The stock ECM programming changes timing dynamically based on temperature. Basically, what your seeing is normal, however aggravated by the "box" that you are running (which does not change dynamically based on temperature).

What you are experiencing will not hurt anything. It will just cause your engine to take longer to warm up at colder temps. Unplug your box and it will not be as bad, but keep in mind that at AK temps, it will always sound different that it does in summer. That is the nature of the programming, the "box" (if you leave it plugged up), and the cold temperatures.

In a nut shell, unplug the box and know that what you are hearing is normal "cold diesel" clatter, or keep the box during the winter and be gentle on the engine until the engine reaches full operating temp and the timing changes to normal operating parameters. Hope that helps.

On edit: You should be changing to a good synthetic oil about this time of the year. That will help tremendously with the engine clatter.

 

AK Ram,

It's not the normal cold diesel clatter, the idle is going up and down a few hundred rpm and a few times it stalled enough to almost die. More like fuel problems not cold engine problems. Besides it was only 18F which isn't that cold, it's certainly been started in much colder.

As far as oil I have a lifetime oil change though the dealer so I have been using whatever they put in it. Perhaps I should ask if I can pay the difference and have them use synthetic oil. Do you recommend synthetic all of the time or only in the winter?

BTW, really cool videos, I should come out and watch sometime.

schu

 

Yup.......double check your fuel pressure, and the get a rail pressure guage so you can watch that when it acts up. If the fuel pressure is o.k. when it is acting up - watch rail pressure. If the rail pressure is fluctuating, I would say FCA is sticking.

 

Check your fuel pressure, but my dads 04 did the same thing, and it still does it. His FP is fine, but he's thinking it might be an injector sticking.
Scott

 

Ok, I did a little more digging and got it to throw a P0193 Fuel Rail Pressure Sensor Circuit High Input. This is causing me to suspect my FCA valve. Is it possible the box could have caused the FCA valve failure? Sounds like I may need to remove the box then take it to the dealer.

schu

 

There is a TSB for the 03 trucks on idle speed fluctuation. The repair process has them check all fuel system components one at a time. If no obvious problems are found, it instructs them to replace the fuel control actuator.

 

Do you have the TSB number? Thanks for the info.

schu