7.3 Smoke on cold start

gtbensley

Explorer
Replaced FF, icp sensor. Monitored some numbers, high pressure oil under WOT got up to 4125psi which seemed very good. Pump duty cycle got up to 68% under WOT but ran 12-14% at idle and about 20-23% just running down the road. All these seem pretty healthy to me.

Thinking its a tired injector when cold. Will just let it go I guess.

Edit:3125PSI...not 4125PSI. That was also a single spike, not a constant hold of pressure. Under load WOT it was running 2800-3000PSI. Same with the duty cycle of the pump, spike was 68% but it was running a constant 20-23% under load down the road with holding under 50% under hard acceleration.
 
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gtbensley

Explorer
I added some archoil Friday as well. Have been gone all weekend though so haven't got to drive it much and see if it makes a difference.
 

gtbensley

Explorer
We shall see, everything I read was positive about it. Even if it's not the problem, it's probably better for the motor anyways.
 

surlydiesel

Adventurer
Both of my 7.3's smoked some when cold. I assumed I had a few dead glowplugs...interesting thread but I wouldn't worry too much about it.

-jorge
 

offthepath

Adventurer
I have a 2001 that I am having a similar problem with, excessive smoke when cold. If you let it idle it will smoke (blue) a very long time, but if driven a 1/4 mile or less it clears up. Seems to do it under about 40 degrees. I can understand smoke from an older diesel when you get temps into the teens and bellow, but above freezing is dumb. It really irritates me and it kind of embarrassing. I cant be 100% sure but it seemed like mine started when I switched to single shot stage 1.5 injectors. Shortly after the injector swap the engine was rebuilt, including all new glow plug system and the big *** relay. I run DP tunes and they said they can add a tune to the chip to help the smoke. According them some 7.3 just smoke at cold start......I have not sent it in but probably will.

I have read a ton on this issue and never heard about the CPS. I may have to play with that and see if it changes. Thanks.
 

gtbensley

Explorer
Offthepath, I have also read lots on this issue and would imagine its your larger injectors causing the haze until warm. Seems like a somewhat common issue.

Surlydiesel, I would say some lightish smoke is normal, but mine does it when first started at 50-60 degrees and its not just a small puff but a decent amount. As soon as it goes into drive and I have 50 feet the haze is gone and the exhaust is nice and clear. The glow plugs, relay, and all the wiring are new so I dont suspect thats the issue.

Mine is also bone stock, which shouldnt have an issue with smoke due to fuel.

Thinking its worn injectors, CPS, or IDM over fueling.....Curious as hell to figure it out but dont really care at the same time if that makes any sense.

Its coming back into the shop tonight to have the front wheel bearing replaced, new brakes, new front sway bar bushings, and hopefully I will swap in my old working CPS to see if that makes a difference.
 

Buliwyf

Viking with a Hammer
Oh yeah, cold aftermarket injectors are much smokier than stock. No doubt about that one.
 

surlydiesel

Adventurer
50-60 degrees is really warm to have significant smoke. I was referring to 40 degrees or under. I mean when it was 8 degrees and windy in the mountain lot after work, I always had my fingers crossed it would start at all...

I've never heard of the CPS causing issues at start, that's why I'm finding this thread so interesting. Is it possible the EBPV is getting hung up??? The tube needs to be cleaned out regularly with a wire to keep it working properly. I wired mine to a switch.

Keep us posted if you find a cure.

Cheers,
Jorge
 

gtbensley

Explorer
I appreciate the input from all ^^ yes its a bit warm.

Starts like a champ even at 10-15 degrees not plugged in and smokes then too, but that I would say is normal.

I havent heard of the CPS causing issues like this either besides the gentleman a few pages back who stated it fixed his. Worth a try as it only takes a few minutes and I have a spare one.

I thought it might be the EBPV but that should cause smoke...might make it go away faster though. I cleaned the tube and installed a new sensor and it definitely reads correctly.

I should probably check my engine oil sensor and make sure that is reading close to ambient temp as well as coolant. Those both must feed info in to the PCM for starts and could change the amount of fuel being injected on start up.....or possibly I just have worn injectors that are leaking down some. As long as I am not washing the cylinder I dont really care.
 

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