238/80's smoking on cold start

So I contacted a couple of injector builders, both of them tell me that it is not a tuning issue. It is more or less just the way it is with 238/80s or 250/80's.

Really considering selling these and going back to stockish. I dislike any smoke.

Smoke on startup cant be just a "normal" thing with a larger injector can it? I would like to think smoke on startup would be caused by an injector builder cutting corners during the rebuild process.

A cold engine can’t create enough heat to burn all the fuel that is needed with bigger nozzles. Once engine temps are up, then the smoke should go away

Magnum PD said:

A cold engine can’t create enough heat to burn all the fuel that is needed with bigger nozzles. Once engine temps are up, then the smoke should go away

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It does. Smokes 0 once eot is around 120-140 as verified by my aftermarket gauge.

Lt.Dan said:

Smoke on startup cant be just a "normal" thing with a larger injector can it? I would like to think smoke on startup would be caused by an injector builder cutting corners during the rebuild process.

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That is exactly what my thought it. Some tuners have said they can "fix" most of it I've got a cold start tune enroute, that may minimize it. . I've talked to the company that built them, and one more and they alluded to it being normal due to not being able to atomize the fuel, but for it to go on for minutes I am not sure I buy.

But at this point, I am considering going to some brand new Alliant Power stockers, or something like a 160 and calling it good.

Not a fan of smoke, and it doesn't do anything good for the diesel hobby.

First of all you went from split shot injectors to single shots. Single shots may smoke a little more on a cold start. Yes many injector builders cut corners they use shims and some likely use low end parts to increase profits. Bran new injectors vs remans no matter what size new is a better choice. Not sure how much smoke your seeing. Some cold haze is normal. My 200% nozzles barely haze down to freezing temps. I am running B codes with higher VOP than a A code/hybrid. Tuning can help. Changing nozzle size effects SOI and atomization at lower ICP like at idle. Some adjustment to PW, ICP, SOI and the multipliers can help cold haze. Tuning is an art in dome ways. Changing one parameter can effect something else. For example increasing ICP will advance timing. Installing a larger nozzle without changing anything will advance timing, higher VOP will retard timing etc etc.

This is my 7.3 idling on a cold engine 200% nozzles at 400 rpm.
https://youtu.be/e_xCe2caUY4

Motor has maybe 10 thousand miles on it after a rebuild but probably less than that. Sometimes it’s completely clear like the pic sometimes there’s a very slight haze. My last set which was 175/80 would heavy blue smoke until 140-150 eot. Also on a tired engine that I have since replaced. It is idling in this pic.

250/200s.

glovemeister said:

That is exactly what my thought it. Some tuners have said they can "fix" most of it I've got a cold start tune enroute, that may minimize it. . I've talked to the company that built them, and one more and they alluded to it being normal due to not being able to atomize the fuel, but for it to go on for minutes I am not sure I buy.



But at this point, I am considering going to some brand new Alliant Power stockers, or something like a 160 and calling it good.



Not a fan of smoke, and it doesn't do anything good for the diesel hobby.

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Additional timing at idle from your tuner will help prevent the cold startup smoke and haze.
Of course go through and check over your glow plug system for correct operation.. also
Are you running any oil and or fuel additives? What brand oil.


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This all kind of puts my mind as ease for the 238/80s I want to do. Thanks guys

my 250/100's haze/strong eye burning smell at startup no matter what the ambient temp is. Worse when it's colder. when warmer ambient temps it will clear after driving it a bit. during cold months it gets better but the haze never goes away.

Others have run similar injectors without issue. every truck will react slightly different. I just have the rare occasion bad luck with everything.

I also lost 2-3mpg from sock injectors to these 250/100s. I have contemplated for yrs about switching injectors but have never talked myself into it; the added power has been too much fun. It would be hard to go backwards. Luckily i don't put many miles on this truck in a yr.

best of luck in what you decide to do