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ADMIN/MAFIA
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Discussion Starter #1
Alright lets see here.

This is my neighbors truck.

2001 F350 CCLB DRW XLT 7.3L/4R100 4.10 78K
He has some oil leaks fixed when he got it. I do know that one was a Cam sensor leaking.

It started smoking white on start up so he took it in to a diesel shop, Same shop has done work for me and did great work.

They Replaced the #8 Injector. ( No smoke for a couple days)
It started smoking again. went back to same shop.
Before it went back we took a snap-on scan tool and did buzz testing on the sticks. ( Passed they all sounded good) then Cylinder Contribution Test. It says #8 out of threshold ( however it words it) Would it think because it was a new injector that its bad or could 1-7 be bad and it show that one cause it is different/newer?

Shop tests and finds no issue so they try a new Glow Plug in #8. still smokes so they put another new injector in it. ( they say no smoke)

He gets it home and a couple days later smoke it back.

Now ( maybe past week)

When the truck is cold hasn't ran for a day or so it starts and runs find for like 15-30 sec and shakes for 10-20 secs then runs perfect. ( still smokes a on start up.)

Now the list of what people say could be wrong with it.
injector O-ring ( I believe this could be the case due to the truck sitting alot before)

Injectors ( one or all)
Glow plugs ( one or all :shrugs)
ECM on its way out
Fuel blow cracked
HPOP

Now and I missing anything. and what can I check/ test to prove anything. After the truck runs for about 1-3 mins it is totally fine. runs fine, doesn't fall on its face if you hammer it NOTHING> So can someone educate the Cummins guy who doesn't was it admit defeat.
 

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Senior Member
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862 Posts
Ignore the cylinder contribution test. Since he recently replaced the CPS, then he's running an redesigned CPS rather than the original. The new CPS's often throw failures on cylinder #8, and sometimes #3. Basically the shop needs to quit swapping the #8 injector. It's just wasting money and time chasing a ghost problem. I'm willing to bet there was absolutely nothing wrong with the original #8 injector.

Now how much smoke are we talking here? You say after a minute or so the truck is fine. Give me an idea of how much it smokes when the engine is cold. Mine will sometimes puff out a wee bit of white smoke after it's sat for a day or so. It's always done this ever since I first bought it.

Lastly, is the truck using oil?
 

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Junior Member
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what is a cps? I don't think they replaced anything but the injector.
 

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ADMIN/MAFIA
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Discussion Starter #6
what is a cps? I don't think they replaced anything but the injector.
Sorry Ryan I thought at one point a glow plug was brought up.

So a cam position sensor (CPS) :thinking... may be worth a shot.
 

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ADMIN/MAFIA
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Discussion Starter #7
Ignore the cylinder contribution test. Since he recently replaced the CPS, then he's running an redesigned CPS rather than the original. The new CPS's often throw failures on cylinder #8, and sometimes #3. Basically the shop needs to quit swapping the #8 injector. It's just wasting money and time chasing a ghost problem. I'm willing to bet there was absolutely nothing wrong with the original #8 injector.

Now how much smoke are we talking here? You say after a minute or so the truck is fine. Give me an idea of how much it smokes when the engine is cold. Mine will sometimes puff out a wee bit of white smoke after it's sat for a day or so. It's always done this ever since I first bought it.

Lastly, is the truck using oil?
I believe that the CPS only had a gasket replaced. Are you saying that the CPS went bad or what, as far as we know its the original OEM CPS.
 

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i agree with pocket, sounds like it could be a cam sensor. let us know what you find, the sensor should be les than $30
 

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Senior Member
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I believe that the CPS only had a gasket replaced. Are you saying that the CPS went bad or what, as far as we know its the original OEM CPS.
Original OEM CPS's are black in color. If it isn't black now, it isn't original.

The recall for the CPS has been active for a few years now. Since your friend bought the truck used, the previous owner could have had the recall done.

The recall CPS (updated CPS) is grey in color. The problem with the new style CPS is false CCT failures, typically on #8 cylinder, and often on #3 as well.

Now these CPS's do not cause smoke. That's why in my previous post I asked how much the truck is smoking, and if it's using oil. Basically you can ignore the CCT failure on #8, and have your friend quit wasting time and money swapping out injectors.
 

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Discussion Starter #11
It has a decent ammout of whitish blue smoke on a cold start. And has more recently started the rough idle as stated earlier, I will have him check the oil tonight.
 

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TDG Mafia - Booze Runner
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Does the smoke clear up and rough idle go way after it warms up? Could be worn rings.
I know mine smoked white at startup for the last 60 some odds thousand miles of its life, bigger injectors kinda made it worse.. Compression was a little out of speck in #1 and #3 during a cold start. Always thought it would just give up one day but never did...
 

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Discussion Starter #13
Does the smoke clear up and rough idle go way after it warms up? Could be worn rings.
I know mine smoked white at startup for the last 60 some odds thousand miles of its life, bigger injectors kinda made it worse.. Compression was a little out of speck in #1 and #3 during a cold start. Always thought it would just give up one day but never did...
At 78K, I sure hope not.....But yeah it only does it when its sat for 8 or more hours, and yes it only smokes for like 20 sec and the rough idle may last about that long... only does it cold.. you could start it and let it run for 10 min and wait 10 min and start it and it will not do it.
 

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Discussion Starter #14
Is there any way to test the Injector Pressure Regulator? Also wondering, could it be a valve over gasket since it is the injector harness as well? just wondering why it would be better after it comes back from the shop then a few days later its doing the same thing, if the harness was going bad it may be making a good connection for the few days after it has been messed with?
Just Fishing for more Ideas.

Thanks Again!
 

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Super Moderator
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The symptoms are consistant with a few different and possibally overlapping problems.

White/blue smoke is from a cold cylinder, i.e.: incomplete combustion.

Regardless of mileage, the engine is still almost 10 years old and a LOT of things can happen in that amount of time. It is unlikely, but possible, that the injector poppets are just at the point in wear where an astute owner would notice a stumble or starting concern when cold. One way to determine this is to change the oil (15W-40) and see if that helps. Clean oil is a big factor in driveability/starting concerns with the HEUI system. If that makes no change, try a lighter oil like 10W-30, if that takes the problem away after a day or so, well you have done as much as possible to confirm at least one injector has enough wear to affect operation when cold. I don't *think* this will be the case however, read below.

The timing of the smoke and rough running is also consistant with: 1) A bad GP or two - although highly unusual, and 2) the GP relay cycling after the vehicle is started placing a large electrical load on the alternator and consequently engine. If the IPR valve cannot respond accurately or the ICP sensor is not reading accurately after a cold start, a rough running condition can occur. This will typically clear up as the oil warms.

What to do? My suggestions in order of simplicity and cost aare:
1) Load test all GPs (test light to B+, then touch the male GP terminals on the UVC w/o removing the VC, just unplug the connector) If ALL GPs light the light brightly, they and the wiring are OK.
2) Use same test lamp and monitor the GPR, if the roughness happens while the GPR is post-start cycling make sure the battery cables and batteries are in good condition.
3) Check ICP at KOEO, if over 15 PSI replace the ICP sensor.
4) Monitor ICP and ICPD during starting and while the proble occurs, if they are more than 50 PSI different and the ICP sensor is good ( < 15 psi @ KOEO) replace the IPR.
5) Change the oil (if not recently done, like 1500 miles or less) to a GOOD wuality 15W-40 and see if that helps.
6) Change the new 15W-40 to 10W-30 and see if that helps, if it does and your neighbor likes the performance now, consider 8 new injectors.
 

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ADMIN/MAFIA
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Discussion Starter #16
Thanks John, are there any special tools needed to do any of this testing?
 

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Super Moderator
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Scan tool, that's about it.
 

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Discussion Starter #18

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Junior Member
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plug the truck in for a few hours and see how it start's


did this truck idle a lot, I wounder how many hours are on the engine, A few years ago my friend but a 00' F450 service truck that had 102,XXX miles on it and it would run really rough and skip until it warmed up, also it would not start unless plugged in if the temp was less then 50*, new glow plugs and GPR, same issue.

This truck had a PTO air compressor and Jump starter (for big equipment) turns out this truck idled more than anything.

I pulled the injector solenoids and measured the armature plate to injector body clearance, I couldn't get a 0.0015" feeler gauge between the armature and the injector body (worn poppet valve), a new injector is 0.004-0.005" clearance.

It took my 01' F350 500k miles to get the injectors poppet valves this worn. Extended oil changes, dirty oil (K&N air filter), ect can cause premature poppet wear.

I shimmed up the armature plates with .002" + .001" (to get 0.003") 6.9/7.3 IDI injector shims, and it starts like a new 7.3. And has 250k now with no issues.

If you call me I can tell you how to check it, and how to instal the shims with out pulling the injectors.
 
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