Need some help diagnosing this Hard Start problem

OT-OF-Here

OT-OF-Here

Owner of the Black Beach
Joined
May 18, 2007
Messages
950
Here's what is happening.

It hard starts for close to a minute b-4 it fires. After maybe 20 sec it starts with white smoke. I keep cranking and it eventually starts and the white smoke clears and it runs perfect.

If I plug it in overnight it starts as fast as you hit the key and NO white smoke at startup or while it is running.

Since there is NO white smoke when it runs and NONE when plugged in then it is unlike any injector problem I ever had previous, which is why I don't think this is an injector problem. I see the white smoke as simply an excess of fuel in the cylinder when it does fire and that is after a heck of a lot of cranking.

FYI, the MAP sensor was just changed but the same issues continue.

Thoughts???
 
we have a customer that white smoke's on start up. Alot sent his injectors for testing in they checked out good. So customer pulled head pistons looked good to him put back togather in truck still white smokes on start up not as bad though. Done put different prv on it also. Customer is doing his own work didnt bring to us except scan tool hook up. Truck isnt hard to start eighter.

What would be your guys thoughts, i've talked to a few other's and they say replace temp sensor. This was from a tech at cummins who has worked there for 10 years said he's seen it twice.
 
OT-OF-Here said:
Here's what is happening.

It hard starts for close to a minute b-4 it fires. After maybe 20 sec it starts with white smoke. I keep cranking and it eventually starts and the white smoke clears and it runs perfect.

If I plug it in overnight it starts as fast as you hit the key and NO white smoke at startup or while it is running.

Since there is NO white smoke when it runs and NONE when plugged in then it is unlike any injector problem I ever had previous, which is why I don't think this is an injector problem. I see the white smoke as simply an excess of fuel in the cylinder when it does fire and that is after a heck of a lot of cranking.

FYI, the MAP sensor was just changed but the same issues continue.

Thoughts???
Click to expand...


Good. I'm glad you posted this up Pat. As I said when we spoke I remember this issue with another CR, but I can't remember what we did to fix it.
The plugging in thing is what gets me.
 
Posted

Snedge said:
Good. I'm glad you posted this up Pat. As I said when we spoke I remember this issue with another CR, but I can't remember what we did to fix it.
The plugging in thing is what gets me.
Click to expand...

I figured this can't be a one truck problem and this is the place in the past that has given me the clues I need.

Yeh on the plug in. This thing will start so fast it makes your head spin like your looking for a timing mark and Vroooom!

I forgot to mention that once I start it in the morning, and drive a few miles, I can leave it sit for 5 to 6 hours before it's started again and it fires right now,.. NO white smoke or prolonged cranking. That's pretty much a cold engine at that point.
 
Last edited:
Have you tried trying to start it just after plugging it in ?
 
Starting procedure

Snedge said:
Have you tried trying to start it just after plugging it in ?
Click to expand...

Yes. That doesn't work. It takes around 1 1/2 to 2 hours for the plug in to impact the startup. Obviously that's when it's cold as in me forgetting to plug in the night before.
 
x2. If the rail pressure gauge is showing that the truck has adequate rail pressure to start the entire time it is cranking, then a CP3, or any fuel related component for that matter doesn't seem to be the problem....

Is it possible the rail pressure gauge is not reading correctly? Could you use a scan tool to verify that the RP gauge is showing what the ECM is seeing?

Do you know the history of the truck? Mileage?

When the truck does eventually start and run, how does it run?
 
Snedge said:
Chris your post did not go unnoticed, but I'm struggling to find the logic.
Click to expand...

Believe me I beat my head trying to figure mine out too and the elimination process lead to a bad CP3 and the CP3 I removed was tried on another engine out of curiosity and it was a hard start case again. Maybe we could send him that one of mine to try out? Just want to help..
 
Chris, was the rail pressure acting up in your case when the truck was trying to start? Or was everything normal?
 
CSnyder said:
Believe me I beat my head trying to figure mine out too and the elimination process lead to a bad CP3 and the CP3 I removed was tried on another engine out of curiosity and it was a hard start case again. Maybe we could send him that one of mine to try out? Just want to help..
Click to expand...


Pat has two pumps.

Was yours the same? Plugging it in caused it to start like a champ?
 
Hard Start

When it's been plugged in it starts and runs great,...excellent! Yes, dual cp3s on it. Start and idle at 7k rail pressure. Varified on a scan tool today. 67k miles only on this truck. I've had it since day 1. This is as close as you'll get to a new 04.5. Complete rebuild at 52k w/ balance job. As stated previous,..I can start it up after being plugged in and runs great. Drive around awhile and get back in it 6 or 7 hours later (should be cold right?) and it starts immediately. But you leave this sucker over night without pluggin it in and it almost won't start. It takes almost a minute of cranking to get it to fire.

Also when it is NOT plugged in over night and you turn on the key to cycle the grid heater light and it goes off quickly but results in the hard start discussed above. Could the grid heater be faulty and cause this? You would think with an ambient temp of maybe 85 deg in the morning and later in the day the temps soar to 100 deg plus and it will still have the hard start problem.

Commmmmmon gurus???
 
This is just a thought, but do the injectors have the right washers? Like if they aren't sitting in deep enough? I've seen this before, an wen the engine is cold it won't start but any little heat an it fires an runs fine!!
 
Morning dew getting in one if the sensors? Leave it out overnight but park it so the morning sun can hit it.
 
It white smokes during cranking suggesting its getting fuel? Like a healthy amount? A compression issue right across the board fits. Didnt get smokin hot did it?
 
You must log in or register to reply here.
Top