Long crank before starting (6-8 seconds)

jzf0fk

Member
Hello

I have a 10' Passenger 144 WB model. In the last few months, my van doesn't start on the first crank. It takes about 6-8 seconds of cranking before the diesel kicks in. Never had a situation where the van didn't start. I had my local mechanic check this out and the fuel & electrical appear to be fine. He even replace the fuel filter and no difference. The voltage runs at 13.7...

I read a post that indicated that there might be air getting into the fuel line. I forgot the link and but have it on my other device.

In terms of driving, the highway speed is fine. No problem in terms passing. Fuel consumption appears to be consistent. I do notice that on stop and go traffic, when I floor (not all the way but half way) the pedal, the pickup isn't instant like in the past. Could be the AC I am running (front and rear).

My mechanic is a bit puzzled by this situation. I might have to bring this to the dealer but wanted to see if anyone else had this issue and what fix you performed.

Any help is much appreciated...

Richard
 

sprintguy

16+ yrs Master Commercial technician
Have your mechanic do a leak off test of the injectors. He may just find 1 leaking back more than the others. The test should be performed while the engine is running preferably around 1500 RPM.

Good luck
Carl
 

bcislander

'07 Mercedes-badged Dodge
Hello

I have a 10' Passenger 144 WB model. In the last few months, my van doesn't start on the first crank. It takes about 6-8 seconds of cranking before the diesel kicks in. Never had a situation where the van didn't start. I had my local mechanic check this out and the fuel & electrical appear to be fine. He even replace the fuel filter and no difference. The voltage runs at 13.7...
snip....
That voltage is low, if you measured it with the engine running. It should be 14.2V to 14.3V in order to fully charge the starting battery. Slightly slower cranking due to a 'weak' battery could be the cause of your problem.

The most likely causes: the 'infamous' Y-Cable and/or the ground strap connection points between the engine block and frame.
 

irvingj

2015 RT SS Agile (3.0L)
I'd also go with voltage that's slightly low, just based on my experience (2015 NCV3, OM642 V-6).

Ours had always started very --surprisingly-- quickly for a diesel, even after sitting for a week or two, during its first year. (Much quicker than my 2005 Jetta TDI, for example!)

After the first year and our first long trip, however, I noticed that it took noticeably longer cranking before it'd fire up, if it had been sitting. Not bad, and it never failed to start, but that initial start-up after sitting for a while sure seemed to take longer. Once the initial start was completed it would be fine ("normal" quick start), until after the next time it had sat unused in our driveway.

Duration of sitting seemed related, so I began to track battery "at rest" voltage. I found that after only one week that voltage --though still "fine"-- would drop a few hundredths. After two weeks of sitting idle, it would begin to drop below 12.6 volts. Not huge, but measurable.

Keep in mind it never failed to start; hell, the first year we stored it over the winter I didn't disconnect the battery (plug below accelerator pedal), and it still started, even after 3 months! But it did seem to take a bit longer, probably 5-6 seconds of cranking -- after having not been started for a time.

Leaking injectors? Some other mechanical issue? Don't know. I finally did invest in one of those smart battery maintainer things, so I could keep it plugged in while it was sitting in the driveway. It's one of those with the nifty de-sulfator feature: bulk charge, changing to trickle charge, and a high-voltage shot once a second, it seems. In any case, if I disconnect the thing and check the voltage, it seems it maintains it (before a total "rest" period) closer to 13 volts.

Now, even after sitting for two weeks+, it fires up after only a second or so of cranking, just like it used to. Of course, this is waiting for the glow plug light to go out, about 2-3 seconds, maybe.

My conclusion: something in there doesn't care for low voltage, even slightly low. Don't know what it is (fuel pump(s)? Glow plugs? CPU? Cranking speed? All of the above?...??) but it now starts up very quickly, even after sitting idle for a time.

Works for me.
 

Eric Experience

Well-known member
Richard
The most likely reason is air in the high pressure pump. How this happens is simple enough, the highest point on the fuel system is the inlet to the high pressure pump so any air in the system will collect there and when you crank it goes strait into the pump. If you look very closely at the fuel line where it goes into the pump you may see the air. If I have this problem I replace the O ring on the fuel line, that often fixes it. Eric.
 

220629

Well-known member
First. Given your in tank electric fuel pump supplying fuel under pressure air leaks are commonly not an issue for hard starting. If careful inspection reveals no evidence of fuel leaking, you can mostly check that one off any list for NAS aka NAFTA 2004 MY and up.

As mentioned, the Wye cable has some history of problems. Some info is here.

https://sprinter-source.com/forum/showthread.php?p=86851#post86851

If no other causes are identified, EGR issues can affect starting.

vic
 
Last edited:

Eric Experience

Well-known member
Vic
I acknowledge you expertise on sprinters, but I have to suggest that if you do have an air leak into the fuel line when the pump is off then the air is still there when the pump fires up and pushes it into the pump. Eric.
 

220629

Well-known member
Vic
I acknowledge you expertise on sprinters, but I have to suggest that if you do have an air leak into the fuel line when the pump is off then the air is still there when the pump fires up and pushes it into the pump. Eric.
Thanks.

:hmmm:

A possibility. That said, it would seem to me that under most circumstances if there is enough leak to allow air in, then there would be a fuel leak while under pressure.

I suppose that it is possible for a leak to respond differently under the slight vacuum of system off as opposed to under system under pressure, or a small fuel leak may go unnoticed.

I modified the statement.

:cheers: vic
 
Last edited:

jzf0fk

Member
I brought the van into the dealer to have them take a look. It turned out to be a faulty cam shaft senor. Their diagnostic machine returned a code of 108900.

Van is starting fine now. Many thanks for those who commented.

Hopefully no one will have to go through this but here are the notes and history for your reference.
 

Top Bottom