HArd start when cold but fine with warm engine

Where would you start on this issue? Cranks strong just takes extra few seconds that did not occur previously.

thanks

Battery preventive maintenance history? The battery is always an excellent place to begin. Refer to section 8F-1

http://diysprinter.co.uk/reference/2006-VA-SM.pdf

More info here: http://diysprinter.co.uk/reference/2006-VA-SM.pdf

Are the glow plugs working???

mendonsy said:

Are the glow plugs working???

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Exposing my (lack of) knowledge - how can/do you test? would a bad plug cause a CEL? and identify which one from a code reader? Think I read on other posts the sprinter can function without all plugs being "good".

white whale said:

Where would you start on this issue? Cranks strong just takes extra few seconds that did not occur previously.

thanks

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Ambient air temperature during start-up?

Bobnoxious said:

Ambient air temperature during start-up?

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cold but not freezing, but will be eventually.

white whale said:

mendonsy said:

Are the glow plugs working???

Click to expand...

Exposing my (lack of) knowledge - how can/do you test?

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I ('cuz i bought one for this express purpose) use a $60 clamp-on DC ammeter to monitor the (roughly) 65 amp current that five happy glow plugs consume. (when dead cold, my start-up current can reach 95 amps, but drops within a couple of seconds to 65)

A plain ohmmeter across a plug's pins would show "infinite" resistance if the plug has died in an "open" (like a dead light bulb) condition.
A happy plug has only about 1/2 (one half) ohm resistance... so measuring one that's drifted up to 1 or 2 ohms is difficult with hobby-priced ohmmeters. Likewise, comparing a "half ohm" to "dead short" is difficult (how to demo that: put your two ohmmeter probes on the engine metal ... that's a dead short, but your reading will probably be bouncing around a bit).

Dr Andy posted a "how to test" involving a 20 amp fuse and a couple of pieces of wire, routing battery power straight to the glow plug.
A happy plug (but, unfortunately, also one that's risen in ohmage) won't pop the fuse.
A shorted plug will (have at least 5 fuses on hand).

would a bad plug cause a CEL?

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Maybe, it depends upon how it's failing. Usually on a T1N the first hint is that the "coil" on the instrument panel stays on after the engine has started.

and identify which one from a code reader?

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If it throws a CEL, it will probably store a which-plug specific code.

Think I read on other posts the sprinter can function without all plugs being "good".

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The Sprinter can "function" with all of the plugs (or the glow plug controller... the older T1N controller has internal fuses that blow (given shorted plugs)) dead. They only assist in start-up and a (very) short time into cold-weather operation.

--dick

Must ask: Are you pausing to allow the “wait to start” lamp (coil) to go out before cranking?
Do you get white smoke on startup when cold? If so you likely have a bad glow plug.
A 2006 _will_ light the CEL and set codes if a glow plug fails. (pre-2004 the ‘coil’ light will come back on after starting)

I could start my 2004 with three working plugs down to about -10’C but there was a lot of cranking and white smoke... and the previous owner cooked the starter trying to start below -20C. Now with 5 new plugs I’m good below -30, though it takes 10-15 seconds for the ‘coil’ lamp to go out before I crank.

-dave

Put your vehicle year etc in your signature svp.

Patrick of M said:

Put your vehicle year etc in your signature svp.

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Does show. I'll add the engine info.

Nautamaran said:

Must ask: Are you pausing to allow the “wait to start” lamp (coil) to go out before cranking?
Do you get white smoke on startup when cold? If so you likely have a bad glow plug.
A 2006 _will_ light the CEL and set codes if a glow plug fails. (pre-2004 the ‘coil’ light will come back on after starting)

I could start my 2004 with three working plugs down to about -10’C but there was a lot of cranking and white smoke... and the previous owner cooked the starter trying to start below -20C. Now with 5 new plugs I’m good below -30, though it takes 10-15 seconds for the ‘coil’ lamp to go out before I crank.

-dave

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No white smoke. I recall now I had one plug changed when I did have white smoke many years ago. It was just a smoke issue I noticed without a hard start, just sounded a bit rough. And yes to the coil wait. This AM was a normal start so not sure now, will monitor. Previous parts order I added 5 bosch plugs for the future. maybe time to replace.

Just to confirm , when the coil light goes out , the plug goes off as well, it does not remain on.
On very cold starts , I'll cycle the coil a few times before turning the key to start - not sure if that does anything to help or hurt.

Again on my engine ignorance, once the engine starts the glow plugs are done, they provide no more function. And if you had 5 dead plugs how could you get mobile if at all?

Minus 30, going nowhere unless plugged in. this year added a battery blanket wrap for extra insurance.

No, the ECM keeps the glow plugs burning for a few minutes after starting to aid combustion and improve emissions during initial warmup. The lamp time is adjusted by the ECM according to coolant temperature, giving the plugs time to reach full temperature (1200’C/2200’F)
I’m also a believer in multiple glow plug cycles in really cold weather, believing that they put heat into the cylinder. Whether my belief is justified I don’t know, but it does no harm beyond draining my battery and it makes me feel better when I do crank and the engine starts on its usual third compression.

-dave

If it starts and runs fine, it's likely not glow plugs. A few cranks of the motor isn't going to suddenly make it warm enough to ignite if it wasn't to start on the first crank
I'm going to say fuel pressure - either low pressure due to air or a pump/regulator issue.
Since it's fine when warm, it's likely air getting in at the filter when sitting overnight.

Re: Hard start when cold but fine with warm engine

Followup - I generally make a habit of giving the battery a trickle charge once fall comes and did so again and figured a three year old battery would still be a safe bet. A few more hard starts from cold so I picked up a load tester - the cheapie 100amp chinese ones. Yes the battery is on the way out, shows as weak. Thank for all that chimed in. Maybe a proactive GP swap won't hurt anyway. Got a little GP education so was a good thread for me!

First time seeing these load testers, I've seen the big wheeled rigs at the garages, never actually knew how these worked -, basically a big fat toaster wire that draws the power... and becomes a hand warmer as a by-product.

The unit will also check the alternator health - was good - and also the starter motor. For that test the instructions say to disable the engine so it won't start, just crank. Says to check vehicle manual.
S-F is better than the manual I don't have. I actually have never looked for the starter motor.
What is easiest, wire , fuse or ?? to pull so I can do a load test on the starter.

And forth bonus will be to give the new battery a fresh tray to sit on with a POR 15 coat to keep the rust at bay. I have some white top coat so this will really put that product to the test, A great rust breading ground.

thanks

You could unplug the LP fuel pump fuse, or for more certainty either the crank position sensor or the cam position sensor can be unplugged. The cam sensor is an easier reach if you don’t mind removing the black plastic injector cover.

Nautamaran said:

You could unplug the LP fuel pump fuse, or for more certainty either the crank position sensor or the cam position sensor can be unplugged. The cam sensor is an easier reach if you don’t mind removing the black plastic injector cover.

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Ok on the fuel pump, was on the short list. But cannot figure what LP stands for?
Never searched for the cam/crank sensors so good time to learn.

LP=Low Pressure.

The “Fuel Pump” fuse is #19 under the steering wheel.

There are seven torx cap screws holding the plastic engine cover on the OM647.
The camshaft sensor is at the rear of the gallery, over the exhaust cam.

The crankshaft sensor is mounted forward of the flywheel, above the starter motor on the side of the engine block.
It can be reached from the ground under the van by reaching forward from behind the left front wheel, or (harder) from above by reaching down under the intake manifold.

Happy hunting,

-dave

fuse is way easier but I'll hunt for the sensors when I do the oil change soon.

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Are there two fuel pumps?, funny to hear about the low pressure distinction. I was told the fuel pump - when I had a change to do - the pressures that it produces was tremendously high, off the charts high in comparison to other vehicles .. ?
This was the large cylinder pump in the tank. Is the LP version something else?

My dear Sprinter brother, if you plan on doing work yourself, read the service manual. Tapping the section number will take you there. YMMV.

http://diysprinter.co.uk/reference/2006-VA-SM.pdf

Enjoy your avatar BTW.