Can anyone help with my starting issue?
Discussion
Vehicle is a 2011 W639 Merc Vito van. 2.2. diesel with 208k miles. New battery fitted about 6 months ago.
Had it 2 years and for the past 12 months it has been slow to start.
Runs fine when it gets going, only it needs a good 3 seconds of cranking and squeeze of the gas pedal before it starts.
If I stop and then re-start, it fires almost immediately though.
When I bought the van, it started fine but I stupidly decided to add some random ebay injector cleaner to the tank one day. I had a week of intermittent boost issues but after that tank full was gone, it ran fine, but I had the starting issue.
Guessing the issue might be linked to the injector cleaner but surely it wouldn't run fine?
Any help appreciated, I've done a fair few basic DIY tasks like servicing, brakes, basic suspension work etc and plan to pull the injector cover to check for leaking injectors / black death as I gather that might account for poor starting.
Had it 2 years and for the past 12 months it has been slow to start.
Runs fine when it gets going, only it needs a good 3 seconds of cranking and squeeze of the gas pedal before it starts.
If I stop and then re-start, it fires almost immediately though.
When I bought the van, it started fine but I stupidly decided to add some random ebay injector cleaner to the tank one day. I had a week of intermittent boost issues but after that tank full was gone, it ran fine, but I had the starting issue.
Guessing the issue might be linked to the injector cleaner but surely it wouldn't run fine?
Any help appreciated, I've done a fair few basic DIY tasks like servicing, brakes, basic suspension work etc and plan to pull the injector cover to check for leaking injectors / black death as I gather that might account for poor starting.
Completely different vehicle...but my '06 Sprinter would be slow to start when the weather was cool because the glow plugs were not at their best. Most of the glow plugs were no longer working. Once I changed out the glow plugs for new ones it started up like the day I bought it 16 years ago.
Never touched the throttle at any time.
Arthur
Never touched the throttle at any time.
Arthur
We'll assume you've done the usual good servicing, including new fuel and air filters etc.
To check for fuel draining back to the tank, is there a primer pump on or close to the fuel filter assembly? if so before you go to cold start next time give the plunger a press or two, it should be instantly hard to press, if it takes multiple pushes/compresses before it goes hard that means the fuel filter wasn't primed full...once the primer goes stiff to press the fuel filter is full, if it then starts instantly after manual priming you appear to have a fuel draining back issue, i've had this with a cheap make fuel filter once with a deformed top seal stamping, no accessory shop cheap filters after that experience.
To check glow plugs, ideally you need to remove them and see them working for yourself by wiring them individually direct from a battery.
However before now i've had success in identifying fuff glow plugs by isolating.
Remove the existing connection to each plug and via a live wire running through an ammeter temporarily hot wire each plug in turn and see how much current each consumes, the last time i did this a good plug took around 15amps but plugs on more modern vehicles may be more, whatever the value is if you find one or more with wildly different power consumptions you have glow plug issues.
To check for fuel draining back to the tank, is there a primer pump on or close to the fuel filter assembly? if so before you go to cold start next time give the plunger a press or two, it should be instantly hard to press, if it takes multiple pushes/compresses before it goes hard that means the fuel filter wasn't primed full...once the primer goes stiff to press the fuel filter is full, if it then starts instantly after manual priming you appear to have a fuel draining back issue, i've had this with a cheap make fuel filter once with a deformed top seal stamping, no accessory shop cheap filters after that experience.
To check glow plugs, ideally you need to remove them and see them working for yourself by wiring them individually direct from a battery.
However before now i've had success in identifying fuff glow plugs by isolating.
Remove the existing connection to each plug and via a live wire running through an ammeter temporarily hot wire each plug in turn and see how much current each consumes, the last time i did this a good plug took around 15amps but plugs on more modern vehicles may be more, whatever the value is if you find one or more with wildly different power consumptions you have glow plug issues.
Don't bother cycling the key multiple times before trying to start, just turn it to the one position before engaging the starter & leave it for a few seconds.
If that helps, your fuel is draining back to tank.
As others have said 3 seconds isn't a lot, I wouldn't be chasing a non-existent issue at 3 seconds.
If that helps, your fuel is draining back to tank.
As others have said 3 seconds isn't a lot, I wouldn't be chasing a non-existent issue at 3 seconds.
3 seconds is a long time for a modern engine....but if it always starts, hardly a big deal. And 200k isn't big miles really.
Have you actually tested anything at all ?
Glow plugs would be a first start...although most ecu's will report a glow plug problem
crank/cam triggers would be a sensible step, as issues there can cause a slow start. Assuming of course it is actually winding over at a sensible speed for a normal quick start. Scope them both and compare against a known good.
You could check for drain back, although if it was doing that and there was no lift pump, it would probably take longer than 3 seconds to re-prime.
If it has a lift pump, cycling the key a few times before start might enable it to start quicker if it is a drain back issue.
Have you actually tested anything at all ?
Glow plugs would be a first start...although most ecu's will report a glow plug problem
crank/cam triggers would be a sensible step, as issues there can cause a slow start. Assuming of course it is actually winding over at a sensible speed for a normal quick start. Scope them both and compare against a known good.
You could check for drain back, although if it was doing that and there was no lift pump, it would probably take longer than 3 seconds to re-prime.
If it has a lift pump, cycling the key a few times before start might enable it to start quicker if it is a drain back issue.
Thanks for the suggestions everyone. Got my FIL coming down on the weekend and he's far more mechanically experienced than me so we'll do some testing.
I think the fuel draining point might be on the right track as there have been some occasions where I've stopped and re-started shortly after and it's fired up immediately.
I think the fuel draining point might be on the right track as there have been some occasions where I've stopped and re-started shortly after and it's fired up immediately.
Smint said:
We'll assume you've done the usual good servicing, including new fuel and air filters etc.
To check for fuel draining back to the tank, is there a primer pump on or close to the fuel filter assembly? if so before you go to cold start next time give the plunger a press or two, it should be instantly hard to press, if it takes multiple pushes/compresses before it goes hard that means the fuel filter wasn't primed full...once the primer goes stiff to press the fuel filter is full, if it then starts instantly after manual priming you appear to have a fuel draining back issue, i've had this with a cheap make fuel filter once with a deformed top seal stamping, no accessory shop cheap filters after that experience.
To check glow plugs, ideally you need to remove them and see them working for yourself by wiring them individually direct from a battery.
However before now i've had success in identifying fuff glow plugs by isolating.
Remove the existing connection to each plug and via a live wire running through an ammeter temporarily hot wire each plug in turn and see how much current each consumes, the last time i did this a good plug took around 15amps but plugs on more modern vehicles may be more, whatever the value is if you find one or more with wildly different power consumptions you have glow plug issues.
To check for fuel draining back to the tank, is there a primer pump on or close to the fuel filter assembly? if so before you go to cold start next time give the plunger a press or two, it should be instantly hard to press, if it takes multiple pushes/compresses before it goes hard that means the fuel filter wasn't primed full...once the primer goes stiff to press the fuel filter is full, if it then starts instantly after manual priming you appear to have a fuel draining back issue, i've had this with a cheap make fuel filter once with a deformed top seal stamping, no accessory shop cheap filters after that experience.
To check glow plugs, ideally you need to remove them and see them working for yourself by wiring them individually direct from a battery.
However before now i've had success in identifying fuff glow plugs by isolating.
Remove the existing connection to each plug and via a live wire running through an ammeter temporarily hot wire each plug in turn and see how much current each consumes, the last time i did this a good plug took around 15amps but plugs on more modern vehicles may be more, whatever the value is if you find one or more with wildly different power consumptions you have glow plug issues.
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