Vito van won't start when warm

[Vixser]

Hi guys, I recently decided to sell my van, and I think it might have heard me because it's since started developing a couple of small problems that I really would like to have fixed before she goes!

I have an S reg diesel Mercedes Vito van. It starts perfectly fine from cold, glow plugs warm up fine and the light goes out, and it starts first time. however when it's been running a while and I stop for a short while, for example to get diesel, it wont start properly.

When attempting to start at the fuel station, the glow plug light wont go out, even after 5 mins. If I attempt to start it anyway the starter motor turns just fine and it sounds like it's going to start, however it just wont catch. If I put the accelerator flat to the floor and attempt to start it, it turns over and runs, but it rumbles at just above stall point and letting my foot off the accelerator makes it cut out.

I eventually got it started by getting my sister to start it with the accelerator flat to the floor so it rumbled, and manually opening the throttle from under the bonnet. After revving it a few seconds, I let it go and the van ran as normal.

My local mechanic said 'I'll need to see it do it before I can try to fix it' which we tried, and typically it worked fine, however it's done this a couple of times and I really don't want to pass this problem to the new owner. Any ideas what part I'll need to replace to stop this happening? Big thanks in advance for even reading through this.

 

[Robbostanhill]

Diagnosis required

Hi guys, I recently decided to sell my van, and I think it might have heard me because it's since started developing a couple of small problems that I really would like to have fixed before she goes!

I have an S reg diesel Mercedes Vito van. It starts perfectly fine from cold, glow plugs warm up fine and the light goes out, and it starts first time. however when it's been running a while and I stop for a short while, for example to get diesel, it wont start properly.

When attempting to start at the fuel station, the glow plug light wont go out, even after 5 mins. If I attempt to start it anyway the starter motor turns just fine and it sounds like it's going to start, however it just wont catch. If I put the accelerator flat to the floor and attempt to start it, it turns over and runs, but it rumbles at just above stall point and letting my foot off the accelerator makes it cut out.

I eventually got it started by getting my sister to start it with the accelerator flat to the floor so it rumbled, and manually opening the throttle from under the bonnet. After revving it a few seconds, I let it go and the van ran as normal.

My local mechanic said 'I'll need to see it do it before I can try to fix it' which we tried, and typically it worked fine, however it's done this a couple of times and I really don't want to pass this problem to the new owner. Any ideas what part I'll need to replace to stop this happening? Big thanks in advance for even reading through this.

Get it plugged into STAR and have the system checked to get to the right failure the easy way

 

[Frontstep]

Isn't this a CPS fault ?
Crank position sensor.

 

[Mark@RMK]

Star diagnostics - on an 1998 108d isn't going to give much information about the engine because it doesn't have an ECU!

Pump or injectors!

 

[ELGRINGO]

non start

As above had several with same fault need to carry out deisel injector leak of test.

 

[Roxie]

Non cdi.

If the glow plug light stays on then this is an indicator that the imobaliser has not released the coded fuel valve.

Star might be able to help but this is a WSP fault as non CDI

It could be a key fault or similar. I have known a couple of fuel valves fail but they are usually bullet proof this is why no one knows about them.

 

[television]

CPS sounds dead right for this fault, the engine block will get hotter when stopped and enough to show a fault in the CPS,,it has to be that and so simple to change

 

[Vixser]

Amazing, thanks guys.

I went away for the weekend after posting this, and the Van broke down on a ferry. Very embarrassing! It's now developed into a fault when cold also, she just generally doesn't like to start sometimes and the throttle doesn't seem to have any effect. Maybe it was just coincidence the first couple of times.

Anyway, I took it to a garage to get diagnostics fluff done, and they said it's too old for their kit. The only place we can find that has the kit, quoted £50 to run diagnostics and £85 for an injector test and they can fit me in in about a week. This is fine if it needs it, but obviously if I can DIY a few tests and fix it myself, it'll be quicker, cheaper and far more satisfying.

I'll check out the things mentioned, the CPS I think being my first thing to look at, I've heard it mentioned as a possibility a few times now. Any sure fire way to test if one is broken?

I'll keep you updated on my findings and solutions.

 

[television]

Yes the CPS measures between 800 ohms and 1k ohm, when not working they measure almost infinity

 

[Vixser]

Hi guys, I spent about half an hour trying to find the CPS, both on the van and trolling the net for a picture, but can't seem to see it. Whereabouts should I be looking? Anyone have a good description or a photo?

It's a 1999 VITO 108 D (2.3 Litre diesel)

 

[Vixser]

Non cdi.

If the glow plug light stays on then this is an indicator that the imobaliser has not released the coded fuel valve.

Star might be able to help but this is a WSP fault as non CDI

It could be a key fault or similar. I have known a couple of fuel valves fail but they are usually bullet proof this is why no one knows about them.

It's been to a Garage and they couldn't read it with the diagnostic kit. She doesn't have an alarm or immobiliser, and sometimes persistence in holding the ignition on and the starter motor turning seems to help. Bad for the starter motor, but at least she starts to take to the garage.

Could the fuel valve be not-released for any other reason? What's a key fault?

 

[Roxie]

Had fun looking for cps? It still doesn't have one.

As I can't see vehicle I can not be 100% but I am sure that you have an imobaliser. You should have a chip in the key. If so as I have already said you will have a fault with the system. I am of the opinion that you could have a fault with your coded fuel valve.

You could take it off and bypass it if you have the ability to adapt the fittings. Otherwise you will have to get it to a star diagnosis to check the wsp.

 

[Vixser]

Had fun looking for cps? It still doesn't have one.

As I can't see vehicle I can not be 100% but I am sure that you have an imobaliser. You should have a chip in the key. If so as I have already said you will have a fault with the system. I am of the opinion that you could have a fault with your coded fuel valve.

You could take it off and bypass it if you have the ability to adapt the fittings. Otherwise you will have to get it to a star diagnosis to check the wsp.

The key is an entirely metal one, no plastic casing that could hide a chip of any sort, and there's nothing unusual taped anywhere in the cab or engine bay, we've had it a year and poked around it plenty.

I was of the understanding that if the coded fuel valve was faulty, it wouldn't run at all, and you couldn't bump start it. Would it have only been a problem when the engine was hot?

Because of the cold and bank holiday weekend, and a million other things, our Van can't be booked in for diagnostic for a week or so. Without an immobiliser, would it still likely be a problem with the coded fuel valve? If I take it off, is there a way to prove it's faulty?

What's the WSP?

Thanks guys, really appreciate the pointers

 

[Roxie]

wsp is the factory fitted imobiliser if you dont have a chip in the key you dont have one, nor do you have a coded fuel valve.
You are left with basic mechanics ( compression etc ) and the fuel pump. Does the vacuum stop release?

 

[Roxie]

I thought all S reg vans and newer had factory fitted immobilisers. If you put the chassis no. up I can have a look at your data card.

 

[Mark@RMK]

It doesn't have a cps, or an ECU!




Mark

 

[Vixser]

Hi guys, sorry for the absence, we found a place that could look at the van and went away for the Easter weekend.

Thanks for the offer to check the data card Roxie, when we get the van back this weekend I'll have a look for the chassis number.

I had a call to say that the problem is looking like EGR fault, they'll get back to me later with a quote to fix it. Having heard many stories of vans being diagnosed and many different 'fixes' not solving the problem, just wanted to know if this diagnosis at least potentially fits?

We will be collecting it later to be able to take it and get some bodywork repaired this weekend, and arranging to take it back mid next week, in the meantime is there anything I could do as a temp fix so it'll start all weekend? Block off the EGR perhaps?

 

[Vixser]

They said it wouldn't take them long so I left it with them to do. They just called and said the EGR wasn't actually blocked up, and looked pretty clean so that's not the cause. They mentioned something about a temperature sensor, but basically it's back to the drawing board ;-(

 

[tyg]

Morning everyone need some mechanical advice put the key in the van (98 vito) this morning all the electrics came on I counted to 10 turned the key to start it and it wouldn't turn over at all did it 3 times before it started and same thing happened when I dropped the Mrs off at work any ideas?