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Smartroman

Wont start again after idling fine for 5 minutes

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Hello all, my 450cdi turned itself off after 5 minutes of running with fresh alternator and serpentine belt. After it turned itself off, it cranked, but wouldn't start afterwards. Any suggestions? Everything seems in place. 

 

Quick update: Same thing happened today. Fuel pumping through both send and return lines. Ran for a few minutes, blip of gas, and engine dies. Attempts to fire at first crank rotation, but continues cranking with no catching. Exact same thing happened one year ago, and car hasn't been started since then, until today. It seems to have both fuel and spark. Could this be a problem with air- fuel mixture?

 

Edited by Smartroman
More specific.

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fuel pump probably isnt working

 

check brown connector on back of sam unit (fuse box type thing above drivers left foot)

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The pump is fairly loud, you should hear it run for about 4 seconds when you turn the ignition on. If you can't hear anything, refer to above post on the SAM harness.

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All of my no starts have been due to bad grounds in the engine bay.

I hooked a ground wire direct to the battery and then the engine block, with a second wire from the block connection to the group of wires that are on a ground pin on the body that is on the drivers side closest to the seats once you have the engine cover off.

Has stopped my no starts for now.

There's a braided ground wire that runs between the motor and bumper underneth and back towards the front that there's many posts about on this forum that gets corroded or breaks apart can cause a lot of electric gremlins too even if it looks good.

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Posted (edited) · Report post

Update: The car started after many cranks, ran for 2 minutes, and when I gave it a little rev, it bogged and died. Wouldn't start again, and the only sign of any combustion was on the first turn-over of every 4 second cranking attempt.

 

Checked for fuel delivery where the fuel filter would be on the gas model (passenger rear wheel well, no fuel filter in that location on my Cdi) and the pump was pumping fuel during priming and cranking with a steady stream of fuel. When I reconnected the fuel line, I could see the fuel flowing in the send and return lines at the top of the engine. 

 

My glow plug light is working. What should I check for next? Injectors? Replacing water separation tank/fuel filter/ fuel pump?

 

The diesel that was in it also looked just fine, for being about 2 years old. But I emptied the tank and will put fresh diesel in just in case.

 

 

Edited by Smartroman
Edited error

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Posted (edited) · Report post

On 6/3/2019 at 10:12 PM, BWM said:

All of my no starts have been due to bad grounds in the engine bay.

I hooked a ground wire direct to the battery and then the engine block, with a second wire from the block connection to the group of wires that are on a ground pin on the body that is on the drivers side closest to the seats once you have the engine cover off.

Has stopped my no starts for now.

There's a braided ground wire that runs between the motor and bumper underneth and back towards the front that there's many posts about on this forum that gets corroded or breaks apart can cause a lot of electric gremlins too even if it looks good.

 

I checked and the grounds seem fine... but I will check again. Thanks.

 

Edited by Smartroman

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Quick update: Same thing happened today. Fuel pumping through both send and return lines. Ran for a few minutes, blip of gas, and engine dies. Attempts to fire at first crank rotation, but continues cranking with no catching. Exact same thing happened one year ago, and car hasn't been started since then, until today. It seems to have both fuel and spark. Could this be a problem with air- fuel mixture?

 

Is your 450 a diesel model, or is it a 451? You mention gas and spark.

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Just a simple quick question...?
Did you disconnect your battery when you changed your alternator or maybe you shorted out a wire going to your ECU.....I shorted or discharged my ECU while trying to clean pins.....killed it dead, a simple flash and done.  Just a thought? Any chance at all..?    I cleaned my pins with plastic brush like a tooth brush and sensor cleaner, nothing metalic at all and it did it.....so just a thought...possible?

 

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7 hours ago, Wild! said:

Quick update: Same thing happened today. Fuel pumping through both send and return lines. Ran for a few minutes, blip of gas, and engine dies. Attempts to fire at first crank rotation, but continues cranking with no catching. Exact same thing happened one year ago, and car hasn't been started since then, until today. It seems to have both fuel and spark. Could this be a problem with air- fuel mixture?

 

Is your 450 a diesel model, or is it a 451? You mention gas and spark.

It is a 450 diesel. Sorry, I meant to say glow plug. And I mentioned gas earlier in reference to the location where I disconnected the fuel line to check for flow - where the fuel filter would have been on the gas engine. Sorry for the confusion again!

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4 hours ago, Willys said:

Just a simple quick question...?
Did you disconnect your battery when you changed your alternator or maybe you shorted out a wire going to your ECU.....I shorted or discharged my ECU while trying to clean pins.....killed it dead, a simple flash and done.  Just a thought? Any chance at all..?    I cleaned my pins with plastic brush like a tooth brush and sensor cleaner, nothing metalic at all and it did it.....so just a thought...possible?

 

Ooph. That is hard to say. I know I had to replace the old battery because it had been shot dead and I couldn’t recharge it. I believe it would have been out of the car, but there is a 10% chance that could have happened. How did you find your ecu was shot- how did the car behave afterwards? And was it difficult to replace?

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2 hours ago, Smartroman said:

Ooph. That is hard to say. I know I had to replace the old battery because it had been shot dead and I couldn’t recharge it. I believe it would have been out of the car, but there is a 10% chance that could have happened. How did you find your ecu was shot- how did the car behave afterwards? And was it difficult to replace?

It wouldn't start....period....easy-ish to replace as all but one screw snapped off when trying to undo it......then I simply bought a secondhand one from wrecker and installed it with plenty of my favorite goo....silicone and let it dry....I couldn't see any damage and I took the ECU completely apart, just being nosey as I knew it was toast....I just wanted to see if I could see any damaged components and try and replace them...nothing.  You need to get the new to you ECU programed in by a STAR  as it will need to be introduced to the other computers or it won't work.  Sorry.

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17 hours ago, Smartroman said:

 

I checked and the grounds seem fine... but I will check again. Thanks.

 

Yep gad my grounds off 3 times an cleaned each time and every time if I used a jumper wire it would start, once cleaned would run mint for 10-14 days then no start.

CAN'T be the grounds I just cleaned them but take em off or jump em from bat to ground and it would start for the next cycle.

Last time I ran a wire from battery to engine block with soldered on eyes.

One from engine block connected and soldered to each of the six ground wires.

And one wire block to a body ground point that I cleaned the paint off of body before attaching.

Sealed all connections with shrink wrap and sprayed body eye grounds with battery terminal cleaner.

It's been 4 weeks since I had a no start now

Just because they look clean don't make it clean.

I cleaned using a file then polished with sand paper.

Even though the main ground cable looks good and the connections triple cleaned I believe it's my main culprit hence the added grounds.

Take a booster cable and jump the battery to engine block and add a jumper from there to your cluster of ground wires.

Mine would try to start but didn't at the 1st try just a cple jugs then nothing.

Leave it an hr and it did it again.

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I too have had thius issue with grounds.....totally upsetting to say the least! Did everything you have done, minus the soldering of eyes, I just replaced them with new ones and shrink wrapped them and then sealed with dilectric grease before reinstalling....so far no more grounding issues....fingers crossed.  For such a electronically engineered little scooter, they really screwed it up in some ways.  Far too complicated and poor water protection. Personally I would have addressed this over marker lights before shipping it to North America especially to an area where salt is used to the max!

 

 

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21 hours ago, BWM said:

Yep gad my grounds off 3 times an cleaned each time and every time if I used a jumper wire it would start, once cleaned would run mint for 10-14 days then no start.

CAN'T be the grounds I just cleaned them but take em off or jump em from bat to ground and it would start for the next cycle.

Last time I ran a wire from battery to engine block with soldered on eyes.

One from engine block connected and soldered to each of the six ground wires.

And one wire block to a body ground point that I cleaned the paint off of body before attaching.

Sealed all connections with shrink wrap and sprayed body eye grounds with battery terminal cleaner.

It's been 4 weeks since I had a no start now

Just because they look clean don't make it clean.

I cleaned using a file then polished with sand paper.

Even though the main ground cable looks good and the connections triple cleaned I believe it's my main culprit hence the added grounds.

Take a booster cable and jump the battery to engine block and add a jumper from there to your cluster of ground wires.

Mine would try to start but didn't at the 1st try just a cple jugs then nothing.

Leave it an hr and it did it again.

This is awesome info. Where is the cluster of ground wires located? Going to give this regrounding a try.

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Also just got quoted $2500 for a new Blank ECU from Mercedes which would have to be ordered from Germany. Is there any way to re-flash one from another car, or re-program the one I have myself? Or to diagnose its’ misfunction in the first place? 

 

I’m impressed by all the responses so far. 

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You can buy a used one from the wreckers and get it flashed by a STAR system and there has to be someone in your area who owns one....simply ask......

 

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6 hours ago, Smartroman said:

This is awesome info. Where is the cluster of ground wires located? Going to give this regrounding a try.

They are about 1/3 the way across the engine bay from the drivers side under the floor pan right behind the drivers seat.

Can't see them without the cover off.

Before spending money on a bunch of parts that maybe the culprit try the simple things 1st.

From what I read it was running fine before you changed the bad alt.

I drove my smart a mile up the road to the store and back again when I pulled into the driveway found the belt laying there.

So I know for a fact a smart will run without an alternator.

The only thing you did was change it.

There must be something else you touched or a connection isn't being made be that a ground or a plug is what I would be spending 99% of my attn towards before ever thinking a part is in need of replacing.

We had a saying when I worked at an automotive electrical shop.

98.2% of electrical problems in cars are ground issues.

In truth more like 2/3rds are ground issues.

most of the rest is burnt or corrosion in wiring plug connectors.

With an odd broken wire thrown in just to keep ya pulling out your hair.

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I agree, with above also...check ECU for 2 green pins, 16 and 20  something near those...I think... they are at the end of the plug. IF you didn't unhook battery I';ll bet a good donut that you could have fried the ECU...BUT...I would follow the above advice first before spending on the expensive parts!    There are so many ground pins that really all should be tied together and not rely on grounding to a rusty or corroded body part...send them all to a single grounding wire or strap to the battery. But no-one is going to do that either, so we work with what we have.  It would be nice to have a diagram of all grounding points so we could go around and disturb them all to be 1000% sure they are all good. But we don't i don't think.....? Maybe we do..?

I agree to check all and any plugs that you could have touched while changing that frig'in alternator.. sorry to use the good language but I've also changed one recently and it wasn't fun. OR any that could have been stretched...? IF you are a dilectric grease user like I am, I have learned the hard way there is a limit you can use and not get it to conduct......I used to fill the plug/connection full and then squeeze it together having grease push out everywhere but thinking that no water could possibly get into the plug from now on. Only to learn it will conduct a very small amount and that is detectable but this electrical system......so just a smear with a children's paint brush is all i use not to coat just the contacts....probably what you are supposed to do in the first place but no-one says so.

Good luck and as the saying goes.....KISS   keep it simple stupid...lol    I was told way way back it's always likely to be the simple things that are the problem, so always check those first.

 

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13 hours ago, BWM said:

They are about 1/3 the way across the engine bay from the drivers side under the floor pan right behind the drivers seat.

Can't see them without the cover off.

Before spending money on a bunch of parts that maybe the culprit try the simple things 1st.

From what I read it was running fine before you changed the bad alt.

I drove my smart a mile up the road to the store and back again when I pulled into the driveway found the belt laying there.

So I know for a fact a smart will run without an alternator.

The only thing you did was change it.

There must be something else you touched or a connection isn't being made be that a ground or a plug is what I would be spending 99% of my attn towards before ever thinking a part is in need of replacing.

We had a saying when I worked at an automotive electrical shop.

98.2% of electrical problems in cars are ground issues.

In truth more like 2/3rds are ground issues.

most of the rest is burnt or corrosion in wiring plug connectors.

With an odd broken wire thrown in just to keep ya pulling out your hair.

I agree, I think something went wrong when changing the alternator... I had to drop the motor, so I’m sure I must have stretched a cable somewhere... 

 

the belt laying on your driveway must have been quite the kicker to find 😅

 

5 hours ago, Willys said:

I agree, with above also...check ECU for 2 green pins, 16 and 20  something near those...I think... they are at the end of the plug. IF you didn't unhook battery I';ll bet a good donut that you could have fried the ECU...BUT...I would follow the above advice first before spending on the expensive parts!    There are so many ground pins that really all should be tied together and not rely on grounding to a rusty or corroded body part...send them all to a single grounding wire or strap to the battery. But no-one is going to do that either, so we work with what we have.  It would be nice to have a diagram of all grounding points so we could go around and disturb them all to be 1000% sure they are all good. But we don't i don't think.....? Maybe we do..?

I agree to check all and any plugs that you could have touched while changing that frig'in alternator.. sorry to use the good language but I've also changed one recently and it wasn't fun. OR any that could have been stretched...? IF you are a dilectric grease user like I am, I have learned the hard way there is a limit you can use and not get it to conduct......I used to fill the plug/connection full and then squeeze it together having grease push out everywhere but thinking that no water could possibly get into the plug from now on. Only to learn it will conduct a very small amount and that is detectable but this electrical system......so just a smear with a children's paint brush is all i use not to coat just the contacts....probably what you are supposed to do in the first place but no-one says so.

Good luck and as the saying goes.....KISS   keep it simple stupid...lol    I was told way way back it's always likely to be the simple things that are the problem, so always check those first.

 

A ground wire diagram would be super helpful. Should I just inspect the ecu pins to see if they look fried? Or should I test them with a volt meter?

 

You guys rock. Thanks for all this great input.

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When I inspected my fried ECU there was nothing to find.....nothing outside or inside...looked like it should. I expected a fried capacitor or something after the discharge but nothing anywhere......really upsetting.....the new used one cost me $200...I got lucky!

 

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22 hours ago, Willys said:

When I inspected my fried ECU there was nothing to find.....nothing outside or inside...looked like it should. I expected a fried capacitor or something after the discharge but nothing anywhere......really upsetting.....the new used one cost me $200...I got lucky!

 

 

Wow, that’s super lucky. In my case it would be a total shot in the dark, because I’m not entirely sure it’s the ECU that I fried... but I guess I won’t know till I try it

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On 2019-06-06 at 11:24 PM, BWM said:

They are about 1/3 the way across the engine bay from the drivers side under the floor pan right behind the drivers seat.

Can't see them without the cover off.

Before spending money on a bunch of parts that maybe the culprit try the simple things 1st.

From what I read it was running fine before you changed the bad alt.

I drove my smart a mile up the road to the store and back again when I pulled into the driveway found the belt laying there.

So I know for a fact a smart will run without an alternator.

The only thing you did was change it.

There must be something else you touched or a connection isn't being made be that a ground or a plug is what I would be spending 99% of my attn towards before ever thinking a part is in need of replacing.

We had a saying when I worked at an automotive electrical shop.

98.2% of electrical problems in cars are ground issues.

In truth more like 2/3rds are ground issues.

most of the rest is burnt or corrosion in wiring plug connectors.

With an odd broken wire thrown in just to keep ya pulling out your hair.

 

I cant seem to find the cluster. I took the cover off, but the only thing that looks like a grounding pin is in the front of the drivers seat floor pan. There’s also a filter underneath, but no exposed wires or nuts that I can hook up the jumper cables to.

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That pin is almost directly under the rear of the drivers seat or maybe in he middle of it, tucked up on the back of a formed section of the floor pan.....it'll have maybe 6 wires running to it all light brown in colour from what I remember. You'll see it better if under vehicle and looking forwards. It's in front of the fuel filter area, a bit further towards the middle of the seat pan.

It is simply a pin that has so many wires with "O" Rings  and a single nut holding them all exposed.

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8 hours ago, Willys said:

That pin is almost directly under the rear of the drivers seat or maybe in he middle of it, tucked up on the back of a formed section of the floor pan.....it'll have maybe 6 wires running to it all light brown in colour from what I remember. You'll see it better if under vehicle and looking forwards. It's in front of the fuel filter area, a bit further towards the middle of the seat pan.

It is simply a pin that has so many wires with "O" Rings  and a single nut holding them all exposed.

That's where mine were, as I cut them off and relocated them and then made the extra connections giving them a direct connection to the engine block and battery.

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