Stranded

[Matt58]

Evening all, as title suggested I been stranded this evening, crank no start. My E55 W211 started lovely this am, drove to work with no issues, jumped back into car this evening and cranked strong but no start, I’ve had previous issues with battery drain (alarm siren removed) and have fairly recently changed rear battery and aux battery, I’ve also swapped CPS with genuine sensor. I’ve got day off on Friday so I’ll go and look at fuel pump relays ext, any ideas anyone? Thanks in advance. Matt.

 

[Jobsworth]

Check for fuel pressure in the fuel rail first. It has a valve in the end, driver’s side, that you can press to check if there is pressure. You may have to remove a cap, and mind your eyes. If you have pressure there, you WILL be able to tell, then the next likely culprit is spark. If you’ve replaced the crank sensor the next one is the cam sensor. If you have a code reader, use that too. See if you have codes.

 

[Matt58]

Check for fuel pressure in the fuel rail first. It has a valve in the end, driver’s side, that you can press to check if there is pressure. You may have to remove a cap, and mind your eyes. If you have pressure there, you WILL be able to tell, then the next likely culprit is spark. If you’ve replaced the crank sensor the next one is the cam sensor. If you have a code reader, use that too. See if you have codes.

Thanks for reply jobsworth, will check fuel pressure on Friday, and pull rear seat to see if I can listen to pumps and anything untoward, do I check fuel pressure whilst ignition is on? I’ve checked for codes with mb icarsoft, but only got code consumer shut off stage one 9051. Checked battery state which was 11.8 but I had cranked a few times, main battery only a year old, but may have been damaged with battery drain which turned out to be the alarm siren which was toast inside through water damage. One of the other times I had a no start was when I changed battery, I didn’t code new battery, and car eventually started, but felt more like immobiliser/key problem, I don’t really know.

 

[Matt58]

Thanks for reply jobsworth, will check fuel pressure on Friday, and pull rear seat to see if I can listen to pumps and anything untoward, do I check fuel pressure whilst ignition is on? I’ve checked for codes with mb icarsoft, but only got code consumer shut off stage one 9051. Checked battery state which was 11.8 but I had cranked a few times, main battery only a year old, but may have been damaged with battery drain which turned out to be the alarm siren which was toast inside through water damage. One of the other times I had a no start was when I changed battery, I didn’t code new battery, and car eventually started, but felt more like immobiliser/key problem, I don’t really know.

I’ve also changed plugs, wires and coil packs recently.

 

[Jobsworth]

Thanks for reply jobsworth, will check fuel pressure on Friday, and pull rear seat to see if I can listen to pumps and anything untoward, do I check fuel pressure whilst ignition is on? I’ve checked for codes with mb icarsoft, but only got code consumer shut off stage one 9051. Checked battery state which was 11.8 but I had cranked a few times, main battery only a year old, but may have been damaged with battery drain which turned out to be the alarm siren which was toast inside through water damage. One of the other times I had a no start was when I changed battery, I didn’t code new battery, and car eventually started, but felt more like immobiliser/key problem, I don’t really know.

Crank it first. Residual pressure will remain in the line for ages if the pump is working.

 

[Teego]

See if it'll jump start.

 

[Matt58]

Crank it first. Residual pressure will remain in the line for ages if the pump is working.

Will do.

 

[Matt58]

See if it'll jump start.

Thanks Teego, I’m charging my original battery up over the next 48hrs, but car started fine this morning after sitting for 5days whilst we’ve been on holiday. Are there any dangers when jump starting these cars? Any advice appreciated.

 

[Teego]

Thanks Teego, I’m charging my original battery up over the next 48hrs, but car started fine this morning after sitting for 5days whilst we’ve been on holiday. Are there any dangers when jump starting these cars? Any advice appreciated.

Not as long as you follow the procedure.

 

[Matt58]

Thanks Teego, I’m charging my original battery up over the next 48hrs, but car started fine this morning after sitting for 5days whilst we’ve been on holiday. Are there any dangers when jump starting these cars? Any advice appreciated.

Hi mate, you were spot on, zero fuel pressure from rail, 30amp fuse blown, replaced and she fired right up. Relay looked fine, but the connector that it fits into looked brown but not melted or dameged so has obviously got hot. I pulled the back seat up and removed cover plates expecting to find burnt connections, but I was amazed to find both sides in really good nick on original units. Do you have any advice on what my next step should be, other than change relay and clean or replace relay connector block? Thanks again. Matt.

 

[SpikyMikey]

If the relay terminals get corroded, then you can start getting a resistance building up.
A clean up of the terminals, a good squish of switch cleaner and then make/break the connection between plug and relay normally works.

 

[Matt58]

If the relay terminals get corroded, then you can start getting a resistance building up.
A clean up of the terminals, a good squish of switch cleaner and then make/break the connection between plug and relay normally works.

Thanks, I’ll get on it ASAP, should I still swap the relay?

 

[SpikyMikey]

The relay is probably OK; I might be tempted to splice in a new connector if you can get one .

 

[Matt58]

The relay is probably OK; I might be tempted to splice in a new connector if you can get one .

Yes I think that’s the way to go. Just drove home 12miles with no issues, other than ESP visit workshop? Any ideas. Also held the relay in my hand and it felt pretty hot, will test again when I’ve redone connector.

 

[Will]

Hi mate, you were spot on, zero fuel pressure from rail, 30amp fuse blown, replaced and she fired right up. Relay looked fine, but the connector that it fits into looked brown but not melted or dameged so has obviously got hot. I pulled the back seat up and removed cover plates expecting to find burnt connections, but I was amazed to find both sides in really good nick on original units. Do you have any advice on what my next step should be, other than change relay and clean or replace relay connector block? Thanks again. Matt.

Sounds like fuel pump may have started to seize up, drawing excess current?

 

[Matt58]

Sounds like fuel pump may have started to seize up, drawing excess current?

Yes could be, they are the original ones.

 

[Matt58]

The relay is probably OK; I might be tempted to splice in a new connector if you can get one .

Before I go any further, is it worth, and is it safe to consider putting in a 70 amp relay?

 

[Will]

Before I go any further, is it worth, and is it safe to consider putting in a 70 amp relay?

No

 

[SpikyMikey]

If the circuit is drawing more current than it's designed for (hence the hot relay and blown fuse) then you have to address the cause of that issue; to blow a 30A fuse, that's a major issue.

 

[Matt58]

No

Ok, just feeling the water and weighing up options. Am I right in thinking that the early models like mine had single relay, and later models had double relays to combat this problem, hence while some have swapped single 40 amp fuse for single 70amp? I had a pretty bad water leak in boot when I purchased car so that can’t have helped either, but alternately I think I’m looking at new pumps, but I’ll replace block, female terminals in the mean time and keep a very very close eye on things, I’ve left all the boot furniture out for the minute. Am I correct in thinking I need pumps and sender unit? Thanks, Matt.