DaveRob:
Off the top of yer bonce, do you happen to know if the fan is linked up with any of the problems we've been discussing? Just that it's always worked perfectly until the other night when I was limping home and I nearly boiled over. It used to bubble like a kettle before but I changed the header tank cap and that seemed to fix it, so I don't think it a pressure problem.
Cheers buddy!
Fuel Pump Grief!
Started by
minicooper1.3i
, Jun 16 2008 10:40 AM
45 replies to this topic
#31
minicooper1.3i
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Posted 27 June 2008 - 11:54 AM
#32
minicooper1.3i
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Posted 27 June 2008 - 07:43 PM
Ok folks! Here we go again.
I disconnected the main earth strap from the body under the brake servo and behind the ECU and cleaned the bolt, washer and tag on the end of the wire. Reconnected and tested the earth between the tag and the ECU body and the engine and it checks out OK. Next I unplugged the relay module and made a small incision in the sleeve of the only black wire. I then tested between the exposed copper and the pin on the plug, all ok. Then tested between the exposed copper and earth. Nothing.
Then I unplugged the ECU and this is where it get complicated. I couldn't find any pin numbers on the plugs for starters. But......there are 3 thick black wires on the red plug and 1 thick black wire on the black plug. According to the Rover circuit diagrams, there should be 4 earth wires on the ECU (there are a couple of thin black wires too) Two of them on the red plug go to earth. The third is dead. The single on the black plug goes to earth. I stripped back the sleeving on the dead black wire and tested the copper to earth. Still nothing. What I (stupidly) didn't do was test between the dead thick black wire on the ECU and and the dead THIN black wire on the plug to the relay module. Can they be the same wire, even though they're different sizes?
Sorry for waffling on a bit, but I'd rather give the whole story in the desperate attempt to stumbling on the solution.
Thanks again if you've manages to read this far without falling asleep!
I disconnected the main earth strap from the body under the brake servo and behind the ECU and cleaned the bolt, washer and tag on the end of the wire. Reconnected and tested the earth between the tag and the ECU body and the engine and it checks out OK. Next I unplugged the relay module and made a small incision in the sleeve of the only black wire. I then tested between the exposed copper and the pin on the plug, all ok. Then tested between the exposed copper and earth. Nothing.
Then I unplugged the ECU and this is where it get complicated. I couldn't find any pin numbers on the plugs for starters. But......there are 3 thick black wires on the red plug and 1 thick black wire on the black plug. According to the Rover circuit diagrams, there should be 4 earth wires on the ECU (there are a couple of thin black wires too) Two of them on the red plug go to earth. The third is dead. The single on the black plug goes to earth. I stripped back the sleeving on the dead black wire and tested the copper to earth. Still nothing. What I (stupidly) didn't do was test between the dead thick black wire on the ECU and and the dead THIN black wire on the plug to the relay module. Can they be the same wire, even though they're different sizes?
Sorry for waffling on a bit, but I'd rather give the whole story in the desperate attempt to stumbling on the solution.
Thanks again if you've manages to read this far without falling asleep!
#33
DaveRob
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Posted 28 June 2008 - 06:49 AM
I disconnected the main earth strap from the body under the brake servo and behind the ECU and cleaned the bolt
Im a little confused here.... the fat copper main earth strap runs from the engine bulkhead steady bolt to the engine block.... BUT the ECU and sensor earths are to the left of this.... Their are a two or three thin black wires terminated in ring tags screwed to the bulkhead with a cross head machine screw...
Looking at Haynes for the MPi circuits it looks like their are 4 earths. 3 labled black all terminating at the same point as the oxygen sensor from 158/16 and 158/24. The other is from the other plug at C159/21 all of these should have continuity to each other and be strapped to the oxygen sensor earth point on the bodywork.... the 4the black you mention on C158/23 is actually a screen connection for the sensor wires.... it wont go to chassis but is attached to the ground plane in the ECU itself and will not be connected to the chassis or the other 3 black wires. The denotion C158 and C159 is actually Connector 158 and connector 159 the number after the / mark is the pin number of the specific connector.... the simplest way to find the pin numbers is to find a colour you can relate to the diagram like pink green on C159/15 which is the CTS and then you know what number pin you are looking at on the actual plug, ( sorry I had forgotton we are talking MPi earlier but the loom colours are very similar and so is the wiring)......
test between the dead thick black wire on the ECU and and the dead THIN black wire on the plug to the relay module
If you have a dead THICK black....where is it from in the ecu plug ie what C15X/XX a thick black suggests an earth and if its from either C159/21, C158/16 or C158/24 then this will definatly need a bond to all the others AND to chassis earth AND to the oxy sensor earth......Looking at Haynes this dosnt show a black wire to the relay module. This could be a screen wire although it could be part of the alarm circuit which isnt denoted in Haynes.....or could be an earth.... if its V thin id suggest screen or alarm.... if its thick id suggest earth but cant see where in the diagrams
Back later
Rob
Im a little confused here.... the fat copper main earth strap runs from the engine bulkhead steady bolt to the engine block.... BUT the ECU and sensor earths are to the left of this.... Their are a two or three thin black wires terminated in ring tags screwed to the bulkhead with a cross head machine screw...
Looking at Haynes for the MPi circuits it looks like their are 4 earths. 3 labled black all terminating at the same point as the oxygen sensor from 158/16 and 158/24. The other is from the other plug at C159/21 all of these should have continuity to each other and be strapped to the oxygen sensor earth point on the bodywork.... the 4the black you mention on C158/23 is actually a screen connection for the sensor wires.... it wont go to chassis but is attached to the ground plane in the ECU itself and will not be connected to the chassis or the other 3 black wires. The denotion C158 and C159 is actually Connector 158 and connector 159 the number after the / mark is the pin number of the specific connector.... the simplest way to find the pin numbers is to find a colour you can relate to the diagram like pink green on C159/15 which is the CTS and then you know what number pin you are looking at on the actual plug, ( sorry I had forgotton we are talking MPi earlier but the loom colours are very similar and so is the wiring)......
test between the dead thick black wire on the ECU and and the dead THIN black wire on the plug to the relay module
If you have a dead THICK black....where is it from in the ecu plug ie what C15X/XX a thick black suggests an earth and if its from either C159/21, C158/16 or C158/24 then this will definatly need a bond to all the others AND to chassis earth AND to the oxy sensor earth......Looking at Haynes this dosnt show a black wire to the relay module. This could be a screen wire although it could be part of the alarm circuit which isnt denoted in Haynes.....or could be an earth.... if its V thin id suggest screen or alarm.... if its thick id suggest earth but cant see where in the diagrams
Back later
Rob
Edited by DaveRob, 28 June 2008 - 07:54 AM.
#34
minicooper1.3i
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Posted 28 June 2008 - 11:25 AM
Cheers Rob.
The earth strap I was referring to is to the left of the brake servo and bolts to the body above the brake pressure splitter. It joins into the main loom under the ECU. It's just a single thick wire, probably about 3mm diameter.
I'm going to take some pictures this afternoon and I'll photoshop them to indicate specific pins and wires. I think that's the best way to avoid any further confusion.
Thanks for all your help. I'll post back soon.
Cheers!
The earth strap I was referring to is to the left of the brake servo and bolts to the body above the brake pressure splitter. It joins into the main loom under the ECU. It's just a single thick wire, probably about 3mm diameter.
I'm going to take some pictures this afternoon and I'll photoshop them to indicate specific pins and wires. I think that's the best way to avoid any further confusion.
Thanks for all your help. I'll post back soon.
Cheers!
#35
minicooper1.3i
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Posted 28 June 2008 - 02:12 PM
I THINK I MIGHT HAVE SOLVED IT!!!!!!!!!!!!!
After managing to work out which pin is which on the ECU plugs (thanks Rover for numbering them.....NOT), I discovered that the dud earth on the ECU plug is the Screened Earth, which links the screen sheath on three sensor wires together and to ground. As I lifted it up the plugs to try and trace the wire.....this happened.
As you can see (although it's a little out of focus) the screen is a lovely green colour and very fragile. As you can see towards the bottom left, one of them even broke off as I moved it
Way to go with the quality wiring there Rover!
Going to attempt a clean up and reconnection operation a bit later this afternoon.
Wish me luck
After managing to work out which pin is which on the ECU plugs (thanks Rover for numbering them.....NOT), I discovered that the dud earth on the ECU plug is the Screened Earth, which links the screen sheath on three sensor wires together and to ground. As I lifted it up the plugs to try and trace the wire.....this happened.
As you can see (although it's a little out of focus) the screen is a lovely green colour and very fragile. As you can see towards the bottom left, one of them even broke off as I moved it
Way to go with the quality wiring there Rover!
Going to attempt a clean up and reconnection operation a bit later this afternoon.
Wish me luck
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28062008398.jpg 400.88K
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#36
BoyracerAU
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Posted 28 June 2008 - 02:38 PM
That's hopefully where your problem is. Look forward to hearing how you went.
Here's hoping for a good result!
Here's hoping for a good result!
#37
DaveRob
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Posted 28 June 2008 - 03:25 PM
......report back soon...Rob
#38
minicooper1.3i
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Posted 28 June 2008 - 08:15 PM
Right.
Cleaned up the exposed screen cable from the two that are still connected. Stripped back the sleeving on the third, unplatted the screen and crimped on a bullet connector. Checked every part of the connections for continuity and everything looked good. Rejoined it back to the ECU and...........(drum roll please).........
all happened.
Thinking that, as it would appear in the circuit diagrams, the screen earth does not go directly to ground, but via a ground link in the ECU and out of one of the other ECU earths, I extended the new bit of wire and took it straight to ground. Aaaaannnnndddddddd............(bigger drum roll please).......an even BIGGER all happened.
Have now given up and am sitting quietly in a corner crying into a pint
Cleaned up the exposed screen cable from the two that are still connected. Stripped back the sleeving on the third, unplatted the screen and crimped on a bullet connector. Checked every part of the connections for continuity and everything looked good. Rejoined it back to the ECU and...........(drum roll please).........
all happened.Thinking that, as it would appear in the circuit diagrams, the screen earth does not go directly to ground, but via a ground link in the ECU and out of one of the other ECU earths, I extended the new bit of wire and took it straight to ground. Aaaaannnnndddddddd............(bigger drum roll please).......an even BIGGER
all happened.Have now given up and am sitting quietly in a corner crying into a pint
#39
DaveRob
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Posted 29 June 2008 - 05:55 AM
Dont get too disheartened tho.... a pint usually works well...lol
You mentioned
the dead thick black wire on the ECU
The screens for the sensor cables prevent interference and electrical noise messing with the signals..... they are bonded to a ground plane in the ECU and may or may not be referenced to the shell earth.... my guess is prob NOT and they have their own reference in the ECU.... they are only bonded at one end,...... due to the fact that you can get potential differences if you fix both ends that cause issues with harmonics and phase locks in electrical terms.... so the screens were not going to be a major source of this fault but rather an issue that needed dealing with.
Have a look at the other earths... you mention one in the ecu plug doesnt go to ground....which one is this?...what pin number and plug number....
If their is a dead black wire fix this first.... if not then its time to start from the begining and doing each circuit step by step..... its always difficult doing this over the internet as you cant see whats happening..... but the circuit to make an engine start ... even in an injection car.... isnt that difficult.... it needs the right sequence and things to be powered up in the right order with signals from sensors at the right time..... fix the dead wire then get back to us and we can chip in again.
Rob
You mentioned
the dead thick black wire on the ECU
The screens for the sensor cables prevent interference and electrical noise messing with the signals..... they are bonded to a ground plane in the ECU and may or may not be referenced to the shell earth.... my guess is prob NOT and they have their own reference in the ECU.... they are only bonded at one end,...... due to the fact that you can get potential differences if you fix both ends that cause issues with harmonics and phase locks in electrical terms.... so the screens were not going to be a major source of this fault but rather an issue that needed dealing with.
Have a look at the other earths... you mention one in the ecu plug doesnt go to ground....which one is this?...what pin number and plug number....
If their is a dead black wire fix this first.... if not then its time to start from the begining and doing each circuit step by step..... its always difficult doing this over the internet as you cant see whats happening..... but the circuit to make an engine start ... even in an injection car.... isnt that difficult.... it needs the right sequence and things to be powered up in the right order with signals from sensors at the right time..... fix the dead wire then get back to us and we can chip in again.
Rob
#40
minicooper1.3i
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Posted 29 June 2008 - 09:53 AM
Hey Rob
The dead black wire on the ECU plug was the screen earth. The other three on pins (red plug) 158/16, 158/24, and (black plug) 159/21 are all fine. The screen earth is 158/23. I'm thinking along the same lines as you. If I can get a second pair of hands today, I'm going to start again and see if the 12v offload and 0v onload fault is still there.
If it is, it would appear that somewhere there is a crudded up connection that jut can't carry any current. By the way, I checked the earth point on the rear near side light cluster which is where the fuel pump grounds to and it's fine. Still, going to double check everything anyway.
The dead black wire on the ECU plug was the screen earth. The other three on pins (red plug) 158/16, 158/24, and (black plug) 159/21 are all fine. The screen earth is 158/23. I'm thinking along the same lines as you. If I can get a second pair of hands today, I'm going to start again and see if the 12v offload and 0v onload fault is still there.
If it is, it would appear that somewhere there is a crudded up connection that jut can't carry any current. By the way, I checked the earth point on the rear near side light cluster which is where the fuel pump grounds to and it's fine. Still, going to double check everything anyway.
#41
minicooper1.3i
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Posted 29 June 2008 - 11:55 AM
DONE IT!!!!!! 
Although it is rather a hollow victory as I also feel bloody stupid 
Was just testing the pump again, then moved on to the inertia switch when I noticed the bodged up repair shown here.
29062008400.jpg 396.05K
46 downloads
And guess where that wire goes. Yep, from the fuel pump relay to the inertia switch. The most annoying thing is, is that I'd noticed it before a few months ago when I had the engine out and was thinking then that I should redo it properly, but forgot all about it. Anyway, the top of the blue wire was coverd in crud and dangling in mid air, doing sod all. Gave it a quick clean, stuffed it back in again and it fired straight up. I HATE BODGING BUMHEADS! DO IT PROPERLY OR DON'T DO IT AT ALL!!!!!! (rant over)
Going to go out when it stops peeing it down a do it properly.
My esteemed thanks to you all for sticking with me through this and for offering so much assistance.
Rob, CamBiker, if you're ever down in the Beddy area, I think you may find a pint or two with your names on
Cheers all!
Although it is rather a hollow victory as I also feel bloody stupid Was just testing the pump again, then moved on to the inertia switch when I noticed the bodged up repair shown here.
29062008400.jpg 396.05K
46 downloadsAnd guess where that wire goes. Yep, from the fuel pump relay to the inertia switch. The most annoying thing is, is that I'd noticed it before a few months ago when I had the engine out and was thinking then that I should redo it properly, but forgot all about it. Anyway, the top of the blue wire was coverd in crud and dangling in mid air, doing sod all. Gave it a quick clean, stuffed it back in again and it fired straight up. I HATE BODGING BUMHEADS! DO IT PROPERLY OR DON'T DO IT AT ALL!!!!!! (rant over)
Going to go out when it stops peeing it down a do it properly.
My esteemed thanks to you all for sticking with me through this and for offering so much assistance.
Rob, CamBiker, if you're ever down in the Beddy area, I think you may find a pint or two with your names on
Cheers all!
#42
BoyracerAU
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Posted 29 June 2008 - 12:17 PM
Congrats!
Now you can have a pint and actually enjoy it.
Now you can have a pint and actually enjoy it.
#43
minicooper1.3i
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Posted 29 June 2008 - 12:50 PM
Congrats!
Now you can have a pint and actually enjoy it.
Yeah!
Last nights was a bit salty
Still kicking mysefl though for missing something so bleedin' obvious
#44
Sprocket
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Posted 29 June 2008 - 02:18 PM
Glad you fixed it
Most of this has already been covered, i just need to get round to organising the info for instance the post below only a few weeks ago. The ECU will only handle low current grounds, the injector and ignition coil grounds. The fuel pump ground is infact part of the body loom and not he engine loom. Not sure where it grounds to, but there are only three ground points for the body loom. One on the bulkhead crossmember triangular suport on the RIGHT hand side of he engine bay, opposite side from he ECU/ engine loom grounds. Second on the nearside rear light cluster fixing bracket in the boot, and the third on the offside rear light cluster in the boot.
I have also said it before, fuel pump problems are becoming more and more common, and a lot of them seem to be down to either the relay pack or the wiring itself. There are two 13 way and one two way connectors that the power supply for the fuel pump has to pass through, and these are close to the limit of the connectors current carrying capebilities. Looking a your picture, it would appear that this may have been a problem already, hense the dodgy wiring to bridge the connector.
Dodgey wiring is the evil of all evils
Most of this has already been covered, i just need to get round to organising the info for instance the post below only a few weeks ago. The ECU will only handle low current grounds, the injector and ignition coil grounds. The fuel pump ground is infact part of the body loom and not he engine loom. Not sure where it grounds to, but there are only three ground points for the body loom. One on the bulkhead crossmember triangular suport on the RIGHT hand side of he engine bay, opposite side from he ECU/ engine loom grounds. Second on the nearside rear light cluster fixing bracket in the boot, and the third on the offside rear light cluster in the boot.
I have also said it before, fuel pump problems are becoming more and more common, and a lot of them seem to be down to either the relay pack or the wiring itself. There are two 13 way and one two way connectors that the power supply for the fuel pump has to pass through, and these are close to the limit of the connectors current carrying capebilities. Looking a your picture, it would appear that this may have been a problem already, hense the dodgy wiring to bridge the connector.
Dodgey wiring is the evil of all evils
What is the low voltage you were reading? and how does it compare to the battery voltage
Disconnect the wiring at the tank end and measure the volts, if the pump is faulty it could pull the voltage down. if there is no difference with or without the pumop connected, there emay be corrosion on any number of connectors, inertia switch relay pack or fuse. It could also be a broken wire
#45
minicooper1.3i
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Posted 29 June 2008 - 02:19 PM
Just done a proper fix on the dodgy connector. The pins in the connector have actually burnt out, which is a little worrying. Now I'm wondering what caused it to burn out in the first place. Unless somebody used the wrong type of fuse before.
Got to say though, the bodged bit of wire was so thin, I reckon it would probably glow when the juice was on. Maybe it was a DIY engine bay light.
Anyway, just been out for a spin and pulled up next to a cute girl in a BRG Cooper Sport at the lights. She was obviously a proper Mini driver and we ended up having a great va-va-vroom up the bypass. Shame the sportspacks are slower
Got to say though, the bodged bit of wire was so thin, I reckon it would probably glow when the juice was on. Maybe it was a DIY engine bay light.
Anyway, just been out for a spin and pulled up next to a cute girl in a BRG Cooper Sport at the lights. She was obviously a proper Mini driver and we ended up having a great va-va-vroom up the bypass. Shame the sportspacks are slower
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