No power to fuel pump list of symptoms with some diagnostics carried out

[Oggy997]

When I bought the CTR, I decided I was going to strip the clio and/or put the engine in a Mk1 shell. Over time I stripped bits, a mate need a coil pack and throttle body to diagnose some potential faults he had/has with his 182 so I duly obliged as the weather was crap and I wasn't really making any progress with the 172 myself.

Fast forward to a couple of months back, the car wouldn't start and the red 'immobiliser' light would remain solid (flashing with key removed) at first I put this down to it just being sat there dead for ages so charged the battery up.

Wire it up and there's no power to the fuel pump - as stated before I dont have the coil pack, so unsure if this break in the circuitry would cause the fuel pump not to prime? I plan to get the coil pack back asap but figured I'd fish for ideas while I was waiting - as this may not be the actual cause of the issue.

I get 12v to the fuel pump/coil pack relay and I swapped it out for the AC Compressor Relay as that wouldn't be needed fpr the fuel pump to prime and it's still not getting power.

I've checked the 3 pin lead to the coil pack, I get 9v on pin3. I've checked the fuel pump lead and don't get any voltage on any pin although I did see it shoot to 5v once, not sure why - movement was a bit restrictive in there and I couldnt really see what pin triggered that, I couldnt replicate it though.

Any ideas on where to go next / what else I can check? I plan to get the coil pack back this weekend.

​Thanks in advance.

 

[Oggy997]

To add, if I power on the car then try to turn it over, nothing, it doesn't crank but ifi try to crank the car from the key being in the off position it does try to crank three times then cuts out. Obviously I know it won't fire with no coil pack but I'm sure it done this with the coil pack present.

 

[Oggy997]

Can't edit posts in here? ECU gets 12v on pin 29 - Anyone know off hand what pins of the UCH the 'purple and white twisted pair' go to? (and their respective pins on the ECU)

 

[Oggy997]

More tests;

ECU gets 12v on both pin29/30

Checked for continuity between ECU and White multiplex connector in the fuse box. Both purple/white twisted pair check out. Need to check inside the car still but have to go to work now. For reference, pin 19/20 on multiplex had continuity with 57/27 (ECU) respectively.

 

[sburrell93]

Can't help much just now but I've got wiring diagrams at home, can have a check for you tonight when I get home from work if you like?

 

[Oggy997]

Any resources you can provide would be fantastic.

 

[sburrell93]

No problem mate i'll have a look later on then and let you know what I find.

 

[sburrell93]

Pins 19 and 20 are for the 'CAN L' and 'CAN H' signal's to the instrument panel. I believe they go to the fuel gauge.

Pins 30 and 29 on the ECU are a battery feed and a connection back to a fuse in the engine bay fusebox. The wire running from pin 29 to the fuse is spliced and there is a connection into the coil of the fuel pump relay. This relay then supplies the power to the fuel pump, fuel gauge and coil pack.

Pin 3 on the coil pack is the connection that comes from the fuel pump relay. So if you're getting power to that then I would say the relay isn't at fault. However, considering the relay supplies power to the fuel pump as well as the coil pack, I'd be inclined to check the continuity between that point and the fuel pump. Unfortunately I can't get any info on the pump itself so I can't advise what to check for.

Hope this helps a little though!

 

[Oggy997]

That's great thank you.

 

[Oggy997]

seems that I don't get 9v on pin 3 to the coil pack. Could have sworn I did.

, checked for continuity between purple and white at each socket. Ecu to multiplex, other side of multiplex to uch and it all checks out.

I've since noticed that pin 62 on the ecu is also a thicker twisted variant of purple and white wires, no continuity to the multiplug at all but i lose track of where it actually goes at the gear box as the insulation is really difficult to move.

 

[Oggy997]

Pin62 appears to be motorised throttle body.

 

[Oggy997]

It would appear that I have the exact same issue as here - http://www.cliosport.net/forum/show...s-and-dies-no-power-at-fuel-pump-or-coil-pack

I too have bridged the relay with a couple of spade connnectors and some AWG22 wire and the fuel pump does indeed prime and the coilpack gets 12v.

Next step

If it does you've found and proved the problem however its far from fixed and do not use the jumper as a permanent solution as the pump and coil pack will be continuously powered and run the battery flat... not to mention it will be a fire risk if you use a small gauge wire!

Now you need to work out why the relay isn't switching on/off - With a volt meter check that one side of the switch side has a permanent or ignition controlled +12v. If it does you will need to check the wiring between the relay board and the ECM Multiplug that is supposed to control the earth to ensure it is continuous as it is possibly damaged (or the ECM has developed a fault). If it doesn't have a +12v then you should check all fuses in the car and engine bay before then checking the power lines for wiring faults to.

 

[Oggy997]

I get 12v ignition on the 2 main feeds and continuity between the 2? switching pins - one to pin9 on the ECU, one to pin 36.

Now I have no idea what to do:/

 

[Oggy997]

I've now decided that I'm going to blow it up on November the 5th.

 

[MicKPM]

I've now decided that I'm going to blow it up on November the 5th.

I'll bring the chainsaw!

 

[Oggy997]

Ready when you are Mick

 

[Oggy997]

Finally got it onto a clip I sourced.

I'm no genius but that doesn't looks good. - Can anyone decipher that?

 

[callum_bell]

from what i can remember the 120 is the ECU and think 756 is airbag ECU, going by that diagram i think your missing a live feed to these computers. hence there red. i personally would be cutting open the engine loom between the engine fuse box and the ECU and looking for a broken or corroded wire.

For multi plex wiring they are usually two wires that are twisted together throughout the loom

For other computers im sure 1094 is ABS and 247 is instrument panel and 583 may possibly be the A/C and 645 is UCH

 

[bil_liser]

i've kinda lost track with all the posts.. im assuming the ecu is sirius34, in which case the immo from the Key>UCH>ECU is on the CANH-L wires (multiplex) and a solid red light on the dash is a UCH lock out flag, either the ECU isnt talking back to the UCH, or the ECU is reporting a critical fault to the UCH, or the UCH is just in safety lockout.

I would think on a s34, it wont prime the fuel unless it seems a crank signal, but im guessing without the ignition coil pack, it might possibly lock out.. i know for a fact the little 1.2 16v with the 5NR IAW ecu's will lock out starter with a solid red immo light on dash if there is a miss-fire or coil pack issue.

out of curiousity.. what happens with the red immo light if you disconnect the engine ecu complete? If you have a spare, although it wont start.. a code mis-match might give you a rapid flashing immo light.

120 is the ecu. 645 uch for sure. I'd get the coil pack on it. what faults did clip give you in unit 120? or didnt it go in?