I'd Like To Build A Complete Oe Engine Management Loom

[GLPoomobile 958]

I'm really starting to get in to all this wiring business as I've been messing about recently. Getting my hands dirty (so to speak) and reading various things on here has got me quite enthusiastic about this now.

 

So what I was thinking was, as a sort of indoors winter project, I might like to build a complete engine management loom for my Mi16 (I'm already making some improvements to my current shoddy loom). Not out of necessity, more just as a learning experience, but if I'm happy with the result I'll put it on the car.

 

I suppose really the only things I'm not sure about are the specific connectors used on the loom for sensors and the ECU.

 

Can you easily remove the terminals from the big ECU connector? Can you get new terminals to connect to new wiring and fit it back in to the ECU plug? What's involved in all this?

 

With the other connectors - Injectors/AFM/Throttle switch/ECU Temp sensor etc etc, do you need to get these from Pug/Citroen? Or from Bosch? Or are they fairly generic plugs that can be bought elsewhere (Junior Timer housing for example)?

 

I did ask a while back about the injector plugs and I think the answer was that you can use Junior Timer/Junior Power Timer stuff IIRC. Wouldn't hurt for that to be re-clarified in this topic though.

 

If I can find out how to replace all these plugs, then the rest should hopefully be childs play.

[Ryan 99]

The terminals come of out the ECU plug easily enough if you undo the screws holding it together, and iirc unclip some sort of plasic retaining clip that holds them all in place.

 

Most of the plugs on the engine are Junior Timer style plugs, although if I were replacing them I'd use the Junior Power Timer ones just for the nice quick-release action.

 

Terminals for most/all the plugs are in the Vehicle Wiring Products catalogue, but I'm sure you can get them elsewhere too.

[GLPoomobile 958]

The terminals come of out the ECU plug easily enough if you undo the screws holding it together, and iirc unclip some sort of plasic retaining clip that holds them all in place.

 

Most of the plugs on the engine are Junior Timer style plugs, although if I were replacing them I'd use the Junior Power Timer ones just for the nice quick-release action.

 

Terminals for most/all the plugs are in the Vehicle Wiring Products catalogue, but I'm sure you can get them elsewhere too.

 

 

Cool.

 

I seem to be a pretty regular customer of VWP at the moment (if anyone's interested, I highly recommend them, bloody great service!).

 

Keep the advice coming......

[saveloy 8]

You're mad. How's that for advice?!

[GLPoomobile 958]

You're mad. How's that for advice?!

 

Erm, it's s*it, and it's useless!! Don't give up your day job

 

What's mad about it? I'm wanting to do something practical to improve my wiring ability, so it seems a pretty good idea. I'm sure it can't be any worse than the dog's dinner of a 'rebuilt' loom that was fitted to my Mi. Providing the right connectors are used and good quality crimps are achieved (the right tools for the job used plus practise) then I really can't see how you can go wrong.

 

I'm still interested in hearing a bit more in depth about how to reterminate the ECU plug, if anyone cares to contribute

[Ryan 99]

I'll get the remains of my 8v loom out of the cupboard and take some pics of the ECU plug. It is dead easy though...

[maturin23 10]

I can't offer you any advice whatsoever - but I could well be tempted to do one of these after you've done yours

 

I was tempted to do the same, but didn;t look into to it very hard. From a practical point of view itcan't be that difficult, especially if it was fabricated alongside a known working loom as a template. One thing that did occur was that it may not be that easy to get hold of relative short lengths of cable in multiple colours, and I didn't fancy having a loom with one/two colours...

Edited November 23, 2007 by maturin23

[Powers 13]

There are definite benefits of having new wiring rather than the 15 year old original equipment.

Have you priced a loom up from Peugeot, if they sell them that is. As the materials alone will cost a fair bit, especially if you have to buy all the specialist tools and you want to make it aesthetically pleasing incorporating protective braid.

I recently built an engine loom from scratch for an Omex ECU and the costs can spiral, but in the long term i would definitely recommend it as not only do you learn the practical hands-on side of things but you also gain an understanding of how it all works. Making fault diagnosis and repair possible, which is very important if you are stuck on the side of the M4, in the pits mid session or midway through the final stage of the day.

 

I would also highly recommend vehicle wiring products for their excellent service.

Also I think Ryan has answered all your questions but feel free to ask some more!

[GLPoomobile 958]

One thing that did occur was that it may not be that easy to get hold of relative short lengths of cable in multiple colours, and I didn't fancy having a loom with one/two colours...

 

 

Oh yes it is dear boy Vehicle Wiring Products - cable in all manner of different colours at about 30p per metre

[GLPoomobile 958]

There are definite benefits of having new wiring rather than the 15 year old original equipment.

Have you priced a loom up from Peugeot, if they sell them that is. As the materials alone will cost a fair bit, especially if you have to buy all the specialist tools and you want to make it aesthetically pleasing incorporating protective braid.

I recently built an engine loom from scratch for an Omex ECU and the costs can spiral, but in the long term i would definitely recommend it as not only do you learn the practical hands-on side of things but you also gain an understanding of how it all works. Making fault diagnosis and repair possible, which is very important if you are stuck on the side of the M4, in the pits mid session or midway through the final stage of the day.

 

I would also highly recommend vehicle wiring products for their excellent service.

Also I think Ryan has answered all your questions but feel free to ask some more!

 

 

Well, without doing a full costing on it, off the top of my head I reckon it can be done for under £50. The tools are an extra cost, but they are an investment and I have some of those needed already. Most of the kit - cable, terminals, spiral wrap etc - are actually surprisingly cheap. Even Junior Power Timer plugs are not that expensive.

 

I dread to think what Pug would charge for a new loom, if they are even available. But to put it in to perspective, PWR sell reconned looms on eBay for about £170. My current loom was supposed to be rebuilt by the company who dd the engine conversion (before I bought the car) and the invoice says £300, and 2nd hand looms often cost £50 upwards on ebay. So if I can do it for £50 (minus tool costs) then I'd say that is reasonable.

[Powers 13]

Yes, for £50 that would be very good going. Keep us informed.

Oh and my engine loom has 32 different coloured/ combination of colours wires!

[maturin23 10]

Oh yes it is dear boy Vehicle Wiring Products - cable in all manner of different colours at about 30p per metre

 

I stand corrected!

 

If you fancy making two at the same time instead of one I'll chip in toward the tool costs

[Alastairh 47]

My thoughts:

 

The ecu plug. You on about re wiring it? Because i wouldn't. After all, bar the 405, the ecu stays in the cabin, and probably been dissconnected 3 times in its life. So this plug isn't the problem say as the oil temp sensor. In my eyes its just causing more work for yourself. And if your a pin wrong on that plug you'll be scratching your head for ages!

 

I would, get hold of another 8 valve loom, put them both on the work table, makea loom with all decent plugs, the ones that need slide on crimps, chuck some fully insulated ones on with ratchet crimps, and at the most, trace the pins to the plugs of the wires that you have to convert the 8 or so wires to make it work in a 205 and replace the wire from pin to pin so theres no solder, although i see nothing wrong with that if done properly, and of course tidy it up with wrap etc.

 

Al

[Beastie 1]

I make looms for all manner of vehicles as part of my job. It's not rocket science but it does require considerable thought and planning if you are going to make a neat job of it - getting the right cables branching off in the right combinations at the right location makes all the difference between a messy job (that still works) and a professional job which can look better than the original.

 

I'd make one more suggestion in addition to the comments already posted: Once the loom is made, consider obtaining a nice big wooden board and "pegging" your loom to it with nails at fixed reference points so that in future you can use the board to duplicate the loom quickly and without resorting to measuring the car again.

[GLPoomobile 958]

My thoughts:

 

The ecu plug. You on about re wiring it? Because i wouldn't. After all, bar the 405, the ecu stays in the cabin, and probably been dissconnected 3 times in its life. So this plug isn't the problem say as the oil temp sensor. In my eyes its just causing more work for yourself. And if your a pin wrong on that plug you'll be scratching your head for ages!

 

I would, get hold of another 8 valve loom, put them both on the work table, makea loom with all decent plugs, the ones that need slide on crimps, chuck some fully insulated ones on with ratchet crimps, and at the most, trace the pins to the plugs of the wires that you have to convert the 8 or so wires to make it work in a 205 and replace the wire from pin to pin so theres no solder, although i see nothing wrong with that if done properly, and of course tidy it up with wrap etc.

 

Al

 

I appreciate what you are saying about the ECU plug, it's a fair point. I think the same can be said of any of the connections in the loom though - get a bad connection and you could be scratching your head when I doesn't work. I think you need to appreciate that this isn't planned to be some rush job, quick fix etc etc. I'll be taking my time, and doing things carefully, because I can afford to. It's a learning experience after all, not a urgently needed solution to a problem.

 

The thing about leaving the ECU plug alone, well the point is that I want to replace the whole lot, not do half a job. So if I left the plug alone I'd have to cut the wires and splice the new wiring to them. You wouldn't expect that if you bought a custom loom, and so it's not kind of solution I 'm after.

 

I'll probably put a wanted add up for an Mi loom soon, I'm getting eager to do this now. If I do get it sorted, I'll write a comprehensive guide, but only once I've tested the end result, and perhaps given some more knowledgable members the chance to inspect the loom and see what they think of it.

[GLPoomobile 958]

Just thought I better add (just in case any of you are skim reading this. I know my replies get a bit lengthy!)........this isn't about solving existing faults with my car. I get the impression that some of the replies to this are because you know I've had some issues with my car. This is unrelated. I'm already repairing my existing loom. This topic is simply about me wanting to build a loom for the fun of it and to learn.

[jim205GTI 3]

Mmm i have often thought about doing this be interesting and i would learn!....... but lack of time gets me at the moment... i think i would probably just start with the sensor side of the loom then once i am happy with that working move on to doing the ecu side.....

 

Good luck with it......

[KRISKARRERA 2 1 Cars]

After all, bar the 405, the ecu stays in the cabin

Yes, some fool made that decision. Didn't they know it rains in the UK?!

I recently discovered VWPs catalogue. I remember way back popping into pug and asking if they sold replacement connectors and was told by some dunce that I'd have to buy a complete new loom.

[Grim.Badger 15]

Connectors add resistance to a curcuit most of the time so if you are bothering to do this I would do it properly and re-wire the ecu plug as well rather than splicing. Also just becuase the connectors have been protected and don't look coroded doesn't mean that they don't have a thin film or corrosion which again will increase resistance.

 

I recently tried to pull the pins out of an ECU plug and it can be done but you need to shove a thin screwdriver in the release a little plastic clip that holds them in place.

 

I'd like to see how you get on with this as it is on my to do list (but way down at the bottom).

[welshpug 1,657]

bar the 405, the ecu stays in the cabin,

 

zx, 306 xsara 406 all have engine bay mounted ECU's

 

Yes, some fool made that decision. Didn't they know it rains in the UK?!

I recently discovered VWPs catalogue. I remember way back popping into pug and asking if they sold replacement connectors and was told by some dunce that I'd have to buy a complete new loom.

 

lol, yeah that's the usual response, pug will actually sell you the connectors, but at about 5 times what VWP sell them for, and you'll still have to buy the terminals!

 

I'll be doing a similar thing soon, the ZX I've converted to 6 power isnt as tidy under the bonnet as I'd like, with quite a lot of excess wiring taped up to keep it out of the way, though due to reasonably good condition of the loom and the fact that its all colour coded and numbered to some extent I'll re-use as much as possible.

 

for myself the tools need I already have, and there are more out there that I might buy (you can get a tool to push the pins out of the connectors without damaging them from snap-on, and I'm sure Mac tools as well) and also with fixing/maintaining cars/truck being my trade now I'll use the tools quite regularly.

[pdd144c 0]

You'll need a pin removal tool and a special crimper for all the plug pins, so around £300 to get both. Connectors or crimps are fine if used correctly, better than solder as you won't end up with any of the potential issues associated with soldering. I’d recommend using adhesive heatshrink around any join to keep moisture out. It is also time consuming, quite often takes longer than expected! Good luck!

[Alastairh 47]

I'd make one more suggestion in addition to the comments already posted: Once the loom is made, consider obtaining a nice big wooden board and "pegging" your loom to it with nails at fixed reference points so that in future you can use the board to duplicate the loom quickly and without resorting to measuring the car again.

 

Yeah, we do this at my work when buillding new looms.

 

I appreciate what you are saying about the ECU plug, it's a fair point. I think the same can be said of any of the connections in the loom though - get a bad connection and you could be scratching your head when I doesn't work. I think you need to appreciate that this isn't planned to be some rush job, quick fix etc etc. I'll be taking my time, and doing things carefully, because I can afford to. It's a learning experience after all, not a urgently needed solution to a problem.

 

The thing about leaving the ECU plug alone, well the point is that I want to replace the whole lot, not do half a job. So if I left the plug alone I'd have to cut the wires and splice the new wiring to them. You wouldn't expect that if you bought a custom loom, and so it's not kind of solution I 'm after.

 

I'll probably put a wanted add up for an Mi loom soon, I'm getting eager to do this now. If I do get it sorted, I'll write a comprehensive guide, but only once I've tested the end result, and perhaps given some more knowledgable members the chance to inspect the loom and see what they think of it.

 

Fair enough. All i am saying is that from the people i know, plenty of people have had decent reliablity from looms that haven't had ecu plugs re wired, but well done crimping and soldering. Tends to be other things on these engines that break first.

 

Mean you wouldn't be going down all this route if your oil pressure wire had a decent crimp on it would you?

 

zx, 306 xsara 406 all have engine bay mounted ECU's

 

Yes, but i was talking about 1.9 Mi's And they get ice cream tubs to store them in.

 

Al

Edited November 28, 2007 by Alastairh

[GLPoomobile 958]

Mean you wouldn't be going down all this route if your oil pressure wire had a decent crimp on it would you?

 

Without meaning to sound confrontational, you're either not reading my posts or not understanding what I'm saying. OK, so my oil pressure problems from way back may have been the initial catalyst to this, but I'm not talking about building a whole new loom just because of that ! I'm already repairing my existing loom to fix the numerous issues I have. I now want to build an additional 'brand new' loom simply because it's something I'm interested in doing, i.e. for s*its and giggles. If I'm happy with the end result, I'll maybe get a few people to take a look at it and see what they think, see if I've f***ed up or could do anything differently etc, and then maybe I'll get around to fitting it on the car some time next year and use it until something goes wrong

 

Here's some smilies to show you I'm not having a go (but read my frickin posts )

 

EDIT: just re-read you post and realised I took that comment out of context, so it's ME who should read before posting. Ha ha ha, I'm such a f***ing monger

 

You'll need a pin removal tool and a special crimper for all the plug pins, so around £300 to get both.

£300? f*** me! IF it's that much then that's the idea dead in the water I've seen terminal removal tools in the VWP catalogue for about £20, and assumed I could make adequate crimps with the tools I have now, plus some additional ones for not much more money (I appreciate you get what you pay for). I haven't yet seen the ECU plug though, so if you are saying it can't be re-terminated with out these very expensive specialist tools then this is no longer viable as a fun learning experience

Edited November 28, 2007 by GLPoomobile

[pdd144c 0]

Pro Crimper Tool

 

Terminal Tool Kit

 

Really need the crimper to make the connections good or you'll have major problems... And some kind of removal tool unless you will be using new plugs for everything.

Edited November 28, 2007 by pdd144c

[GLPoomobile 958]

Pro Crimper Tool

 

Terminal Tool Kit

 

Really need the crimper to make the connections good or you'll have major problems... And some kind of removal tool unless you will be using new plugs for everything.

 

Top link doesn't work. Is there anything specific about the tool or is simply a much better quality version of a more general non insulated terminal ratchet crimping tool? As I said, I've not seen the plug so don;t know what the terminals look like, hence the question.