I hope some one here can help me please, I have been trying to find any info through the search option, but maybe I'm asking for the wrong topics? I can't find what I'm looking for and am desperate to get my wheels back on the road, my ability to work depends on it and I'm on a low budget, so I can use any help I can get please

 

So the problem is, a non running 6n2 1.4 16v estate from sept 2001, engine code AUA

the starter motor works, full working battery, alternator, sparks, plugs, fuel pump etc all work, she's been temperamental in wet weather due to the crankshaft sensor having corroded cables, which was only a problem in wet weather, once dry she'd run fine, LITTLE bit of varying revs in idle, but never let me down

 

Then 2 weeks ago, I got her started, reversed out of my space and she simply cut out, not to be started again, starter motor turns over but no sparks

 

So finally I got a new crankshaft sensor, thinking that was the problem, and which was easier to replace then anticipated lol, but still no luck, my car was parked up at this time half an hour away from me and getting there was tricky, so I managed to get the AA out yesterday who had a very thourough look and tested all sorts and he suspects its the ECU, now I know due to its position under the window wiper arm its very possible its water damaged and I am looking at replacing it, which will be my first question, having done a lot of googling, I am led to believe that if I have a 'virginised' preowned one, I can just plug it in and it will sort itself, does anyone on here know if that's correct? Or will it need remapping? 

 

My second question is, before I spend more money on parts that aren't the cause, could it be anything else then the ECU? I've read many posts over the last 10yrs of owning 3 different Polos, and am aware that there are several faults that could cause similar symptoms, I'd just like some advice of you knowing peeps, do you have any experience with this and please can you help? 

 

With kind regards, Vivian 

Ps I really really don't want to give up on this car, I bought her as a project, according to the dvla there are only 25 of this engine and years type still on english roads, with mine being the estate version she is possibly one of kind left, my dream would be to get her up to show standards eventually, but I'm only a self thought home mechanic single mum, so any serious advice is very very welcome ( I'm also extremely stubborn lol, so telling me to give up is no use 😜) 

Done a lot of reading and read on a few places about the breather pipe, so I gave it a quick check and it's filled with mayo! I will investigate later, but could this be my nin starying problem? 😊 

Its a new problem by the way, my old pipe broke a few months ago and I put this one on myself so I know it was clean 

Edited 22 February, 20197 yr by Schnooky
Add picture

In cold weather, it is quite normal to get 'mayo' building up, especially if the car is used mainly on short runs.

This stuff is made up of emulsified oil, the water content of which is simply down to condensation inside the engine.

Your photographs show minimal amounts - If you remove the oil filler cap and find tons of the stuff, that may be a different matter, but even then, I doubt that it would prevent your engine from starting.

 

In attempting to answer your second question, the answer would be 'yes', it could be things other than the ECU that are preventing the car from starting BUT, the AA generally do a good job of fault diagnosis, and as you say that this chap had a very thorough check around, I would have thought that he would have found an alternative problem, if there was one.

 

It may well be cheaper to have your existing ECU tested, and if required, repaired. If you search for something like 'Automotive ECU Repairers (UK)', you will find people who will undertake this work - Be sure to put the 'UK' in though, or you might find that you are dealing with someone overseas.

 

A alternative might be to have a local Auto Electrician take a look at it for you, but of course, you would have to pay for their services. - If you do take this rout, try and find someone who is recommended.

 

Regards

Thank you Caretakerplus! Yeah after reading up some more on the mayo I learned what it is and that its quite normal, I was secretly hoping for something more simple, and of course cheaper, then the ecu, haven't had a chance yet today to do some more investigating on the car, but will have a Google on ecu repairs, thank you for that, can I take it out safely without disturbing anything? So just in case its not broken I can just plug it back in?

😊 

It takes a lot to kill the ECU's and they are pretty well insulated against water ingress, so unless the area under the scuttle panel was completely flooded I doubt it has suffered internal damage from moisture, I would take a good close look at the three connectors down by the thermostat housing as those are a know area of trouble, with the wires corroding off the contacts, also the coil pack itself, the pins between the removable amplifier and the main body of the coil pack can suffer from corrosion.  

 

TBH, I wouldn't take too much notice of the AA guy, if they can't find an obvious item, they tend to pick the most expensive item and say that's the fault !  

 

You can safely unplug the ECU if you wanted to send it away for testing, the only thing you would need to worry about on refitting it would be the need to do the throttle body alignment procedure and possibly the EGR setup with VCDS

Thank you again Nige! Was hoping you'd come with some hope bringing advice 😍 I'll get on the case and check those points, I'll be back with an update 😊👍

Having spoken to my partner who was with the aa guy all the time, according to the aa there seems to be an intermittent power between the ecu and the fuel pump, so I'm going to get in there to check the wiring, had a quick go yesterday, but couldn't find anything wrong with the thermostat housing pins, wish me luck! 

Oh and the egr valve is plated off, so that one is off the list to check 😊

The ECU switches an earth signal to the fuel pump relay from pin 65 of the ECU (Grey/Blue wire) and that goes direct to the relay, the power for the relay coil is from fuse #26 via the airbag crash relay and the actual power for the fuel pump is via fuse #2 (50 amp) on the battery box.

 

The fuel pump relay also supplies power to the injectors the  lambda sensors and the carbon canister valve, the power to the coil pack is via the ignition switch via fuse #34 (10amp)

Well after some thinking, I recalled reading something somewhere abour the elec windows and central locking, and my offside door has been having trouble ie not working, so I took off the door panel and as I was messing with the cables in there, with the key on contact, the relay box started ticking again, so I removed all relative fuses, windows and locking, and low and behold, the fuelpump instantly started zooming again and she starts!! It looks like there is corrosion on cables on the inside of the car, where they go out to the door, I'll add a picture, but at least I know its deffo not the ecu! She's still running a little rough and rev counter not working with oil light coming up, but I know that's down to the crank shaft sensor I replaced, its possibly not the right one, but at least she starts! Sorry to say, but damn I'm good lol! Love a good challenge, probably why I drive a Polo 😂😂😉

 

Many thanks for your help Nige, hope this info might help you too one day 😊

Edited 24 February, 20197 yr by Schnooky
Edited for spellings

I can see the green crud in your picture, which obviously needs investigating/cleaning.

 

A common problem with doors (particularly the drivers door) is that, due to constant flexing when the door is opened/closed, wires inside the rubber convoluted sleeve between the body and the door, tend to 'work harden' and eventually break.

 

I'm not really sure why working inside your door should make the fuel pump start though, but at least you know what area you were working in when the pump started.

 

A word of caution when working inside doors - Keep your fingers away from the window winding mechanism, once these things start to move under power, they don't stop! even when they have your fingers in their grip.

 

Another fairly common problem on your model, is the 'plate' fuses. In appearance, they look as if they might just be connecting links, but are in fact, fuses.

The problem with these is that they tend to crack, the crack being invisible with the fuse in place, but when the fuse is removed, it breaks in half along the crack.

 

I'm glad that you have sorted the problem, it just goes to show what a little determination can do.

 

Regards.

6 hours ago, caretakerplus said:

I'm not really sure why working inside your door should make the fuel pump start though, but at least you know what area you were working in when the pump started..

It's a VW feature. Open the driver's door and the lift pump runs and primes the high pressure circuit, so there's less delay when starting.

 

9 hours ago, caretakerplus said:

I can see the green crud in your picture, which obviously needs investigating/cleaning.

 

A common problem with doors (particularly the drivers door) is that, due to constant flexing when the door is opened/closed, wires inside the rubber convoluted sleeve between the body and the door, tend to 'work harden' and eventually break.

 

I'm not really sure why working inside your door should make the fuel pump start though, but at least you know what area you were working in when the pump started.

 

A word of caution when working inside doors - Keep your fingers away from the window winding mechanism, once these things start to move under power, they don't stop! even when they have your fingers in their grip.

 

Another fairly common problem on your model, is the 'plate' fuses. In appearance, they look as if they might just be connecting links, but are in fact, fuses.

The problem with these is that they tend to crack, the crack being invisible with the fuse in place, but when the fuse is removed, it breaks in half along the crack.

 

I'm glad that you have sorted the problem, it just goes to show what a little determination can do.

 

Regards.

 

Well, I still don't know what I did and maybe it was just coincidence, but when I plug the fuses for window and central locking back in, I get the same problem, I haven't had a chance yet to sort the cables, so simply leaving the fuses out for now, when I bought the car, the passenger window was being help up inside the door with a piece of wood.... 😎 🤭 Yep, not even a frame to hold it in, so that one has never been a problem, I altered it a bit so it can at least drop down about 3 inches, but the driver's side does have said frame, I already replaced the motor for it, but that one stopped working, hence I knew there was a problem in there, what I didn't realise was that there is quite a bit of water inside the door, maybe that's where the shortcut came from and caused the problem? but again, the window is only held up with some pegs, not connected and not even on the frame as I need to be able to open it all the way weather permitting, and whilst working on it before this problem I already found out to keep my fingers away lol 😁 it's really difficult to find either frame or other estate specific parts, unless I'm willing to fork out half of what I bought her for, simply not possible on my budget right now 😔 prioritie is to keep her running 😊

 

I wasn't aware about the plate fuses, and as I'm still learning, I'll have a look into them, thanks for that, and yes, it's just so satisfying when I can get things like this done, makes me feel well proud

 

It's also another reason I've rejected offers of other cheap runners to replace her, I'd have to start all over, at least with this one I know what's wrong and what I already done to her 😊

I also checked on the crank shaft sensor, took it out again and repositioned it back in, which sorted the rev counter and oil light, her idle is much more stable now, still a little rough here and there, but will tighten the bolt a little more after a couple of drives which I think will be needed as I was too worried to round it, but there was still a tiny bit of room for tightening it, I'll update again, for now at least she's driving 😊

 

next problem, front springs, apparently there's about 7 or 8 different types and as I replaced struds with springs from the breakers yard, I don't know which ones are the original ones and which ones to go for yet, though I think it'll simply be easier to do the struds again 😊

This what the fuses look like when they have completely broken 

 

This will give you an idea what struts should be fitted https://volkswagen.7zap.com/en/rdw/polo+classic+variant/poc/1998-241/4/  and remember your car shares most parts with the Seat Cordoba

Ha! about 16-17 yrs ago I was driving a seat cordoba, and it had very similar problems too, I loved that car but my ex decided to get rid of it as he couldn't be asked to get it fixed, so got a chrysler voyager instead.... 😂😂 That was before my days as a homemade mechanic though, otherwise I would have probably fixed it myself 😁

 

But yes, I do know, there's also several Skoda parts that fit my car, like the alternator I put in her 😊

 

I already found that site on one of the threads on here and had a look, but I seem yo have to find out the colour code on the ones that are on my car, but as I said, those aren't the original ones either, I've been concentrating on getting her driving again though, and will have a closer look at that site, it's really good and very helpful in finding part numbers 👍

 

Where would I find those flat fuses on my car though? I can't recall having seen them 

Those fuses are on top of the battery 

 

This gives a description of the springs (sport/heavy duty etc) for the different engine codes https://volkswagen.7zap.com/en/rdw/polo+classic+variant/poc/2000-236/4/407-407011/#26

Thats what I thought about where the fuses are, thanks 😊 

I'll go have a dig for them springs, thanks for all the help, I am proud to have been a member here for nearly 10 years now, I couldn't have done it without all the help and tips I got from here 👍♥️

THANK YOU to the person who sent me the schematics of my Polo! 😍😘👍 I got them in the post yesterday, it'll be of great help! Thank you so much 😊 xx

I thought they might be useful 👍

Just reading about the Crankshaft sensor i think i may have the same problem on my 6n2 1.4 mpi AKP ENGINE.

?Where did you purchase the sensor from.