Skoda Felicia 1.3MPi Immobiliser fault?

[apd007]

All,

 

I have a Skoda Felicia 1.3 MPi that anyone who used to go to some of the old Weston Meets 15ish years ago might have seen (has it been that long???). Late last year the car did something she had never done before and let me down, to the point I had to be towed back home, luckily only 2 miles and a mate is a mechanic.

 

Initial symptoms on the drive home was a lack of power, to the point I had to pull over as there was no way I was going to make it up the hill near my house, the engine stopped running when I parked up. The lack of power, the engine stalling and coupled with the electric shock from the ignition coil housing when running diagnostics later, suggested the coil was breaking down internally, which as it's the original 20+ year old coil is to be expected.

 

I purchased a new ignition coil, and also a new crank sensor in case that was failing (also the original 20+ year old sensor) but the car still refuses to start. I'm 99% certain it's not fuel related as I've tried petrol down the throttle body and also easy start, the engine turns over, occasionally sounds like it's going to catch (or even does run for a second) but won't keep running. Forum searches have lead to the immobiliser failing, but I've not been able to find any codes to confirm or deny this. I've had another mate who is an ex-VAG master tech scan the car with his fully legit version of VAG-COM but couldn't find any codes stored of any description.

 

My mate who towed the car back and I even took the valve cover off and manually checked the valve timing in case the engine had somehow managed to jump a tooth, but everything was spot on.

 

I said to my mechanic when I swapped out the coil and crank sensor I wasn't willing to just "part cannon" the car and swapped bits out cause "it might be xyz" and he agrees (he thinks I'm crazy keeping the car on the road this long anyway).

 

The body work on the car is showing it's age in places, front wings are going as are the rear arches, although not MOT failure badly yet and certainly repairable for not a lot of money and was something I was considering having done this year. The bonnet has quite bad lacquer peel and the respray I did on the roof a few years back looks like it was done by the amateur I am. The bigger issue is I think the windscreen is starting to leak, and the sunroof leak I've never managed to fully solve either.

 

Good points are the radiator was replaced a couple of years ago, and last MOT I had the cross member radiator support replaced with a new piece of metal and also a small patch on the inner wing by the shock tower on the drivers side. Prior to the engine letting me down the car drove well. The car is a two owner from new, my sister first then me.

 

Sorry about the rambling post, and if you've made it this far, thank-you, it became a bit of a brain dump on where I am with the car and what my next move is. It's irrational how a piece of metal that was almost obsolete when new can generate such an emotional attachment.

 

So this is where I am, what do I do with the car? Do I risk another £90+ on a immo delete ECU and see if that cures it? Or, do I cut my losses and advertise it on here in the hope that someone is willing and able to take the car on and restore it, last thing I want to do is just scrap it as there aren't many left now and I feel the car has many more years left in it yet if I could just get the car to run.

[RicardoM]

I couldn't find in your description any proof that the issue is immobilizer related.

You have changed already parts without having clear evidence of what failed. I presume that you browsed this section for clues and tried what looked somehow related.

Since I don't know how technically savvy you are and what diagnose tools you own, let's start easy.

The first thing that I would check is the fuel pump. The second thing to check is some corrosion issue in a connector or inside the relay box, especially since you mentioned the windscreen is leaky.

So, do you hear the fuel pump whirring when you turn the ignition key on?

[apd007]

2 hours ago, RicardoM said:

I couldn't find in your description any proof that the issue is immobilizer related.

You have changed already parts without having clear evidence of what failed. I presume that you browsed this section for clues and tried what looked somehow related.

Since I don't know how technically savvy you are and what diagnose tools you own, let's start easy.

The first thing that I would check is the fuel pump. The second thing to check is some corrosion issue in a connector or inside the relay box, especially since you mentioned the windscreen is leaky.

So, do you hear the fuel pump whirring when you turn the ignition key on?

Hi RicardoM, thanks for the reply. I swapped out the coil because the car was lacking in power when it was running on its last drive, and then later when doing diagnostics I got shocks off the housing when checking to see if I had a spark - this lead to me thinking the coil internally was breaking down and arcing to the ignition coil body, so at that point I think you'll agree if the ignition coil is breaking down internally and producing a weak spark it makes sense to swap it out.

 

I do hear the fuel pump go, when I turn on the ignition. I have also put fuel down the throttle body and tried easy start, all to no avail.

 

I have had a look at the fuse box and relays and cleaned the contacts using proper electrical cleaner (sorry, should have mentioned that in the original post).

[apd007]

Just to add,  have also done a compression test on all 4 cylinders, 1 was a little low but the rest were fine.

[R_U_AFA]

I wouldn't have thought it is an immobilizer fault.

Did you try using original hall sensor with new coil pack.

[RicardoM]

Just to be clear, is it a crank no start issue? Or does it start for 2-3 seconds then stops?

As for the compression measurement, please tell me the values you got.

[apd007]

Hi, the car cranks over fine but won't run (or occasionally 1 second run).

I can't remember now the cylinder pressures, 3 were fine, and even the one that was low was over 110psi.

 

I'm not sure either if it's the immobiliser, hence my uncertainty.

[R_U_AFA]

You said you used easystart, did you have someone constantly spraying whilst cranking, or was it a quick spray into the throttle body then crank.

[apd007]

Spray whilst cranking.

[RicardoM]

According to you, the situation is as follows:

• fuel - checked
• air: checked
• timing: checked
• compression: checked

So we are left with spark diagnose. Check for strong spark on each cylinder with a spark tester.

If no spark, check the following:

• wiring from ECU to ignition coil and corrosion check in the 4-pin connector
• wiring from ECU to Hall sensor and corrosion check in the 3-pin connector
• wiring from ECU to knock sensor and corrosion check in the 2-pin connector
• presence of proper I/O signals at each pin of the above connectors with contact key ON and cranking ON.

By wiring check I mean continuity check and short circuit check.

[apd007]

🤔Knock sensor...hadn't thought of that, worth a look. When I get chance, probably the weekend now, I'll have a look and update.

[mikefelicia]

Hi apd007 I just to say keep with it mate you will regret it if you get rid of her, I have a 1998 1.3 Felly from new and there is no way I would swop it for a new car we have had our ups and downs but its still on the road after some 25 years.

 

I wont add to what has been said you have the best man on the job Ricardo (he knows it all big head) joking apart he's good.  

 

I will put in my bit the sun roof mine started to leak so now I clean it out and put some silicone grease only silicone in there it will help to keep the rubber good mine dos not leak now and man do we have some rain, regarding the screen leak you could claim on your insurance for a new screen maybe I did some 5 years ago but it has just started to leak a little now so I use my old favorite https://captaintolley.com/ it may or may not work. 

 

one day and I mean one day people will wake up and say hey these old Skoda Felicia's are one great car you know.

[Thefeliciahacker]

21 minutes ago, mikefelicia said:

Hi apd007 I just to say keep with it mate you will regret it if you get rid of her, I have a 1998 1.3 Felly from new and there is no way I would swop it for a new car we have had our ups and downs but its still on the road after some 25 years.

 

I wont add to what has been said you have the best man on the job Ricardo (he knows it all big head) joking apart he's good.  

 

I will put in my bit the sun roof mine started to leak so now I clean it out and put some silicone grease only silicone in there it will help to keep the rubber good mine dos not leak now and man do we have some rain, regarding the screen leak you could claim on your insurance for a new screen maybe I did some 5 years ago but it has just started to leak a little now so I use my old favorite https://captaintolley.com/ it may or may not work. 

 

one day and I mean one day people will wake up and say hey these old Skoda Felicia's are one great car you know.

Two questions my friend.
Is the vehicle rust free after so many years?
And secondly what about insurance I bet even with the slightest ding the IC would total it, and place a super high buy back price

[mikefelicia]

 

4 hours ago, Thefeliciahacker said:

Two questions my friend.
Is the vehicle rust free after so many years?
And secondly what about insurance I bet even with the slightest ding the IC would total it, and place a super high buy back price

What 25+ year old Skoda Felicia is rust free, it went through the MOT with no problems and has don most years no problems with insurance. This is the UK not Greece.

 

 

Edited 29 January by mikefelicia

[Thefeliciahacker]

49 minutes ago, mikefelicia said:

don most years no problems with insurance

I mean arent you afraid of using it?

[mikefelicia]

Grow up.

4 hours ago, Thefeliciahacker said:

I mean arent you afraid of using it?

grow up

[Thefeliciahacker]

55 minutes ago, mikefelicia said:

Grow up.

As I grow up so does the felicia, grows older and with older cars insurance companies become less willing to pay for them..

[D.FYLAKTOS]

18 hours ago, mikefelicia said:

no problems with insurance. This is the UK not Greece.

 

What's the annual price for a Felicia insurance in your area and what sections cover?

[RicardoM]

On 28/01/2024 at 21:28, apd007 said:

I'm not sure either if it's the immobiliser, hence my uncertainty.

A bad immobiliser would throw an error usually.

Moreover, the way your car started to act before failing is not consistent with an immobiliser fault.

Typically a faulty or not paired immobiliser results in the engine starting perfect but stopping abruptly in 2-3 seconds.

 

PS: please remember that I have no direct access to your car and I have to take your word for the diagnose of fuel, air, timing, and compression.

As an example in this regard, when I asked you if you can hear the fuel pump buzzing when key ON, that was the most basic check. That only tells current is getting to the pump. Yet that is not proof enough the pump develops enough pressure. You didn't mention how many miles your car has and when (it anytime) did you change the fuel pump. A fuel pump on its last leg can produce the exact symptoms you described. You would need a fuel pressure gauge to decide that.

[RicardoM]

20 hours ago, mikefelicia said:

What 25+ year old Skoda Felicia is rust free, it went through the MOT with no problems and has don most years no problems with insurance. This is the UK not Greece.

Mike sleeps with his Felicia in his bedroom. She has her own mattress. So no rust 😅

[apd007]

@mikefelicia, just curious but whereabouts in Brum are you? And regarding the insurance question, the car was written off about 10 years ago but I bought it back and got it repaired.

[apd007]

Quick update.

 

Disconnected the knock sensor this morning and tried to start, I'd expect a "limp home" mode if the ECU thought the sensor was dead, still no start.

 

Cleaned the electrical connectors under the bonnet, all seemed clean and well weather sealed, still no improvement. Spoke to my mechanic, he's going to speak to his auto electrician and get him to pop over and have a look.

[Bernardor]

Hi apd007 !

Did you start the engine?

[Bernardor]

On 30/1/2024 at 8:04, RicardoM said:

A faulty immobilizer would normally throw an error.

Additionally, the way your car started acting before failing is not consistent with an immobilizer failure.

Typically, a faulty or mismatched immobilizer causes the engine to start perfectly but stop abruptly within 2-3 seconds.

 

PS: Please remember that I do not have direct access to your car and must take your word for fuel, air, timing and compression diagnostics.

As an example in this regard, when I asked if I could hear the fuel pump humming when the key was turned ON, that was the most basic check. That only indicates that the current reaches the pump. However, that is not sufficient proof that the pump develops sufficient pressure. You didn't mention how many miles on your car and when (any time) you changed the fuel pump. A fuel pump on its last leg can produce the exact symptoms you described. You would need a fuel gauge to decide that.

What's an immovilizer ?

[D.FYLAKTOS]

5 hours ago, Bernardor said:

What's an immovilizer ?

 

https://rentingfinders.com/glosario/inmovilizador/

 

https://www.opinautos.com/do/skoda/felicia/temas/739411d899/inmovilizador