A2 Tdi 2003. Loss of power when cold ABS and Yellow Triangle on! All clears once engine is warm and drives normal. Very confused, please help.

[MoMo]

Hello friends
I'm forever grateful to you all for taking the time to read my post and request for help.

Audi A2 1.4 tdi 2003 model.

This suddenly started one cold morning a week ago and happens every time now.

Cold start and the yellow triangle warning light along with the ABS warning light including the red circle with the exclamation mark inside appear on the dash all together.

Engine runs very rough like it's choking. No power at all when I attempt to move the car in 1st gear and subsequent gears. Almost impossible to drive without getting honked from behind at traffic lights.

This will remain like this for 10 minutes or more and won't reset if I switch off the ignition and restart.

However, once the engine is warm and I switch off and on, all the lights disappear and I have full power again and drove from London to Lincoln and back. Next morning and every morning it's the same all over again.

I sincerely appreciate all your help and good health, peace and prosperity to you all.

Only the best wishes
Mo

 

[JHB]

It needs a scan. But I suspect the wiring loom to the injectors inside the rocker cover. This causes a misfire on 1 or more cylinders and gives you a dashboard full of warning lights. It is a relatively straightforward and cheap fix.

 

[CrispyEdd]

Injector loom is plausable indeed. Be good to know any work thats been done recently if any? Have you charged the battery up to eliminte this? Diesel filter maybe sludged up when cold and thinning out, when wa sit changed?
Scan will help us all fix it.

 

[MoMo]

It needs a scan. But I suspect the wiring loom to the injectors inside the rocker cover. This causes a misfire on 1 or more cylinders and gives you a dashboard full of warning lights. It is a relatively straightforward and cheap fix.

Firstly, I sincerely appreciate your reply and support.
I had a scan done today and it showed cylinder two misfiring and an electrical code about low voltage the mechanic didn't understand.
I will order a set of wiring loom to the injectors today and give it a try and let you know. Guessing it'll take a few days for parts to arrive.

Thank you again
Mo

 

[MoMo]

Injector loom is plausable indeed. Be good to know any work thats been done recently if any? Have you charged the battery up to eliminte this? Diesel filter maybe sludged up when cold and thinning out, when wa sit changed?
Scan will help us all fix it.

Thank you also sir for your super fast reply. I sincerely appreciate your support. I'm ordering a set of injector loom tonight.
I bought the car (impulse buy) 6 months ago (wanted one for 20 years) and it has been a pleasure to drive since especially after Timmus tuned it to 100hp back in July.
I have not had any work done at all since my ownership and a service is due now.
The battery hasn't shown any signs of weakness and I'm going to open up to check battery this weekend to see if it's an old or new battery.

I will see if I can get the diesel filter changed too.
I will be sure to get all of your recommendations done and report back here.

Thank you again
Best wishes
Mo

 

[MoMo]

Thank you also sir for your super fast reply. I sincerely appreciate your support. I'm ordering a set of injector loom tonight.
I bought the car (impulse buy) 6 months ago (wanted one for 20 years) and it has been a pleasure to drive since especially after Timmus tuned it to 100hp back in July.
I have not had any work done at all since my ownership and a service is due now.
The battery hasn't shown any signs of weakness and I'm going to open up to check battery this weekend to see if it's an old or new battery.

I will see if I can get the diesel filter changed too.
I will be sure to get all of your recommendations done and report back here.

Thank you again
Best wishes
Mo

Is this what it's supposed to look like? Or are there other bits I need too?
Thank you so much for your kind help and patience

 

[MoMo]

 

[A2Z]

Thank you also sir for your super fast reply. I sincerely appreciate your support. I'm ordering a set of injector loom tonight.
I bought the car (impulse buy) 6 months ago (wanted one for 20 years) and it has been a pleasure to drive since especially after Timmus tuned it to 100hp back in July.
I have not had any work done at all since my ownership and a service is due now.
The battery hasn't shown any signs of weakness and I'm going to open up to check battery this weekend to see if it's an old or new battery.

I will see if I can get the diesel filter changed too.
I will be sure to get all of your recommendations done and report back here.

Thank you again
Best wishes
Mo

Before you spend the 100 odd pounds on the injector loom it may well just be one of the connectors from the loom onto the injectors that has vibrated itself loose over the years as was the case with mine and meaning a simple tightening of the connectors fixes the problem (check them all) and zero parts to be purchased.
Only down side is the rocker cover needs to be removed to see.
Good luck

 

[MoMo]

That's great sir
I have actually found a set of injector loom for £35 should I just replace them anyway? The car has done 207000 miles

 

[Robin_Cox]

That's great sir
I have actually found a set of injector loom for £35 should I just replace them anyway? The car has done 207000 miles

Given that the rocker cover has to come off to fit the loom, it makes sense to buy an authentic one - Darkside have them for 70-odd pounds. You then also need to be aware that removing the rocker cover without warping it relies on undoing the bolts in the correct order and having some luck. You then need to refit the rocker with the bolts *in the correct order* or it will warp and it is likely you will need a new rocker cover with the appropriate model of seal because it is warped anyway - and these are now becoming difficult to get hold of.

 

[MoMo]

Thank you for your kind advice sir, In that case I will not attempt it myself and give it to the mechanic to take care of it.
Didn't realise a rocker cover was so easily warped, I've heard of cylinder heads warping because of the bolts were loosened or tightened in the incorrect sequence.
I'm very grateful for pointing this out to me and saving me a whole heap of headache

 

[CrispyEdd]

I'll see if I can dig out the pdf with sequencing on. The sealant you need is hymol blue and tends to go either side of the hump where the injector loom goes in and on the other end somewhere.worth doing back right corner too.
In jector loom resistance can be checked at the connections by taking the loom off the side of the head, being careful of pi k lock pin, the residence is 0.5 ohms I believe?!?

Personally I would leave the loom job "looming" and do the fuel filter, forst order the metal filter bleed from @depronman then attempt it....and do the service see hiw it is then.

 

[CrispyEdd]

Thank you for your kind advice sir, In that case I will not attempt it myself and give it to the mechanic to take care of it.
Didn't realise a rocker cover was so easily warped, I've heard of cylinder heads warping because of the bolts were loosened or tightened in the incorrect sequence.
I'm very grateful for pointing this out to me and saving me a whole heap of headache

 

[MoMo]

Thank you so much.
I feel so happy from this experience here on A2OC God bless you and everyone else here helping people.
I'm going to try all of the recommendations one by one and let everyone here know what solved the issue

 

[MoMo]

I'll see if I can dig out the pdf with sequencing on. The sealant you need is hymol blue and tends to go either side of the hump where the injector loom goes in and on the other end somewhere.worth doing back right corner too.
In jector loom resistance can be checked at the connections by taking the loom off the side of the head, being careful of pi k lock pin, the residence is 0.5 ohms I believe?!?

Personally I would leave the loom job "looming" and do the fuel filter, forst order the metal filter bleed from @depronman then attempt it....and do the service see hiw it is then.

I've never heard of a filter bleed before, am I to bleed the new filter before installation?

I'll try Googling it now

 

[depronman]

I've never heard of a filter bleed before, am I to bleed the new filter before installation?

I'll try Googling it now

The bleed screw is really a drain screw to allow water to be drained from the fuel system
The original plastic one is VERY fragile and is 95% certain to break
You have to remove it to change the fuel filter but you also should drain any water and a little fuel every 6 to 12 months

I manufacture cnc machines aluminium drain screws as a drop in replacement
PM me if you want one

Cheers. Paul


Sent from my iPhone using Tapatalk

 

[A2Z]

Indeed there is nothing yet saying it is the injector loom at all so I would definitely leave that job until last and try the fuel filter replacement first as recommended above.
When my problem arose it would happen randomly and not specifically when cold and would happen whilst driving occasionally even when up to temperature and then became slightly more frequent but it was just a case of turning the ignition off then back on again and it would reset, so it might not be the loom at all.
Sorry to have to say but just don't presume the mechanic will know what to do or indeed do it right as a lot are a bit rough and ready and don't have the finesse or care that many things on the A2 require.
Much better to ask advice from this forum if you have the luxury of time

 

[audifan]

Bad glow plugs also give these symptoms. Test each of them including their wiring. Cheaper to replace these than the injector loom. Weak / old / wrong capacity battery would soon complain with the first cold start of the day as the power from the battery is taken for the glow plugs and starter the voltage drop would be enough to trigger dash warning lights.

 

[MoMo]

Indeed there is nothing yet saying it is the injector loom at all so I would definitely leave that job until last and try the fuel filter replacement first as recommended above.
When my problem arose it would happen randomly and not specifically when cold and would happen whilst driving occasionally even when up to temperature and then became slightly more frequent but it was just a case of turning the ignition off then back on again and it would reset, so it might not be the loom at all.
Sorry to have to say but just don't presume the mechanic will know what to do or indeed do it right as a lot are a bit rough and ready and don't have the finesse or care that many things on the A2 require.
Much better to ask advice from this forum if you have the luxury of time

Thank you all so much. I really sincerely mean it.
I have never been on a forum of any sort before, given that I am a dinosaur when it comes to technology and at the age of 50 only just download WhatsApp 6 months ago . To scared to try or click on anything lol.

I will definitely try the fuel filter, glow plugs, loom and battery a step at a time to see what will eliminate the problem. I will of course let you all know here.
Oh, I have time I do, I've never rushed anything in my life .
I'm enjoying this, especially when I thought no one would bother with my cry for help.

I'm so happy and very grateful

 

[MoMo]

Bad glow plugs also give these symptoms. Test each of them including their wiring. Cheaper to replace these than the injector loom. Weak / old / wrong capacity battery would soon complain with the first cold start of the day as the power from the battery is taken for the glow plugs and starter the voltage drop would be enough to trigger dash warning lights.

Thank you so much sir, I will definitely try this also. First diesel so quite new to all the parts and techniques with regards to a diesel

Thank you for your advice