Just changed heater matrix now car will not start. Warning lights for check engine and temp are coming on. o

[pinki]

After years without cabin heat I got round to changing my heater matrix.
Disconnected the battery and removed dash. Changed matrix.
I connected everything up and turned the key but the engine will not catch, it sounds like the fuel pump is ok, and the starter is trying, but the engine will not catch.
After trying off and on for 15 mins, the check engine light, oil [the oil was low and i topped it up] and temperature light came on. I have disconnected the battery to see if it will help.
It was frosty last night and the car has not been started for 36 but i have not had a problem with damp before. All connections inside and in the engine appear to be ok except the seal around the coil pack is not properly sealing it. The rubber seal [like an O ring] is bulging out, so not doing its job properly, but i think it has been like that for ages.
Any help geatly appreciated.
Thanks
Pinki

[Alan02]

Can you check the voltage of the battery? The warning lights coming on could be an indication of low voltage. You should get 12.5volts fully charged. Anything that reads 11-11.5 v is no good. Also, have you checked around the fuse areas for loose relays/ connections or missing plugs since you re-fitted dash.

[pinki]

Battery sitting at 12.24V. Petrol light was coming after matrix change even though there is over 1/4 tank of petrol and dial shows this also.
I checked all relays under dash and seem firmly housed. All big fuses checked, just need to check small blade type

[green A8]

A bit of an odd one this. It sounds like you've not re-connected something properly during re-assembly. The only thing that I'd imagine could have been disturbed during the heater matrix change might be the immobiliser. I assume that you removed the instruments when you did the heater matrix job? I'd suggest checking the instrument connections, as from memory this is where the immobiliser lurks, on many B5's. Loose connections might also explain the other warning lights as the battery voltage seems to be ok. What year/model is the car?

[pinki]

The car is 1997 1.8 A4, late or crossover. I have checked the instrument cluster connections and all ok. I also checked behind the centre console and the connectors for hazzards and fogs etc are good, i had labelled these as per a walkthrough on a different forum. The things that are of concern are
1) a single wire coming out of the loom for the central switches. It is beige with a white stripe or vise versa. I cannot see where it goes and thought it may be from the original stereo or waiting for the addition of front fog lights which never happened.
2) On removing the steering wheel there were 2 connectors which needed uncoupled. though I am sure they were connected firmly and shouldn't have been niped,because they are below the wheel and a bit of a faff to check, these have not been double checked. I imagine they are horn and air bag deployment, could these give any more problems?

I thought I would check the throttle body to ensure it was not stuck and it moves though there appeared to be oil in the plastic air pipe which connects to the metal throttle body housing. The oil did not look like it it had gone through the valve door, but who knows.

Any more suggestions greatly received, as i will need to get it towed to a garage.

[pinki]

Well, I have lesrnt something new about my 17 year old car.
I have learnt what a flooded engine sounds like.
When the breakdoen truck came I thought it would be a tow to the garage, but he cranked the engine a bit attached his booster box snd cranked it a lot more. It eventually caught. when asked whst could cause that he said driving a short distance like 10m, which is exactly whst I did by moving it to a larger parking bay before working on the car. Good to know my work was not at fault ��

Anyway, sharing diagnosis and resolution in case it helps someone else. Thanks for the suggestions.