3b s2 coupe resurrection

[andy10v]

I got the ECU to talk to VAG COM!



I tried doing output tests and the injectors dont click. N75, ISV etc all click away.

I had a quick flick through basic settings, TPS angle works and changes as you change the throttle, I tried cranking and RPM jumped to 120, then VAG COM lost connection?

Pulled fault codes and it has a ridiculous list of unknown errors, plus airbag, cylinder 7, and other things the car does not have.







(I have not uploaded the whole list, its much longer)

I do however have

00512 - Camshaft Position (Hall) Sensor not at reference mark

So need to;

Find out why injectors are not clicking, I guess see if they have 12v? Then check continuity to the ECU.

Check timing (again)

Find out why vag com connection was lost when cranking, is the ecu loosing power?

[andy10v]

Found pin 37 (+12v fuel pump relay) was pushed in on the ecu

Pressed it back in to place, but no difference.

[andy10v]

From S2central



K & L line have continuity from the ECU plug to the diagnostic plug in the fuse box.

[andy10v]

Starter refitted, earths checked, battery charged up, still just spins. Also tried a different fuel pump relay.

I have cut a multimeter lead and added a couple of metres of wire so I can check continuity from ecu plug to engine bay. Made a short wire with a crocodile clip on one end and a small spade on the other.

Current thoughts are

Check K & L line for continuity
Check ECU has +12v ignition on
Check ECU earths
Check ECU has +12v when cranking
Check fuel pump has +12v when cranking
Check for fuel when cranking
Check for spark when cranking

Then based on outcomes from that lot check hall sensor, flywheel sensors. Finally check most of the engine wiring loom for correct earths, +12v, continuity etc (but hope it does not come to that)

Any other suggestions?

[andy10v]

Popped the starter out again to check the timing pin, and its still there.

[andy10v]

Hello Andy,

You photos were blocked offshore, just got home and seen your progress.
You've got some awesome upgrades going on
How is it running now?

"Took pity on one of the wheels, brake dust is pish to get off"

No way!! I honestly thought you had anthracite wheels same as me

I have not been back near it, so still no start.

A4 has had a new radiator, heater hose, track rod ends, upper arm, balljoint boot and hand brake cable. (lying on your back in the rain is pish, then a seized pinch bolt and a snapped top mount bolt do not make the situation any better )

They do look good in anthracite, and it does not show up the brake dust half as bad.

[sjw185]

Hello Andy,

You photos were blocked offshore, just got home and seen your progress.
You've got some awesome upgrades going on
How is it running now?

"Took pity on one of the wheels, brake dust is pish to get off"

No way!! I honestly thought you had anthracite wheels same as me

[martinws]

Sometimes you just have to leave your car for a bit n do.some other stuff to cool off.

I had such a good time in the 90 with n75 unplugged last year.
Shame the a4 didn't last. I sat in a Westfield at Doune hillclimb and would have fitted with a slight adjustment to the bolted down seat.
New project? Second garage extension?

[newsh]

I need to get a gauge and the bits to plumb it in

[newsh]

You dont have some kind of choke in your return line? Or a beast of a fuel pump that flows more than the FPR can bypass?

Have you checked fuel pressure with a gauge?

No I havent

I only fitted a new FPR from the stealer.

[andy10v]

I'm still trying to work out why my car runs so rich, the injectors were bought as a matched set of 750cc but we had to set the injector value 850cc to get it to run. I keep wondering if it's something to do with 3B hardware but can't see how.

You dont have some kind of choke in your return line? Or a beast of a fuel pump that flows more than the FPR can bypass?

Have you checked fuel pressure with a gauge?

[andy10v]

When it was running was it good or poor idle and running rich?

Poor, had to hold it on the throttle, I did have major air leaks at that point though. I cant remember the AFR, it would be in cold start enrichment anyway.

[andy10v]

I think the fittings are a different size,I taped the feed to mark it.

[newsh]

I have not changed anything mechanically between in running and not running, hence I suspect some random electric component failure?

When it was running was it good or poor idle and running rich?

[newsh]

It's not possible to hook it up backwards is it? (except then you'd only have return line pressure I guess..)

I'm still trying to work out why my car runs so rich, the injectors were bought as a matched set of 750cc but we had to set the injector value 850cc to get it to run. I keep wondering if it's something to do with 3B hardware but can't see how.