Bora crank but no start, no fuel or spark

[Siggers]

Hi Gents,

So I was having a noise from the front of my bora, put it up and found a loose bolt, fixed that, went to go take it for a test drive and it just turns over and over, at first I thought it was the fuel pump as it wasn't running at all, so I changed it out without luck.

But further inspection showed that it is working after I stop trying to crank and when I open the door.

The codes I am getting are

P0113 - intake air temp (had this since I bought it)

P1639 - TPS

P1337 - cam pos sensor

P1391 - cam pos sensor

The cam sensor errors I have had for a little while due to the chains being stretched I believe. However I have swapped them and changed them with no change.

Any help diagnosing the issue would be great.

I do get revs on the tacho after a second of cranking, also after long cranking it says STOP on the dash and low oil pressure, it's almost like it thinks it's running...

[Sirocco20348]

What noise were you experiencing to investigate it?
What bolt was loose?
When you say fixed, did you tighten it?
Is that all you did?

[Bora Sport]

Sounds to me like the timing is out. Maybe its jumped a tooth on the timing chain.

[Siggers]

It was a high pitched grinding/scratching. Yes I tightened it I could see where it was rubbing on the housing, the transfer/bevel case housing. I also took the passenger wheel off and cleaned it from the previous owner, it was caked in grease.

If the timing was out by a tooth it would have spark and fuel, not to mention run, even if it was terribly? I dunno exactly how the system works, but one would expect it to try to want to start...???

[Bora Sport]

In the older pre ecu cars like my mark 1 Golf I would agree. I'm no mechanic but I know with my wife's Jetta which has a toothed rubber timing belt, not a chain like the Bora, It was literally only out by a degree or two and that was enough for the cam position sensor to stop it from starting. There was a post on here recently by a guy with a Passat and he tried changing fuel pumps etc. because it wouldn't start after he changed the timing belt. I think it was more than a week of changing parts etc. before he took my advice to check the timing and that was what the problem was. Perhaps if the sensor doesn't pick up the signal the ecu won't allow a spark and fuel??

[Siggers]

I just read up on a few forums about other people having timing out and no start, seems they have spark and fuel, just no start, I don't have fuel or spark, I believe it to be either the computer or the Crank Angle Sensor, I feel like it would be the sensor, as the car seems to have gauges working, oil pressure warnings etc, which would assume that the computer is working?

[Siggers]

Does anyone have a ecu that I could try for diagnosing?

[beale187]

I might, but I'm in Syd. Got engine code?

[Siggers]

Covering the postage cost shouldn't d be a problem if no one else has one close by. BDE is the engine code. It's a 2.8 V6 if anyone wasn't sure.

[Mk1sleeper]

I'm no expert on Mk4's (except for starter problems arising from not doing up the earth strap on the top of the gearbox, after a clutch change NRMA told my wife the starter was toast!!)

But our Mk3 had the same no spark, no fuel problem, but only when hot, turned out to be the wire to the crank angle sensor was on it's way and enough to stuff the output from the sensor when it was hot.
Try the CAS first from memory it was only about 80 bucks.
Cheers, Scott.

[Siggers]

Thanks MK1 I have replaced the crank sensor with no change, also have unplugged both cam and the maf sensors to trick it to start. I am going back over the electrics tonight to see if I have missed anything.

[Siggers]

Another symptom is no check engine light at all... EPC light is always on.

[Bora Sport]

The other thing that it sounds like is the immobiliser.

[Siggers]

Mmmmm I did have a thought about that, however I have no idea how to check that Bora Sport.

I did some tests, ECU has no power to main pins I think 3 and 24, not sure what the other ones I checked were, relay 428 under the bonnet has no power they ground on the relay and with the ecu disconnected one of the main large pins has ground... I am unsure what's the go there, but applying ground power the the relays ground pin gets the relay to work, although it still wouldn't start, I had to stop as it started raining quite heavy, so that's as far as I got.

So questions, how do I check immobiliser?

How does the ECM get power? I read that the 428 relay is actually controlled by the ECM? How? How else does the ecu get power?

I also noticed last night that my passenger door won't lock or unlock with the key or the internal button, it had always worked, unsure if this is a symptom...

Just to recap, all fuses are getting power to both sides, fuel pump relay under kick panel appears to work...