Weird VR Cutting out - sorted (so far), 31.5.05

[fla 9]

As per the heading, whilst accelerating (2000 rpm) the engine cut out briefly and then restarted. It did this a few times before the 1 mile trip home. It was similar to the cutout sometimes faced when pulling up to a junction which is usually attributable to the ISV being dirty or the throttle body being a bit mucky. I've recently cleaned out the ISV, which wasnt too bad, although didnt do the TB. The strange thing about these cuttings out is the fact that I was accelerating, albeit not too much as the engine had to warm up. Ideas chaps?

 

TIA

[vr6storm 0]

get it on VAG-COM if you can to rule out those pesky sensors :twisted: ..........could also be the fuel pump on its way out.......mine used to do the cutting out at junctions once in a blue moon(but easily 2/3 times a year )prior to getting a new fuel pump over a year ago and touch wood.........not done it since

[fla 9]

Sorry (VR6storm), forgot to mention I already VAGCOM'd it and no errors (at the moment!)

[vr6storm 0]

Sorry (VR6storm), forgot to mention I already VAGCOM'd it and no errors (at the moment!)

 

 

check fuses and relays to see if they are loose :wink:

[K-rado 0]

Sounds to me like a classic fuel prob. It has happened to my old C and my current C after i filled up with standard unleaded. If the vag-com is showing no faults, then the sencors should be working fine. the sencors read the fuel mix and adjusts the ecu every now and again, causing it ti cut-out. re-set the ecu, and run a couple of tanks of Super. the VR seems to prefer 98RON (not optimax). Sorted mine out a treat and no probs for the past 6kmls. good luck :wink:

[fla 9]

Thanks chaps, will check both fuses & relays and will reset the ecu again.

[fla 9]

BTW, apart from the fuse and relay panel on the RHS of the dash, is there anywhere else he relays may be or is that it? How can I check the operation of the relays?

[fla 9]

OK, checkked the relays under the dash, all appeared slightly warm (ie functioning) but it cut out again as I pulled in to the company car park. There was a slightly rumbly area I drove over after which it cut out which again suggested a loose connection somewhere - problem is where the hell is it and how best to try an locate it? This is getting bloody frustrating and makes me wonder about keeping the car :mad:

[fla 9]

Absolutely crapped myself on the roundabout as it just died and took a while to start. Plus coming down the motorway the revs kept fluttering between about 3kk and 2.5k as the engine tried to trip out. I was a bit nervous about taking my foot off the gas coming to a roundabout but surprisingly got back ok. VAG COM codes as below:

 

00518 - Throttle Position Sensor (G69)

16-10 - Signal Outside Specifications - Intermittent

00638 - Engine/Transmission Electrical Connection 2

03-10 - No Signal - Intermittent

00300 - Transmission Fluid Temp. Sensor (G93)

34-10 - No Elaboration Available - Intermittent

 

TPS has recently been replaced (Mr Haywire thanks).

 

Any input would be appreciated.

 

TIA guys. Electrical problems are the worst for me as I dont have much of a clue about them.

[Henny 0]

From a non-VR6 owning point of view (and from someone who really has almost no experience of VR6s) that looks horribly like a dodgy earth/connection somewhere to me... :|

 

Throttle, transmission and fluid temps all reporting intermittent would make me think about checking all the multi-plugs for green contacts/cracked/ill fitting wiring connections where the connections for these sensors are breaking down.... :| Especially that BIG connector on the side of the engine I've seen pictured before... ;)

 

Of course, not owning/having owned a VR, I could be barking up the complete wrong tree.... :roll: :oops:

[Flo 0]

Check the main engine harness at the top of the N/S of the engine. Had some similar problems myself when 2 of the wires chaffed their plastic shielding off, allowing them to touch and short out. We diagnosed it by having the engine on and wiggling all the wires we could find in the engine bay until it started misfiring!

Give that a go.

[Kevin Bacon 5]

Yes Fla, Flo and Henny have suggested some good pointers there.

 

LOL, Flo and Fla.... Bill and Ben, Kev and Bev... :D

 

I reckon the "electrical connection" error (very ambigious!) is causing the cutting out. I've driven my VR with the TPS disconnected and it used the MAF for fuelling. It drove like a stale bag of shid, but it didn't cut out.

 

That TPS I gave you should be OK as it worked fine on mine....hmmm...hopefully we'll get this sorted ASAP for you, and maybe answer one or two things for other people too.

 

EDIT- Why has the forum suddenly started underlining some abbreviations and turning them red??

[Henny 0]

kevhaywire, Andi's added a new feature to the forum... hold your mouse over the red writing... ;) 8)

[Kevin Bacon 5]

Ah right, nice one! Well done Andi.....

[fla 9]

Will give it a go this weekend. I'll take off as many connectors as poss and clean them up and see what happens. Will hopefully have something good to report back.

 

BTW, i think the red text and underlining (which links to a definition) is quite a good thing, especially for noobs, to understand some of the technical chit chat.

[Kevin Bacon 5]

Just a test.... ECU, ISV, MAF, ABS, TPS, VAG

 

Hmm...need some more definitions I think!

[Henny 0]

*cough* add some then *cough* ;) :lol:

[fla 9]

OK i took it for a drive just now, ran beautifully, came back, popped the bonnet open, cleanned all the connectors I could see (could actullay get that big beefy one off) and then fiddled with the connectors and wiring to try and get it to cut out. I'm glad it didnt but concerned that I havent found the fault, especially with all the fault codes listed earlier. I'll reset the codes and have another try later as its too bloody cold now. Anything else worth looking for?

[fla 9]

could actullay get that big beefy one off

amend that to COULDNT.

Cut out again as I came up to a junction, but hopefully, that will be because I havent yet cleaned the TB. If after cleaning that out I still have the same prob what else is worth checking?

[fla 9]

Oh BTW, is there any way of checking the TPS separately?

[Kevin Bacon 5]

If you've got VAG-COM, plug it in, turn the ignition on, load up the engine page, go to 'Measuring blocks', Click 'up' 3 times to load measuring block 003, slowly press the throttle down and make sure the throttle angle moves up to 90 degrees (full whack) smoothly. If it jumps or skips a large amount of degrees during it's travel, the TPS is worn out (hope it isn't or I'll owe you a tenner!)

 

RE: The large round connector - you have to twist the lock ring through 90 degrees and then withdraw. Should come off really easily, if not someone's had a play in the past.

[fla 9]

Wil have a go, cheers for that Kev. Anything else I should have a look at for this issue?

[fla 9]

Just a bit of feedback here chaps - after having the car diagnosed manually (ie sensors checked with meters rather than just VAGCOM) it turned out that the Crank position sensor was not operating at its best. Took it out, cleaned it, magnet seemed quite strong, but the engine block was quite rusty where it attaches to teh block. Gave it a good ol' clean with emery and a spray with WD40 and so far there's been no problem. Yet....

Anyways, upshot is if you do have this problem, check teh Crank sensor but also check the block for a clean conductive surface. If not give it a clean until its nice and shiny. And remember to clean all that crud off, and dont let it go in the engine! I'll report back if there are any other problems.

[fla 9]

I knew it - this one was short lived. At idle (stuck in traffic) it died and took a 5 minute wait to get restarted, much to the annoyance of the cars behind. Same thing again about 3 miles down the road. The auto electrician came and checked the electrics and as luck would have it there was no problem he could find (as is always the case!), nor did it cut out at all, so he wasnt able to diagnose anything. I thought that cutting out at idle would be related to the ISV being gunged up, but thats clean and moves very freely. The Crank sensor is also clean (as per my previous post) so I'm at a bit of a loss now - not really sure what to check now. All the fuses look ok, relays seems fine, nothings loose, it just dies if it wants to at idle and takes a while to start. Oil temp was about 96 at the time, so there should be no issue with heat soak. Bloody annoying, as its fantastic otherwise.

[RW1 0]

Fla,

 

The nature of this fault isn't the MAF or TPS or a cleaned ISV. I'd take a look at these as the cut out is too abrupt for the above. Cos not sure which year your VR6 is, here are some points to consider......

 

On the VR6, the ECU relay has become troublesome like the stalling / starting problems/cut outs you describe. If the cover is grey plastic, these are the ones that appear to have a manufacturing quality problem leading to open circuit on the relay mounting board internally. The relay to investigate / possibly replaced is marked 109 on top part no. 357 906 381A Grey coloured cover. Later ones are black plastic covers and don’t seem to suffer. No easy way of checking off the car, borrow a unit to try.

 

Secondly, does the alarm immobilse the ECU in someway? If so, can this be bypassed? It may just be playing up (electronics or loose connection) and randomly inhibiting the circuit.

 

Thirdly, it could be a engine speed sensor and fault code DTC00513. As a quirk of the ODB1 diagnostics you need to catch this fault by interrogating straight after the engine stops WITHOUT switching off the ignition. If the ignition is switched off and back on, then as we know 00513 appears but as soon as the engine is restarted, the fault unlike the other fault codes is wiped from the memory.

 

Engine speed sensors seem in quite a few cases I've come across fail intermittently at all sorts of engine rpms and only later become a hard fault. Given the cost of a new sensor, you need to catch it with diagnostics as above or borrow a spare to verify.