RW1

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.

Generally if there is a puff of oil smoke on start up from over night standing, the valve seals are more the suspect. If it blows smoke out on the overrun at higher revs (+4,000rpm), the rings are worn. The test isn't conclusive so also do a compression test as well. As said before, VR6s break rings quite often above 100k. I think with the plug going only in that cylinder, you have a broken piston ring. If the rings were generally badly worn then I would expect to see the other plugs to be similar. Best to do a compression test if you can. It should show No. 6 down on compression significantly. Obvioously with the engine apart, do the valve seals in the head as well, given the mileage the engine has done. Snetterton. You'll be lucky to survive as the engine stresses will accelerate the problem. Sorree to spoil the fun but..... a little now will not be a major later.

Dutch VR6, Vag-COM will show you the ECU part number. Yes a "461" is for the "AG" ECU and I'd expect your C to be an AG unit. The change is at the end of the 1993 - 1994 production run in July 1994, ie. as you say upto chassis 50RK015000 (Production actually finished at about 50RK007000). The last year of production chassis 50SK000001 onwards are the "462" for a "CP" ECU. I seem to remember the early one "461" is a hot wire MAF design, the later "462" is a hot film type.

Stock is:...... Fuel lines are hard plastic, black supply to engine, blue it the return to tank and clear/white is the tank to carbon canistor filter usually Runon the offside underside of the underside. I seem to remember seeing some on EBAY late last week (secondhand). Brake pipes are the usual metal and run down the nearside unside of the floor pan. Check the joints at the fuel filter, the next break in the lines is in the engine bay at the servo under the air intake ducting (unless not standard) between the MAF and the throttle body. This one does leak if it has been undone in the past and is fairly difficult to get decent purchase to tighten up cos of it's location.

Given what you’ve said about the flat battery, it is quite possible that the ECU has lost it’s settings at that point and depending how you drove it (or not!, as idle for the first ten minutes causes a lot of problems with rough running and stalling) afterwards. The ECU typically loses it's memory inside about 10 seconds, so if you cranked the engine with a flat battery for that length of time, the ECU 12 volt supply could have dipped below acceptable lower limit to maintain the memory. First you should establish that the ECU and all it’s sensor are OK, ie. there are no engine related faults otherwise the engine ECU can go into a reversionary mode to by-pass that fault in a few cases. If there are faults, note them and then clear them from the memory (NB 00513 engine sensor fault code will appear if the engine is not running but ignition on. This will clear on engine start if all is well.). Take the car for a short drive of about 15 minutes and take it upto and past where the hesitation occurs. Now re-interrogate the ECU. If any faults have reappeared, then these must be dealt with first. If there are no faults, then carry out the FULL engine ECU procedure in the knowledge based I have written starting with the ECU battery disconnection sequence if you want to drive it . It isn’t absolutely necessary to drive it that hard but it just quickens up the fine adjustments after 10 minutes have elasped. The first part can be just a drive with a couple of accelerations using a “held” accelerator pedal to make it constant for about 4 seconds, but do not idle the engine for the whole of the first ten minutes. The engine can idle during this 10 minute period for short periods of a minute such at lights. If fact, be sure to include at least one idle period of a minute and at least one overrun, throttle shut from 4,000 rpm to idle – 1,000 rpm range. Some parameters will take upto 30 minutes to establish but the ECU quick learn mode finishes after ten minutes for the VR6. After that only very fine adjustments are made to the factory dyno map offsets. After about an hour of running the engine, could be a few days later, perform the second part of the procedure using VAG-COM. Put the ECU and engine through the “Basic Settings” sequence. Follow the instructions set out in the procedure for the appropriate ECU. In your case, it’s Basic Settings on display group 001 in VAG-COM. Hopefully the hesitation will now clear.

Have you disconnected the battery at all just before this started? Will useful to know what the ECU fault memory has in it. Not convinced this is a MAF problem.

http://the-corrado.net/.archive/forum/viewtopic. ... hlight=maf :)

Not aware but I'm sure it will be copyrighted and protected by VW and VAG UK.

Jamie you beat me to it. But to add and dispell any rumours! October 1996 - Storm Badge Kit was £18.60 +VAT (£21.86). Part Number V853 VAG 819 Made in France at the 3M factory at Villebon sur Yvette. And here is what the kit looked like. 500 on the Corrado Storms (chucked on the seats at the docks in UK for the dealers to play with) and about 300 spares (285 in 1996 were noted on the VAG system). ------------ Hair dryer blown onto the badge at the bumper will soften the adhesive to allow it to begently coaxed off. Halfords double sided trim tape is good but don't wash the car for a week to allow the adhesive to air harden a little.

All Corrado ignition switches in the column have a "radio on" supply activated by pushing the key in and switching ignition on. This then sets the "Radio ON" but it doesn't switch off until the key is pulled out. ie. you can stop the engine and the ICE can still be powered as long as the key remains in the lock. THe wiring on the standard connectors works this way but I seem to remember you may have to swap a wire over (12 volt perminent / ignition "radio" 12 volts interchanged) as some ICE are not fully compliant with VW's wiring. Had to do this for Alpine at least. I'll dig the files out if you need them.

Having used 15w40 "high mileage" in one of my Rocco's, all three changes have behaved the same. Below 98'C ish it's fine but go above this and the oil pressure drops off for the same given engine speeds and outside air temps. eg. 15w40 Magnatec 2 bar at idle, 15w40 "High Mileage" 2 bar but go above 98mish and it dramatically drops to 1 bar and it's the same at higher rpm, 4 bar changes to 3 bar or even 2.5 bar. (The oil pump is new! And it was the same with the old one) Castrol RS is fine in a hot summer +25' to +30'C but it is like treacle down at 0' - 5'C so it's not a winter oil. Found it OK in summer but when Magnatec came out, that was very good and has the bonus of quietening the hydraulic tappets somewhat. Synta Silver from VW is just as good although it is a 10W40 oil and the older KR 16v engine would be better run on 15w40 grade summer and winter. 10w40 in winter if oil changing permits a synchronised cycle. Also found with "high mileage" that engine consumes oil, about 2,000 miles per pint (0.5 ltr). Not worth writing home about and the oil may have been design to do this given it's targetted for older high mileage engines but it's not on the plugs or throwing out the back. Magnatec doesn't do this.

An interesting one as 718 C's in September/October 1994 didn't have it fitted although the ECU is capable which means it could be retrofitted. And CP is the autobox engine combo ECU as well, electronically switched.

Coincidence I think.... as there is also "AG" with coil pack VR6 engines with that MAF "462" mainly 1993/94 models.

Cheers dr_mat. The calibration will be compensated through the lambda probe readings altering the 3 fixed point settings ("adapted values")and the active probe reading in "measuring blocks" display group 6.

Vw Corrado, 2.9VR6, 91-96 Vw Golf , 2.8VR6, 92-97 Vw Passat, 2.8VR6, 91-97 Vw Vento, 2.8VR6, 92-98 Which is the odd one out?? 2.9 C is a different ECU. The others have a common parent ECU part number. Check a bosch part equivalent list, sorree no address but google should find one. The sensor element could be the same but the casing will be designed for the 2.9 rather than 2.8 ltr engine. Not the fit in the duct but the airflow rate hence why the VW part number is different. Does any one know if the actual sensor bosch part number is the same? I've been curious for a while.

462's are ultra rare on EBAY. Only ever seen one at a trader's stall at a show (for £50). Dealer item at mega bucks. A lot of the EBAY items are diesels, so beaware. The engine will run on the throttle body position sensor but fuelling will be a little out until you fix it.

British summers +30'C tops, winters mostly -5' bottom (unless you're really "up north") => 15w40 Dr_mat, oil pump failures aren't a regular thing with the C so don't hang on this one. Just when some have gone surprisingly early. Not the pump design as that's fairly standard. Simple check if you have a gauge at 90'C oil temp 1.5 to 2 bar (23 - 30 psi) at idle, 3.5 to 4 bar (52 to 60 psi) at 3,000 rpm using 15w40 oil grade. Price? Job - quite straight forward, drop the sump - loads of little bolts, 2 bolts on pump, loads of oil around - little messy, less than an hour to do, one sump gasket besides the pump needed. Points to note, make sure the bottom face of the engine block is really clean so that the sump gasket sits perfectly otherwise seepage occurs and tighten the sump bolts from the C's centre line outwards so it doesn't "bow" in the middle and leak.

I'll stick with Kevin's line, summer running at idle 2bar, 4 bar at 2,000 rpm, even if it's only done 37K.

VW Fault Finding Programme No. 16/5 ( or Bentley page 91.55) Position 1 = Distance impulse number. (Can be: 3735, 6010, 3800, 6160, 3800, 6160 – depends on engine/mph or kph.). Position 2 = Country version code. (1 all except GB/USA, 3 = GB, 4 = USA). Position 3 = Speedo/Rev counter code. Position 4 = No. of cylinders (4 or 6). Position 5 = Display segment test. Position 6 = Impulse from speedo sender, 4 pulses per wheel revolution. Position 7 = RPM Display. Position 8 = Programme version. Applies to early VR6, later G60 & 2 ltr 16v’s.

So, please explain why have I seen so many Corrado oil pump failures due to wear over the years. When the owner is asked about the oil used... "I've always used 0w40 (or 5w40)?" And the pump failure seems more when using 0w40 Mobil 1. The failures are either the gears wearing or the pressure relief valve jamming due to rattling wear profiles forming. Mileages - 50k to 70k miles. The Corrado handbook and VW Corrado maintenance manual states 15W40 for ambient temps -10 to +30'C. 10w40 is -15 to +15'C.

PM me with your chassis number so I know which circuit diagram to look at. Testing can be done on the car.

Like Dr_matt says, fault code 00513 (engine speed sensor) is not suppressed on OBD1 VW's ie. all Corrados. Garage may have seen this and determined it's the sensor. They don't fail like this usually and I'd expect to see the engine cut out intermitently at speed as well before total failure. This may seem a bit odd but see if you can swap out the ECU Relay marked "109" part no. 357 906 381A if it is has a grey coloured cover, they tend to be unreliable due to poor quality control. Later ones have a black plastic body and are OK. It's located on the main relay/fuse panel.

Bob on! Jay, Straight from the Mk4 Workshop manual for a brake system with ABS..... "Only remove the sealing plugs on the replacement hydraulic unit when the corresponding brake pipe is going to be fitted." "If the sealing plugs are removed too early, brake fluid can escape (obvious!), it can then no longer be guarenteed that the unit is sufficiently filled or adequately bled." So, you need some sealing caps or similar for each pipe connection for the next scrap car donor. (Same applies for the original Corrado ABS valve block)

Not all Corrado give a visible/physical change, must be to do with sensor tolerances, you're not the first to have a Corrado to react like this! Even on cars that do change, it's nothing to write home about, its quite subtle. You should know! Typical stealers! They just abandon the customers when the going gets a little difficult than taking a spark plug out and emptying the oil. Most VW technicians just don't know, lack of proper training and every VW model being different, even variants of the same model. Corrado has 6 different set ups on post 1992 cars alone depending on the engine. So I suppose it ain't surprising when you multiply that number of differences by the number of models over the last 15 years. You have to be an anorak as the Basic Settings technicques are hidden away in the VAG manuals for each model. No, in the case of the Corrado OBD1, it puts the ECU into an offset mode to do the assessment of all it's sensor inputs. Oh, one last thing. Change any of the sensors, ECU temp, Throttle Position, Lambda Probe, MAF. Always do a Basic Settings afterwards with a fully warmed up engine (+12mins from start-up). As said before... somewhere, it's what makes the VR6 silky smooth to drive. Hmmm, thats a new one but I've not studied the 2005 models yet.

Also, check the cable linkage securing nuts on top of the gearbox have not become slack.