colin weston Posted November 3, 2012 Share Posted November 3, 2012 My daughter has an Autosleeper Trident based on the VW Transporter. It is a 1994 (M Reg) fitted with the 2.4 litre diesel engine. It has some 55,000 miles on the clock. She has owned it for some months and apart from a few minor problems has been OK. However, last weekend it exhibited a problem starting from cold. The battery is new and the engine cranks over OK. The heater plug light, which I believe is wired into a coolant temperature sensor, illuminates but the engine fails to start when cranked. It will start using a tow start or a whiff of 'Cold Start' in the air intake. It runs perfectly OK once started and when switched off will restart readily whilst still fairly warm. It has been in a garage and they changed 3 of the heater plugs but this has not solved the problem. They have suggested taking it to a Diesel specialist who has suitable diagnostic equipment. I still feel that because of the way the problem suddenly appeared it is caused by something connected to the heater plug circuit. Question: Can the heater plug light illuminate without the heater plugs working? Question: Where are the heater plugs located? Question: How do I check heater plug operation with a multi-meter? Question: Is there a relay somewhere or a fuse that needs checking? Any suggestions would be gratefully received. Are you out there Clive Mott Gotobed? Link to comment Share on other sites More sharing options...
flicka Posted November 3, 2012 Share Posted November 3, 2012 Hi Colin Difficult to diagnose from distance, but IMHO it sounds a classic case of AIR getting into the system somewhere or pressure pump allowing fuel to "drain" back. Hence the "Tow start" or "Cold start" adds sufficient until the pump turning & delivering fuel. Worst case - Pressure pump beginning to fail, but that would also be apparent during engine running. Link to comment Share on other sites More sharing options...
thebishbus Posted November 3, 2012 Share Posted November 3, 2012 Hi. I do not know that engine, but glow plugs (heater plugs) are normally in the cylinder head, like small spark plugs. If you can find them, there should be 12 volts going to the top connection of them when the ignition is turned on with the engine cold. Brian B. Link to comment Share on other sites More sharing options...
colin weston Posted November 4, 2012 Author Share Posted November 4, 2012 Thanks for your comments. I went to my daughter's today to check out the glow plug operation. They are not easy to access so I thought I would check the glow plug fuse and the relay as suggested by someone on the Autosleeper Forum that my daughter had posted on. Unfortunately we dont have a handbook for the camper so I didn't know which fuse or relay in the fuse box to check. However, I pulled out each relay in turn and replaced it and made sure all the fuses were fully home. Operating the starter key to the glow plug heating position I could hear a relay operate. I then did a voltage check on the battery whilst heating the glow plugs and got a voltage drop of about 1 volt so the plugs were definately pulling some current! I then went through the starting procedure and the engine started!!!! I can only assume that either a fuse or one of the relays had a poor contact maybe due to vibration or corrosion, who knows. Wonder what the next problem will be? (lol) Link to comment Share on other sites More sharing options...
onecal Posted November 4, 2012 Share Posted November 4, 2012 Hi,You need to replace or exchange your heater plug relay ,as it can show heater light but no power,,,surly though who ever replaced the plugs should have checked this ,,,,for youRegards ,Brendan Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 4, 2012 Share Posted November 4, 2012 colin weston - 2012-11-04 4:46 PM ...Unfortunately we dont have a handbook for the camper so I didn't know which fuse or relay in the fuse box to check... VW T4 workshop manuals are available http://www.justkampers.com/shop/t4/accessories/workshop-manuals Link to comment Share on other sites More sharing options...
onecal Posted November 4, 2012 Share Posted November 4, 2012 Hi,,,Fuse board is at your right knee,,pull down cover and remove ,,,they are marked clearly as are the relays,,,,On the older T4 the main 50A fuse is in a black box in the engine compartment under windscreen ,,,This should have been checked by who ever replaced the heater plugs for you,,,You also need to check you battery and connections are in good condition as is the engine to chassis earth wireRegardsBrendan Link to comment Share on other sites More sharing options...
onecal Posted November 4, 2012 Share Posted November 4, 2012 Hi Colin Sorry,,,The heater relay has 102 marked in white on it's end ,,,,,replace it should help...check all wiring connection ,,pay special attention to the engine to body earth,,,connectionsRegards,Brendan Link to comment Share on other sites More sharing options...
colin weston Posted November 7, 2012 Author Share Posted November 7, 2012 Thanks for all the advice. Apart from one occasion 'Gerty', as she is called, has been starting satisfactorily from cold following the removal and refitting of the relays. I found the fusible link for the glow plug circuit under the bonnet and it looked OK. On 'Gerty' it is located on the inside of the RH wing. Over the years it appears that they changed its location more than once. I believe that the contacts inside the relay may have been the problem so decided to fit a new relay to be on the safe side. Went to VW dealer. Guess what a new relay costs from them? £90+ incl. VAT. Went to a local factor and got a Delphi equivalent (Made in Germany) for £40. Not yet fitted it but sure it will be OK. I am now a bit wiser. :-) Link to comment Share on other sites More sharing options...
onecal Posted November 7, 2012 Share Posted November 7, 2012 Hi Colin,,Should be ok for that model if The main 50 A fuse is where you say (RH wing ),,,,,Check the New relay when working as some replacements overheat due to poor connections with the board connections ,Regards Brendan Link to comment Share on other sites More sharing options...
George Collings Posted November 8, 2012 Share Posted November 8, 2012 Acccess to the T4 engine is tight but the whole radiator assembly is carried on short arms to allow it to be moved forward. The top crossmember has to be unbolted at each end and rubber locating plugs eased back down through the crossmember to allow the crossmember to come upwards. It makes the whole front face of the engine much easier to work on. I think the bloke who designed this was known as 'Big Hans'. Link to comment Share on other sites More sharing options...
George Collings Posted November 8, 2012 Share Posted November 8, 2012 Further to my earlier posting about moving the radiator forward. Pics. One is with the radiator in the normal position and the other was taken while the external body panels were removed to deal with rust in the radiator support frame. Here the rad has been pulled slightly upwards foreward and before dropping controlled by the two arms on each side. The glow plugs should show a low resistance something like 2 ohms or less from memory but they fail into open circuit . I had a similar problem with my T4 at around the 60,000 mile mark. Link to comment Share on other sites More sharing options...
George Collings Posted November 8, 2012 Share Posted November 8, 2012 Too fast on the send . now for the pics Link to comment Share on other sites More sharing options...
George Collings Posted November 8, 2012 Share Posted November 8, 2012 And the second Link to comment Share on other sites More sharing options...
colin weston Posted November 13, 2012 Author Share Posted November 13, 2012 Nice to hear from you again George. Hope you are keeping well. Thanks for the additional info. I will keep it for further reference hoping that I wont need it! Best regards, Colin Link to comment Share on other sites More sharing options...
George Collings Posted November 13, 2012 Share Posted November 13, 2012 Thanks Tony Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.