annpspeirs Posted June 22, 2015 Share Posted June 22, 2015 Within 30 seconds of starting from cold the engine revs go from 800 to 1200 stay there for about 30-40 seconds then went back to normal. Yesterday it stayed revving for at least a minute, I blipped the throttle and it went back to normal. Any ideas please. Thanks Link to comment Share on other sites More sharing options...
euroserv Posted June 22, 2015 Share Posted June 22, 2015 Hello, I am guessing that this vehicle is a Euro4 from between 2007 and 2012? It's probably not much to worry about but i suspect that during starting the ECU is detecting a less than perfect battery condition, a poor earth or suspects a poor charge rate. The ECU is then raising the idle speed to add a little extra charge into the system, and restoring the normal idle speed when it is happy or if you intervene. It would be worth getting the battery and charging circuit tested to make sure and the earth strap between the chassis and the gearbox is prone to corrosion. You should treat this as an early warning and do a little investigating. Nick Link to comment Share on other sites More sharing options...
annpspeirs Posted June 27, 2015 Author Share Posted June 27, 2015 Thanks for your reply. Van is 2006 Fiat 2.3 Ducato. The battery was new January. I have a split charger from solar panels and those connections are OK. Do check charge rate usually every day. The fault repeated itself everyday until this last Monday when my alarm specialist exchanged a faulty control unit for another one. The fault with the engine has not returned, but the alarm siren doesn't seem to be working. I'm just wondering whether this has something to do with it. (Pie in the sky?) I will check the earthing if I can find it! Many thanks for your advice. The van is due to go back to Fiat tomorrow to check out this fault so I'll ask them to check out earthing. When having my shower tray sorted recently at Motorhome and Caravanning Solutions in Chard, he put his diagnostic computer on it as the fault occurred when it was in his charge and said it could be the field regulator in the alternator. I offered this to the Fiat agent who just glossed over it! Many thanks, Ann Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 27, 2015 Share Posted June 27, 2015 Ann, the problem you describe relates to the Fiat parts, not the conversion. You have two batteries, one habitation, which is where your solar panel and regulator most probably come in, and one starter battery, which, if the fault is battery related, will be the one to be checked. It is unclear which battery was replaced, or why. The charging rate to be checked is that from the vehcle alternator to the starter battery. Your alarm was, presumably, connected to the starter battery (as I believe most are), so the fault on the component that has been now replaced may have been the cause of the increase in revs, because it might have appeared to the vehicle electronics as a battery defect. If the alarm siren isn't working, but was before the work to the alrm was carried out, I would contact the alarm specialist again, and ask him to return to fix the siren. You will need to be very clear with the Fiat workshop over the issue of "earthing". This is the so called earth strap that allows electricity fed to the engine control electronics to flow back into the starter battery, so completing its circuits. The strap is between the engine/gearbox and the vehicle chassis, in the form of a broad, braided, strap. The currents involved in these circuits are very small, so any degree of corrosion at the two points the strap attaches can prevent them flowing, or cause them to them to take alternative, unintended, courses. This causes confusion in the electronics with unpredictable consequences. It is a known problem, and not uncommon. That is why Nick suggests getting this checked. My impression, from what I have read on the subject is, if in doubt over its condition (and if the rise in revs is still apparent), just tell the garage to replace it. It is not an expensive component, and it is not difficult to access with the vehicle on a hoist, so the cost for that should be quite modest. Link to comment Share on other sites More sharing options...
annpspeirs Posted June 27, 2015 Author Share Posted June 27, 2015 Hi Brian, Thanks for your explicit explanation. The engine battery 9 yrs old was replaced in January. The splitter regulator enables both the engine battery and the leisure battery to be charged from the solar panel and has been installed for the last three years and worked perfectly, until I discovered one wire to the engine battery had come adrift and as a consequence the engine battery went down whilst in storage. As I was about to go to Spain I decided to change the engine battery anyway because of extra cost abroad and made good the battery connections to the solar panel regulator. I have contacted the alarm specialist and he is going to replace the 6 month old siren he replaced in January. In your last paragraph I presume you are talking about replacing the earthing straps? As I've had a water ingress problem with missing n/s plug and missing screws in the scuttle, the lambar (?) sensor has already been replaced (as was an electrical connector now in a plastic bag in the fuse compartment). It was kept for me and there is slight sign of corrosion, but I wouldn't say it was that bad. However enough to show up on their diagnostic system. Many thanks hopefully the high revving has sorted itself, but will ask Fiat to look at the earthing connections on Monday. Ann Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 28, 2015 Share Posted June 28, 2015 Hello Ann. It seems the replaced item was probably a lambda sensor, which monitors the exhaust gas - basically to reduce exhaust smoke from over fuelling. It has to get hot to work properly, and they apparently age over time, so it is possible that was the cause, or contributed to it. It seems equally possible that a defective alarm component might have confused the battery state monitor into increasing the revs. Nick is the expert on these vehicles, and has previously proved more knowledgible than a number of the franchised Fiat workshops. He runs a hire fleet of Ducatos, and carries out most of the mechanical repairs etc in-house. My last para was indeed referring to the earthing straps (apologies - bit ambiguous, wasn't it? :-)), which I know from a number of Nick's previous posts are a source of various, difficult to diagnose, engine related problems. His usual advice is to replace the original with two straps of better quality. Full explanation in the first post in this link: http://tinyurl.com/nafpjbn If you want even more than that, just use the search facility at the top of the page. Leave the "Forum to search" as all forums, enter euroserv as author, eath strap as keywords, and set time to all posts. You'll then get bombarded with the history of this issue! :-D Link to comment Share on other sites More sharing options...
annpspeirs Posted June 30, 2015 Author Share Posted June 30, 2015 Brian, Many thanks. Did pick up on another topic about Nick at Euroserv. Fiat St Albans apparently have checked the earthing straps when it was in the last time. Today they have replaced the seal on No 4 injector because I told them it was leaking. No further charges. Can't check the high revving because it's not happening at the moment. Thank goodness. Seeing the alarm man tomorrow and hopefully can get that sorted too. Will look at the topic and mull it over. Thanks Ann Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.