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| Car won't start, help very much appreciated. - FIXED, NOW WITH FULL WRITE-UP | |
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| Tweet Topic Started: Fri Mar 23, 2012 6:36 pm (1,717 Views) | |
| WillTepper | Fri Mar 23, 2012 6:36 pm Post #1 |
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Newbie
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Probably best to go from the beginning... I've had the car for about 2 months now and it's been great. It has always had a slightly rough idle (low compression on cyl. 2, mechanic said it might be a hydraulic tappet but runs fine when revved and I can live with a shaky idle). Sometimes it hunts between 500-1,500 rpm at idle, not very often but it's probably the idle air control device, which I cleaned today. Anyway, a few days ago I ran out of petrol, we put some more fuel in and the car was fine after that. But yesterday, after an evening of driving, the car refused to start. Letting it cool down didn't change things. The RAC man turned up and checked the fuel flow through the pump/filter, which he said was fine. He also checked the ignition with an inline test light and didnt find any problems there. He eventually managed to get it started with some easy start straight into the air metering plate (if that's what it's called ) and giving it some throttle. It ran, but you needed to keep the revs up otherwise it would die, but after a while it settled down and would just about idle, and I drove it home like that.So I went out this morning and it fired, but wouldn't run. It did that a few times, then wouldn't fire at all. I eventually managed to start it with the throttle open and it ran, but backfired a few times and wouldn't idle. Thus far I have removed and cleaned the contacts of both the OVP and the ECU, which I also tried to check for dry joints, although the OVP didn't want to come apart so I left that (the fuse was fine). No joy. So I bridged the terminals on the socket for the OVP as suggested in a workshop manual. No difference. I then put the OVP back. I don't think there's anything wrong with the fuel pump relay because you can hear the fuel pump running. I've been aware of this forum since I've had the car and found it really helpful so far, but I've only just got around to joining. Any light you guys can shed on the matter would be hugely appreciated. Have a picture for reading all this... ![]() Thanks in advance! Will |
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| JustbeCoz | Fri Mar 23, 2012 8:11 pm Post #2 |
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check inside of distributor cap and rotor for moisture and tracking or arcing.rac man would normally do this.also check non-resistor plugs are fitted as incorrect plugs are thought to damage ignition modules |
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| mexicopaul | Fri Mar 23, 2012 8:33 pm Post #3 |
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Hi Will, check that all pipes are connected to the idle control valve (the pipe coming out of the bottom of the manifold as well can blow off). After that i would go for the OVP relay. Paul |
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| stwat | Fri Mar 23, 2012 11:48 pm Post #4 |
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Also check the rubber boot below the AFM plate and all rubber pipes attached. |
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| cosser | Sat Mar 24, 2012 11:23 pm Post #5 |
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The Idle hunting is usually a symptom of an air leak in the vacuum system..check the vacuum pipes for any splits..they usually go near to the ends where they're connected at various points..have you got a spare OVP you can try to eliminate it as the cause of the non starting..otherwise get it opened so you can check for dry joints..!!I think there's two types..one has a casing that is pinched and the other has two lugs which are bent over at the bottom..they can both be opened up with a little patience and repaired. Cosser..!! |
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| WillTepper | Sun Mar 25, 2012 7:54 pm Post #6 |
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First off can I just say thanks so much for your replies, especially considering it was my second post on here. Second... you guys were right, 10/10 for a quick and accurate diagnosis. Today's progress: I took off the fuel lines, fuel metering head, air metering assembly and the idle air control valve, i.e. most of the injection system. The rubber housing that joins the air metering assy. to the throttle body is seriously deteriorated, and the hose that joins the IACV and this rubber thing has been heavily bodged in the past. Hopefully that's our problem! Any ideas as to where to get replacement hoses & the rubber housing anyone? I've checked the dizzy over and ordered some non-resistor plugs for it, not sure what's in there at the moment but it was only £5 for a set so I figured I might as well. Cosser I've got the OVP with 2 lugs on it, I've bent them back and the plastic bit with the pins in it will come out of the metal housing a bit, but doesn't seem to want to come out. Is it just force needed? Is there anywhere in particular that's good for replacement OVP's other than the 'bay? Lastly, does anyone know what symptoms you'd get from a faulty fuel pressure regulator? Thanks again for your help people, I'd be stuck without these answers. |
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| cosser | Sun Mar 25, 2012 10:22 pm Post #7 |
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Hi Will, have you took the fuse out and the plastic cap off..?? The fuse contacts have to slide through the housing to get it apart..!! They are quite a snug fit but it should come off quite easy..get the part numbers off the hose and rubber housing that you mention..and check on the mercedes parts site..Inchcape..sorry I don't have a link..!! You may find they're reasonably priced..for mercedes anyway..lol.. if they're not then you may be able to get them from a member who has spares lying around..They may be a dealer only ..?? Cosser..!! |
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| stwat | Sun Mar 25, 2012 10:35 pm Post #8 |
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The rubber housing is surprisingly cheap from MB Link to the MB parts site Don't forget we get an extra discount off any parts from there to by using discount code 190 owners All the other hoses and pipes part numbers can be found Here Edited by stwat, Sun Mar 25, 2012 10:41 pm.
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| cosser | Sun Mar 25, 2012 10:56 pm Post #9 |
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Nice One Stu..!!
Edited by cosser, Sun Mar 25, 2012 10:57 pm.
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| WillTepper | Mon Mar 26, 2012 9:02 pm Post #10 |
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Brilliant, thanks chaps. I'll let you know how I get on! |
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| WillTepper | Tue Mar 27, 2012 6:21 pm Post #11 |
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She lives! Thanks to all who helped with this. After I stripped everything down, I cleaned everything, adjusted the air metering plate, sorted out the vacuum leaks and voila, she's running better than before. Result
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| stwat | Tue Mar 27, 2012 8:47 pm Post #12 |
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That's good to know. |
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| jeremy | Tue Mar 27, 2012 10:04 pm Post #13 |
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Too Far Gone To Help
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Wonderful , well done . Now can you do all of ours ? Only another 400 or so to go !! Jeremy |
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| cosser | Thu Mar 29, 2012 7:14 pm Post #14 |
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Hey will, did you take detailed pictures and make scientific step by step notes.??..can you do a walkthrough for the rest of Us..lol..!! Glad to hear you got it sorted..!! Cosser..!! |
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| brocstar | Thu Mar 29, 2012 9:00 pm Post #15 |
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andy
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my motor is as lumpy as you like on tick over, got to keep the window up in case it shakes me out of the seat on to the road (got mot on sat) what bits did you replace and how much cheers |
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| WillTepper | Fri Mar 30, 2012 2:35 pm Post #16 |
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I didn't take pictures, but I did make notes, so I might do a walkthrough in about 2 weeks' time (I don't have the notes with me). Brocstar I didn't actually replace anything, I was going to but I was getting impatient and I didn't really have the money, so I ended up sealing vacuum leaks with RTV sealant... Don't judge me. I'd have needed to replace the rubber air housing under the air flow metering plate, the rubber pipe between this housing and the IACV and ideally the IACV itself. And the injectors. That said, checking all your sensors with a multimeter, sorting out your vacuum leaks and adjusting your AFM should see an improvement on most cars I'd imagine. Good luck with the MOT. |
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| WillTepper | Tue Jun 12, 2012 4:06 pm Post #17 |
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Well it's been a while, and I no longer own a 190 (or even a Merc) ![]() However, I have found the notes I made on doing this, and what follows is my attempt at a write-up. It is by no means 100% accurate, I've probably left some stuff out, but hopefully it will be helpful to those lucky enough to be driving a 'Benz with the KE-Jet injection system. So, the first thing I found was a list of things I thought I should check to try to sort the issue out. -OVP Relay (you can bridge the terminals in the socket it fits into using a bit of wire with crimp-on bullet connectors at either end) -Distributor, plugs (should have 0.8mm gap) -Idle air control valve and associated pipework (check IACV for free movement, clean with carburettor cleaner if necessary) -Rubber boot below the air flow meter plate. This can deteriorate with age, check the rubber boot and all the pipework attached to it very thoroughly and replace anything you think might be leaking. Vacuum leaks here can cause real trouble. If you don't want to spring for replacement parts, you can use RTV automotive sealant for some repairs. I did, and it worked fine, but I can't comment on how long it will last. If you're going to the trouble of fixing it, you might as well replace any dodgy hoses. -Fuel pressure regulator. I don't actually know how to check this, I only included it on the list because I read a post on a different forum where a guy was having similar troubles and it turned out to be the fuel pressure regulator. Something to think about I guess. -Thermo switch. This is located on the cylinder head near the thermostat outlet. It should have 4 pins, doesn't matter which way the plug goes on. To check it, measure the resistance of the pins diagonally. With a cold engine, the resistance should be 2.3-2.8 k. ohms iirc. Someone may wish to double check this. That was my list of things to check. I will have undoubtedly left some things out, so please do your own research and don't treat it as an exhaustive list. The other, much more oily piece of paper that I found has vague notes that I made to help me put everything back together. As a result, it is not complete but gives a pretty good idea of the steps involved in stripping down the fuel injection system. -Undo the various nuts & bolts holding the air filter housing to the engine. You will also have to remove the inlet air temperature sensor and probably some breather hoses as well, depending on your engine. Once you've removed all the bolts, the bottom half of the air filter housing fits around the air metering plate with a rubber seal. Pull it off carefully. -Take off all breather hoses that you can get to. -Remove all the metal fuel lines. To take them off the injectors, undo the bolt holding the metal plate that holds in each pair of injectors. Remove the metal plate then, while counter holding the body of the injector with another spanner, remove the fuel line. The injectors just pull out at this point, so if you want to take them out now is a good time. Make sure to plug any open ends of fuel lines or injectors, I used little wads of kitchen towel. While you're doing this, you can also remove the fuel pressure regulator. -Remove the 2 electrical plugs from the fuel distributor / metering head. -Undo 3 star-drive bolts then remove the fuel distributor. Be careful not to lose the rubber o-ring that goes between the fuel distributor and the air flow meter. -Undo 3 bolts on the throttle cable bracket and disconnect one of the ball joints in the assembly. This should allow you to move the whole assembly to one side without disturbing the adjustment of the throttle cable. -My notes at this point just say 'air flow meter out'. I know you have to undo a jubilee clip that holds the rubber boot under the air flow meter onto the throttle. I would assume it just pulls out at this point, but be careful, don't force anything and make sure you've undone any nuts and bolts holding it in place. -At this point you can probably remove the idle air control valve. It doesn't say anything in my notes about what point in the procedure I removed it, but it's quite tricky to get to with the injection system in the way. It should have 2 hoses coming off it, and an electrical connector. Once you've removed these, just pull the IACV out. It sits between 2 branches of the inlet manifold, held in by a shaped piece of rubber. -Now you should be able to see the throttle. Be careful not to let any dirt get into the inlet manifold. There should be a wire coming off the throttle, follow it to a plug and unplug it. Remove the 2 bolts that hold the plug in place. There should also be some vacuum lines coming off the throttle, gently disconnect them noting their locations. My notes say 'SPRING', so I would assume there's a spring to remove as well. At this point you can remove the 4 bolts that hold the throttle assembly in place then remove the throttle. You're supposed to cut a new section of gasket when you replace the throttle, I just reused the old one and it seemed fine. Removing the throttle isn't necessary, but I wanted to clean and inspect it. I also checked the resistance of the sensor on the side of the throttle. I believe it was just a switch, so no resistance when the throttle was closed and no conductivity with the throttle open. Could be the other way round? At this point you should have most of the components of the KE-Jet system extracted from your vehicle. Give everything a good clean and check your air metering plate zero position. There are guides that cover this elsewhere on the forum. To change its position, you will need to remove the rubber boot from the air meter assembly. Just take off all the bolts that hold it on, but make sure to replace them in the same place. I drew the outline of the air meter onto a cereal box and poked the bolts through in the same places they came from. Make sure there are no air leaks in the rubber boot, especially where the hose from the IACV joins it. That should be it! Once you've cleaned and adjusted everything, put it all back together and hopefully you'll see a pretty significant improvement. I cannot stress enough how important it is to be organised if you decide to give this a go. It's not particularly difficult, but if you don't make notes and organise everything you take off in a logical order, you will struggle to put it back together. As with any task on a car, take your time, and if things start getting tricky or you start to lose focus, go have a sit down and a cup of tea (or coffee, in my case). I think that's everything, I know this isn't completely accurate so do not treat it as such. I have written this for the benefit of everyone on here, or indeed anyone who might find it useful. Please add pictures, edit it, copy it and generally do whatever you want to do with it. However, please do not contact me personally for help with this. I am happy to work with people to get this guide up to scratch, but once it's of a good standard I intend to leave it at that. Thanks to those who helped me resolve the issue in the first place. |
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![]](http://z2.ifrm.com/static/1/pip_r.png)
) and giving it some throttle. It ran, but you needed to keep the revs up otherwise it would die, but after a while it settled down and would just about idle, and I drove it home like that.






8:36 PM Jul 11