stevie_b Posted May 12, 2009 Share Posted May 12, 2009 I've got a very tricky and intermittent fault with my mk4 fiesta stalling and/or failing to start at all. Here's my post from the fiesta owner's club: I've got a problem with my 1.25 fiesta mk4 that's so far stumped myself and 2 RAC blokes. The car will be fine sometimes, but on occasions when you try to start it after leaving it for an hour or two, or sometimes when I coast up to a junction with the clutch pedal down, the car will stall and will refuse to start. It will crank strongly, but the engine won't fire. When the car has this fault, on the rare occasions it does start, it'll either die within 1 or 2 seconds (literally), or it could cut out at the next junction you pull up at. When it dies, it doesn't cough and splutter, it just dies immediately, as if I've turned off the engine using the key. The RAC guys have tracked it down to the engine supplying a couple of sparks when you crank it over, and then not bothering to supply any more sparks. You can hear the fuel pump working when the ignition is turned on. The RAC changed the coil pack, but that didn't help. The crank sensor has been changed, but that didn't help. There's one error code stored in the ECU according to the digital dash's test mode: code 0115 (engine coolant temperature), but I don't know how long that's been in there, and from what I've read on here it's a common ghost fault. The RAC's diagnostic laptop reported a "ignition/distributor engine speed sensor fault" (or something like that), but only sometimes. When this fault was cleared, it seemed to be pure chance if that fault would appear again in the ECU even if the problem had re-occurred. The RAC's best guess is that it might need a new ECU. Seeing as the forum won't let me search for "ECU" (too few letters), it's difficult to read up on people's ECU-related problems on here. Is it possible to swap the ECU for one from another 1.25 fiesta mk4? Would I need to get Ford to program it in any way? I remember reading on here somewhere about an "ecu upgrade or update", but no details were in the post that I looked at. Could that help, and if so how would I go about applying the update? I'm posting here as well in case anyone's got any ideas, or if anyone works for Ford who can maybe help. I've cleaned the idle control valve several times just in case it was that, but it hasn't helped. Quote Link to comment Share on other sites More sharing options...
adnanshah247 Posted May 12, 2009 Share Posted May 12, 2009 sounds like the ignition sensor. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 12, 2009 Author Share Posted May 12, 2009 I'm not sure it has one of those, although I could be wrong. Do you mean the crank sensor? That tells the ECU what rotational position the engine's in, and *I think* from that the ECU tells the coilpack when to fire a spark down each HT lead. The crank sensor's already been replaced. Replacing the coilpack didn't help either. Quote Link to comment Share on other sites More sharing options...
Pixelfill Posted May 12, 2009 Share Posted May 12, 2009 I had a very similar problem on a 1.4 '94 Escort, with Cfi. This turned out to be an ECU problem and needed what the ford dealership termed a "quick start" modification. Not sure whether this is the same issue. It mainly manifested itself if the car hadn't had enough time to cool down between stopping and restarting the engine, I assume it was a choke setting in the ECU which wasn't taking into account whether the engine had been running, so was literally flooding the engine when it was already warm. May not help, but then again it may. Mike Quote Link to comment Share on other sites More sharing options...
SUPRALOOPY Posted May 17, 2009 Share Posted May 17, 2009 coolant temp sensor. Not the gauge one the one that talks to the ECU. Quote Link to comment Share on other sites More sharing options...
erol_h Posted May 17, 2009 Share Posted May 17, 2009 I had exaclty the same fault on my mk4 fiesta aswell it never stalled on me but when i went to start it the engine would crank but wouldnt start would leave it for a bit try again and it would start fine done it a few times but sold it before it was sorted. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 18, 2009 Author Share Posted May 18, 2009 coolant temp sensor. Not the gauge one the one that talks to the ECU. Ahh, could be. What makes you day that? Is it the 0115 error code, or have you seen this sensor give the non-starting symptoms before? Quote Link to comment Share on other sites More sharing options...
SUPRALOOPY Posted May 18, 2009 Share Posted May 18, 2009 Ahh, could be. What makes you day that? Is it the 0115 error code, or have you seen this sensor give the non-starting symptoms before? Common on nissan, Also a cheap eliminator. Quote Link to comment Share on other sites More sharing options...
SUPRALOOPY Posted May 18, 2009 Share Posted May 18, 2009 0115 is the coolant temp sensor code yes. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 19, 2009 Author Share Posted May 19, 2009 I'll give it a test first with a multimeter. Someone from the fiesta forum has measured the resistance of his, so I'll do the same on mine. Changing it means draining the coolant, not a job I relish due to many hours spent chasing airlocks around in the past. The mk4 (and mk5 I think) fiestas are known for the ECU logging error 0115 even when there's nothing apparently wrong with it. I think it's a software glitch. Many of those fiestas on the road probably have 0115 stored in their ECU. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 20, 2009 Author Share Posted May 20, 2009 coolant temp sensor. Not the gauge one the one that talks to the ECU. I tested the coolant temp sensor yesterday: it's not that that's causing the problem. The car can start fine with the sensor unplugged from the loom (it just causes the ECU to switch the radiator fan on immediately). I did my usual way of reproducing the problem (run the engine up to temperature, leave for 1.5 hours), and it wouldn't start whether I had the coolant temp sensor plugged in or not. The search for the fault continues... Quote Link to comment Share on other sites More sharing options...
Benjy Posted May 20, 2009 Share Posted May 20, 2009 (edited) Being a ford tech, I've never seen "ghost" codes in the DTC memory. This car hasn't got an ECU of sorts, it's a Powertrain Control Module (PCM) as it works on a CAN system. (Lots of different modules talking to one and other) As Supraloopy said, the DTC does relate to an ECT. These fiesta's are easy to bleed, they don't normally get air locks. Just run it for a while with the header tank cap off until the cooling fan kicks in. Should it need a PCM, it will have to be supplied and fitted by a Ford main dealer as the PATS (Passive Anti Theft System/Immobilizer) will have to be reprogrammed at the same time. Best bet is to get it to a main agent for a diagnosis though, could save a lot of titting about and money on guestimating what's wrong with it. Also, if there's only an ECT DTC, there's nowt wrong anywhere else! Edited May 20, 2009 by Benjy (see edit history) Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 21, 2009 Author Share Posted May 21, 2009 Thanks Ben, I'm pretty sure it's not the ECT sensor that's at fault. The car will start (when stone cold) without the sensor plugged in (so for all the PCM knows, I could have removed it and bunged up the hole with chewing gum ): it just forces the PCM to switch on the cooling fan. When I trigger the non-starting problem, the car won't start with or without the ECT plugged in. You're right about taking it to Ford: got it booked into Ford Basingstoke next week: hopefully their diagnostic system will shed some light on it. I've changed the PCM for another (which I purchased with a matching PATS key), but that didn't work either. I tested that the substitute PCM could make the car start and run (which it did), but when the car had been warmed up and left for a while, it was the same story: wouldn't start regardless of which PCM I used. I think the 0115 code only shows up on the digital dashboard display (when you put it in test mode). It didn't show up on the RAC's laptop, and from what you say I'm guessing it won't show up on Ford's diagnostics either. Thanks for all the input though guys: I really appreciate it. If anyone's got any further ideas as to what it could be, please fire away. I'm bang out of ideas. Quote Link to comment Share on other sites More sharing options...
SUPRALOOPY Posted May 21, 2009 Share Posted May 21, 2009 You bring the petrol and I'll bring the matches??? Quote Link to comment Share on other sites More sharing options...
j1mb0b1 Posted May 21, 2009 Share Posted May 21, 2009 Think the going rate for scrap cars is around £80 now... Quit while your ahead Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 21, 2009 Author Share Posted May 21, 2009 Could do. I've only had the car 8 months though, so it seems like a waste. I've just put it through a service and MOT, and had 3 new Falken tyres put on it. Literally driving back from the tyre fitters was the first time it decided to pull the stalling stunt on me. Quote Link to comment Share on other sites More sharing options...
Benjy Posted May 22, 2009 Share Posted May 22, 2009 The car will remember the last temperature the engine was at and stay there if you unplug the ECT. If there's a fault with the car that has been recognised by the PCM, it WILL tell you on IDS. If the car won't start, it will store CMDTC's. In all honestly, you can swap bits and bobs and try to second guess what's wrong with the car, but the only way you'll find out without rebuilding the car from the ground up is to get it connected to IDS, maybe even carry out a Datalogger test. Compared to even the best snap on code readers and AA/RAC diag machines, IDS is well ahead of them in the technology stakes. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 22, 2009 Author Share Posted May 22, 2009 Next Thursday is D-Day for the car: I've typed up a description of the problem, how I've attempted (and failed) to fix it, and how to reproduce the problem. Fingers crossed! I'll post back here what they find... Quote Link to comment Share on other sites More sharing options...
SUPRALOOPY Posted May 22, 2009 Share Posted May 22, 2009 Listen to Ben. He speak good lingo..LOL Quote Link to comment Share on other sites More sharing options...
stevie_b Posted May 27, 2009 Author Share Posted May 27, 2009 Solved it! (well, my next door neighbour's son did). It was caused by a slight leak from the thermostat area dripping onto an electrical multiplug. The plug was fairly well hidden somewhere beneath the coilpack, but I do feel a little bit of a donut for not spotting it myself. Still, neither did the 2 RAC guys... Thanks for all the help and advice folks, it is much appreciated! Quote Link to comment Share on other sites More sharing options...
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