julians Posted January 27, 2005 Share Posted January 27, 2005 A brief synopsis:- Car started witha very slight misfire a few weeks ago, that over the course of 200 or so miles developed into very rough running/popping banging flames etc, now the engine wont start. Heres a list of everything I've done:- -Compression test is fine on all 4 cylinders -Alternator is disconnected -coil pack replaced -crank sensor replaced -resistance across all 4 injectors is equal -fuel filter replaced -spark plugs replaced -Ht leads replaced -ECU talks to laptop OK, and reports various sensors ok. -timing belt has not slipped. -fuel pump is running. Its a zetec 2.0 on dta 3d managed injection. Anyone got any more suggestions? If anyone has a fuel pressure guage I could borrow it would be much appreciated. Link to comment Share on other sites More sharing options...
Bob Simon Posted January 27, 2005 Share Posted January 27, 2005 Just a guess... Electrical noise on the crank hall effect sensor circuit. Make sure the leads are a sufficiant distance from HT leads and that connectors and such are in good shape. I fought this one with an C20XE engine. Caterham had routed the crank sensor wire through the sparkplug cover. I moved the sensor cable to the frame rail and no more problems. Hope this helps. -Bob 95 HPC VX Link to comment Share on other sites More sharing options...
caterhamnut Posted January 28, 2005 Share Posted January 28, 2005 ...and you can read all about a similar problem I had (but with a 'K') here Big update! here 77,777miles in 3 years Link to comment Share on other sites More sharing options...
julians Posted January 28, 2005 Author Share Posted January 28, 2005 I guess its possible that it could be electrical noise on one of the wires, but nothing has changed to cause it. However I will pursue that line of questioning over the weekend, cheers. Link to comment Share on other sites More sharing options...
Tony Martyr Posted January 28, 2005 Share Posted January 28, 2005 I think suspicion of the crank sensor is well placed since it is the one device that can produce all of your symptoms. You don't know it anything has changed - you have not changed anything but that is not the same thing. Link to comment Share on other sites More sharing options...
julians Posted January 28, 2005 Author Share Posted January 28, 2005 But I've replaced the crank sensor with a new one, so it cant be the sensor itself. There could still be a problem with the wiring to the crank sensor though, this will be the focus of my attentions this weekend. Link to comment Share on other sites More sharing options...
julians Posted January 28, 2005 Author Share Posted January 28, 2005 The only other things that could be causing it ( ithink, correct me if I'm wrong are) faulty injectors (unlikely for all 4 to fail, if one failed the engine would still run??) Faulty fuel pressure regulator - need a pressure guage to check this. Faulty ECU (but it talks to the laptop OK, but I guess this doesent neceserily prove the entire thing is functioning correctly) Dodgy battery - its an oddysee battery, and I would have thought that if it can turn the car over, it should be healthy enough to fire the sparks and run the ecu - is this a valid assumtion or not? Link to comment Share on other sites More sharing options...
Bob Simon Posted January 28, 2005 Share Posted January 28, 2005 My crank sensor problem was very spotty. The original car builder couldn't get the engine to start or tickover for about a week after install. Lots of backfires, spitting, and such...no start. One day it started with no problem! After that the car worked well at first, but as more miles went on the car, occasionally the engine would have problems. Sometimes it worked great, other times not. Injectors, fuel pressure, Battery? Symptoms don't add up to me. From what I've been told, when an ECU shoot craps it's usually because the smoke leaked out of one of the IGBT outputs. You get no 14 spark, 23 spark, or no fuel. -Bob 95 HPC VX Link to comment Share on other sites More sharing options...
julians Posted January 28, 2005 Author Share Posted January 28, 2005 Its not the battery, just fully charged it and it turns the engine over at a rate of knots. I'm almost certain its electrical, dont have anything concrete to go on, just a hunch. Today I removed and inspected the wiring loom for all the engine sensors, all wires physically look ok, no nicks etc, I tested continuity on the crank sensor wire, all was well. Re routed them well away from HT (even though the routing of them hasnt changed in years). Still no success. Most of the time when trying to start it will spit and backfire and never actually catch and run , occaisonally, it will catch and run for a few revolutions before dieing Bob, could you elaborate on your last sentence? I dont quite follow, are you saying it sounds like a dead/dying ECU? This is a conclusion I'm slowly coming to, I may end up sending it back to DTA for a test/repair. Its frustrating because you only get so many attempts before the battery dies, and you have to give up and recharge it. Link to comment Share on other sites More sharing options...
blade_runner Posted January 28, 2005 Share Posted January 28, 2005 Are you sure there are no leaks in the exhaust or on the induction side? leaking exhaust and over fueling will cause popping and flames from the exhaust. rough running if all the electrical system has been checked could be something as simple as an air leak on the induction side? 'Pinky Pics' here Link to comment Share on other sites More sharing options...
julians Posted January 28, 2005 Author Share Posted January 28, 2005 Fairly sure there are no air leaks, but will double check. Its not so much rough running as no running at the moment. Link to comment Share on other sites More sharing options...
RESOLVIWOLF Posted January 28, 2005 Share Posted January 28, 2005 julian, when i had my problem (very very similar symoptoms) a chap whose dealt with this type of things for over 30 years heard teh car run and immediately said: either: 1) crank sensor 2) dry joint somewhere like in the loom or ecu youve replaced the crank sensor but have you checked the wiring liek back to the ecu Link to comment Share on other sites More sharing options...
Bob Simon Posted January 29, 2005 Share Posted January 29, 2005 Bob, could you elaborate on your last sentence? I dont quite follow, are you saying it sounds like a dead/dying ECU? This is a conclusion I'm slowly coming to, I may end up sending it back to DTA for a test/repair. Sure. I don't think it's your ECU. What I meant to say is that if the ECU outputs are knackered, it's very likely you won't get spitting, flames, pops, backfires and such. It just plain won't start. When you changed plug leads you did get the proper resistor types didn't you? (approx 2Kohms) If they're Beru leads, they have solid copper wire that requires resistor booties on *BOTH* ends of the lead. If the conductors are of the carbon resistor type, then resistor booties aren't needed. Make sure you're using resistor type spark plugs as well. Oh yeah, take it easy on the starter while you're trying to debug your problem. Overheating the starter in a fit of frustration can zorch it pretty quick. Don't ask how I know... ☹️ -Bob 95 HPC VX Edited by - Bob Simon on 29 Jan 2005 00:12:53 Link to comment Share on other sites More sharing options...
julians Posted January 29, 2005 Author Share Posted January 29, 2005 The plug leads are direct replacements from halfords, so they should be fine, although I do have an old set that I can try and I've already broken one starter. Jackal, will be thoroughly checking the wiring today. I have mate coming round to help, so hopefully with another pair of eyes/hands we can get this cracked. Link to comment Share on other sites More sharing options...
John Howe Posted January 29, 2005 Share Posted January 29, 2005 Could the odd attempt to fire indicate a lack of fuel, caused by a blockage? I've had petroleum jelly, in the shape of sausages (no comments please), floating around in the fuel tank, flattening the filter and completely sealing the fuel tank. Just a thought JH Deliveries by Saffron, the yellow 222bhp Sausage delivery machine Link to comment Share on other sites More sharing options...
julians Posted January 29, 2005 Author Share Posted January 29, 2005 Could be, thats also something I'll be looking into today. Going to take the injectors off the throttle body and watch them to see if they squirt fuel. Link to comment Share on other sites More sharing options...
julians Posted January 29, 2005 Author Share Posted January 29, 2005 Ok, it runs now (but I havent changed anything), but only just, lots of pops and flames. Check the fuel injectors , they are working fine, nice atomisation. The symptoms are exactly the same as when my alternator failed and the battery got low on power a couple of years ago, however this time the alternator is working fine (14.2v when engine running). My current thinking is that a power connection to the ECU, or an earth strap is corroded and hence not allowing sufficient current to flow, hence giving similar symptoms to a flat battery whilst the engine is running. However the starter turns the engine over just fine, so obviously that is getting sufficient current. So tomorrow I will be cleaning every connection to the battery and every earth strap. Is my thinking sound do you think? or am I clutching at straws? Link to comment Share on other sites More sharing options...
Bob Simon Posted January 29, 2005 Share Posted January 29, 2005 Jumper a battery lead to the ECU bypassing the car's loom. If there's a corroded bit in there someplace, this would make the engine smooth out.' -Bob 95 HPC VX Link to comment Share on other sites More sharing options...
julians Posted January 30, 2005 Author Share Posted January 30, 2005 Hooray, its fixed. Turned out to be a loose bolt attaching the earth strap from engine to chassis. What a pain in the arse!! Link to comment Share on other sites More sharing options...
caterhamnut Posted January 30, 2005 Share Posted January 30, 2005 Glad it is sorted - if you read our story you will have seen that it is often the simplest thing that stops the car - took us about 6 months to figure ours out - earths (all of them) are the first thing to check 😬 - of course you know that now! Big update! here 77,777miles in 3 years Edited by - angus&tessa on 30 Jan 2005 14:06:56 Link to comment Share on other sites More sharing options...
Chris__ Posted January 30, 2005 Share Posted January 30, 2005 Link to comment Share on other sites More sharing options...
Bob Simon Posted January 30, 2005 Share Posted January 30, 2005 *thumbup* Link to comment Share on other sites More sharing options...
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