Hhornsey98 Posted March 10, 2018 Report Share Posted March 10, 2018 Hi ive got a 2003 siat arosa 1.0 with a misfire on cylinder 1 and 2 spark plugs leads and coil pack has been changed and still no different anyone got any ideas what it could be runs and drives but cuts out when left to idle Quote Link to comment Share on other sites More sharing options...
Sausage Posted March 10, 2018 Report Share Posted March 10, 2018 (edited) Does it stay on 2 cylinders or revert back to 3 or 4? Error codes? Confirm spark on 1 and 2, confirm fuel at 1 and 2, do a compression test (burnt valves, head gasket etc). TB might need alignment procedure if you have cleaned it. Edited March 10, 2018 by Sausage Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 10, 2018 Author Report Share Posted March 10, 2018 No stays on 2 cylinders got 3 faults on reader cylinder 1 misfire cylinder 2 misfire and radon multiple misfire found a foul on cylinder 1 injector wiring but surely that wouldnt cause 2 cylinder misfire Quote Link to comment Share on other sites More sharing options...
Sausage Posted March 10, 2018 Report Share Posted March 10, 2018 Fix the issues with the injector wiring if you have any that might be a problem. If the plugs are wet on the duff plugs after a run then fuel is getting thru though. Compression test next, buy a kit (£20) if you dont have access to one, no point paying someone to do it for more than a kit costs. Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 10, 2018 Author Report Share Posted March 10, 2018 Will do that today but got told it could be a camshaft position sensor or lamba sensor causing the issue had a pending fault with emmisons Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 10, 2018 Report Share Posted March 10, 2018 permanent missfire or only sometimes? only when cold and goes when warmed up? did it start missfiring suddenly or get worse and worse over the last few days/weeks? what do the plug tips look like (colour)? Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 10, 2018 Author Report Share Posted March 10, 2018 Constant misfire will drive fine when acclerating then splitters and strggles then dies on idle the tips dont look to bad tbh Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 10, 2018 Report Share Posted March 10, 2018 sounds like when at WOT, its ok. that'd be compression my guess. compression test needed. yeah, valves or more likely HG. you could swap injectors round to eliminate them being the problem. so instead of 1&2, swap to 1&3... unlikely to be TB. not cam or crank sensor. O2 also fine. Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 10, 2018 Author Report Share Posted March 10, 2018 4 bar in cylinder 1 4 and half bar in cylinder 2 4 and half bar cylinder 3 10 bar cylinder 4 Seems odd to me Any suggestions? Quote Link to comment Share on other sites More sharing options...
Sausage Posted March 10, 2018 Report Share Posted March 10, 2018 (edited) Redo with WOT and all plugs out 10 seconds cranking to confirm but that is knackered. Head off after confirmation. Head gasket, valves, piston rings most likely suspects. Has it overheated? Edited March 10, 2018 by Sausage Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 10, 2018 Author Report Share Posted March 10, 2018 10 seconds no plugs i got 6 bar on cylinder 1 6 on cylinder 2 6 and half on cylinder 3 7 and a half on cylinder 4 Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 10, 2018 Report Share Posted March 10, 2018 (edited) agreed with what sausage says... yeah, basically the pressure in 'bar', you can approximate to compression ratio. so if you get about 10 bar, that is about 150psi which is about right. so it does look like something is way out. and when testing do it with a hot engine. they're all low, which isn't good. Edited March 10, 2018 by mk2 Quote Link to comment Share on other sites More sharing options...
Sausage Posted March 10, 2018 Report Share Posted March 10, 2018 Redo with wide open throttle (wot) and use PSI, cyls need to be within 10% ideally. When i did a compression test on a 1.0 it was 150 psi on all near enough. 6 bar = 87psi 7 bar = 102psi. Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 10, 2018 Author Report Share Posted March 10, 2018 Same wet and dry heads coming off now Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 10, 2018 Report Share Posted March 10, 2018 like to see pics where the seal has failed... bet it's between the cylinder webs Quote Link to comment Share on other sites More sharing options...
Rich Posted March 11, 2018 Report Share Posted March 11, 2018 just buy another engine, cheapest option with the 1.0 crap. you may think this is hasty but I have done a few and once you begin then you will just be chasing yourself forever. head gasket will be fine, doubtlessly it has just chosen to give up having compression. what's the mileage on it? Motorways? they rev too high for the cheap components. This applies to all lupos bar the diesels, change the running gear constantly and they rule engine wise. Quote Link to comment Share on other sites More sharing options...
Sausage Posted March 11, 2018 Report Share Posted March 11, 2018 Rich is spot on as usual, it will be cheaper to find another engine than fix this one, but you can learn plenty by finding the problem on this one before making decisions. But seriously just find another engine. Quote Link to comment Share on other sites More sharing options...
mattarosa Posted March 11, 2018 Report Share Posted March 11, 2018 https://m.ebay.co.uk/itm/vw-volkswagen-polo-6n2-1L-mpi-auc-engine/323066466814?hash=item4b384311fe:g:eoYAAOSwSYpZypjt Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 16, 2018 Author Report Share Posted March 16, 2018 Head gasket had failed between cylinders and 2 exhaust valves burnt out relapped all valves and replaces exhast valves only been a 30 pound job up to now will be starting it up tomorrow just few bits to finish Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 16, 2018 Report Share Posted March 16, 2018 wow that was bad... looking much better now! i bet the engine will purr with freshly lapped valves. good job! if it's still in pieces, you could balance up the combustion chambers and very slightly radius that cut edge next to the valves. will give you slightly better idling and slightly better efficiency (but not more power). to do that you'd need to skim the block or head by 3-5 mm or so (and alter the cam timing a fraction). Quote Link to comment Share on other sites More sharing options...
Hhornsey98 Posted March 16, 2018 Author Report Share Posted March 16, 2018 Heads allready been skimmed ready to go on im redoing timing as rather set it up myself than go of what it was running with then I know for sure but hoping it runs sweet as a nut now Quote Link to comment Share on other sites More sharing options...
Rich Posted March 16, 2018 Report Share Posted March 16, 2018 fill the bores with a nice even amount of diesel overnight & check again in the morning. Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 16, 2018 Report Share Posted March 16, 2018 44 minutes ago, Rich said: fill the bores with a nice even amount of diesel overnight & check again in the morning. you mean combustion chambers? or do you think the rings are glazed...? I hadn't thought of that Quote Link to comment Share on other sites More sharing options...
Sausage Posted March 18, 2018 Report Share Posted March 18, 2018 Noice. Quote Link to comment Share on other sites More sharing options...
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