T2 MSW Posted July 19, 2015 Share Posted July 19, 2015 (edited) Odd issue that I can't get my head round. I have a misfire on Cyl 3 that started intermittent and now is perminent. Im getting fuel as you can hear the unburnt fuel in the exhaust and the plug is clean. Plugs are brand new (Almost) NGK racing plugs and all look in good shape Swap coilpacks to different cyl and the problem stays on 3 Swap plugs round and prob stays on 3 Using the output testing on the syvecs I have tested all cyl and I get a spark at each one. Checked the coil pack connector and adjusted the connector gaps - they are fine So its almost like when the car is running the ECU is not firing 3?? But if it did shut down a cyl (not sure that it does) i would expect an error or warning. Edited July 19, 2015 by T2 MSW (see edit history) Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 Answered my own question ref the ECU shutting down a cylinder. It can't as it does not have any misfire detection/strategy. And if it did it would shut down both spark and fuel. Looks like my issue is with a sticking injector. Changed it with No.2 and the issue followed it. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2015 Share Posted July 20, 2015 Scrub the below, I see you think it's an injector issue now, just left the reply for reference. Is number three plug sparking at cranking? You need to ascertain if the Syvecs is driving the coil to ground, and if not, whether it's a wiring / connector issue, or an internal ECU fault. Ask Syvecs if the ecu can be re mapped to use another output to drive coil 3 to test the ecu driver itself. I am assuming an electrical issue here, you have done a leak down test on the offending cylinder of course? Burnt valve comes to mind..... Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 Cheers for the reply Chris. Move injector and the issues follows it. The Syvecs has an output testing mode so you can send a pulse request to each injector and coil to test the outputs are working. They all check out on my car. If needed there would be no reason you could not change the output if one did fail for example as all the inputs/outputs you can program. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2015 Share Posted July 20, 2015 My only advice is to ONLY buy OE injectors, not the re drilled junk that seems to give so much trouble. And to buy ones no bigger than the engine power output realistically needs. People seem to always think bigger is better, whereas a huge injector is much harder to precisely control for low flow requirements at idle and cruise, where a road car engine spends the majority of its time. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 My only advice is to ONLY buy OE injectors, not the re drilled junk that seems to give so much trouble. And to buy ones no bigger than the engine power output realistically needs. People seem to always think bigger is better, whereas a huge injector is much harder to precisely control for low flow requirements at idle and cruise, where a road car engine spends the majority of its time. Yeah completely agree Chris. My car has ASNU 1100CC injectors in which I know are big but I run Ethanol in the car and it requires that size as the 1000's would not flow enough fuel when running the ethanol. Im going to get them cleaned and flow tested just working out the logistics. Quote Link to comment Share on other sites More sharing options...
mellonman Posted July 20, 2015 Share Posted July 20, 2015 cleaning and testing money would be better spent buying a complete new set , having them cleaned and test is around £150 and they could come back as being still bad Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 cleaning and testing money would be better spent buying a complete new set , having them cleaned and test is around £150 and they could come back as being still bad Why? ASNU are testing them and its £15 per injector. They will replace anything thats required and then just add the parts to the bill. A new set would be over £700 and prob have to get the car remapped. Have not got the time or the money TBH. Quote Link to comment Share on other sites More sharing options...
Steve Posted July 20, 2015 Share Posted July 20, 2015 Why? ASNU are testing them and its £15 per injector. They will replace anything thats required and then just add the parts to the bill. A new set would be over £700 and prob have to get the car remapped. Have not got the time or the money TBH. How old are the injectors Mike? Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 less than 6 months. Something has failed in the fuel system hence the material being there in the first place. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2015 Share Posted July 20, 2015 Are all the fuel ines PTFE lined? Ethanol will damage the liners of "rubber" lined braided hose, *BUT* the fuel filter should catch any debris so long as there's no rubber lined hose between it and the rail. Take *NO CHANCES* with injectors, a weak cylinder, not seen by the ECU can wreak havoc. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 (edited) Yes everything thats on it is PTFE and ethanol compatible. Its either left over from the fuel rail being drilled (off the car and cleaned) or from a failed fuel pump. Fuel filter will be coming out tonight to check it over and then replaced. Thank you for that very scary picture, Having done a compression and leak down test I'm fairly confident mine does not resemble that Edited July 20, 2015 by T2 MSW (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2015 Share Posted July 20, 2015 It will lap in..... Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 It will lap in..... lol Quote Link to comment Share on other sites More sharing options...
nihontoman Posted July 20, 2015 Share Posted July 20, 2015 Are all the fuel ines PTFE lined? Ethanol will damage the liners of "rubber" lined braided hose, *BUT* the fuel filter should catch any debris so long as there's no rubber lined hose between it and the rail. Take *NO CHANCES* with injectors, a weak cylinder, not seen by the ECU can wreak havoc. Shouldn't pics that grotesque be banned from the forum? seriously though - oh my god. that's terrible :| Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2015 Share Posted July 20, 2015 That's not too bad, could be caused by excess combustion temps (too retarded, too weak), or just a bad exhaust valve to seat sealing that starts blowing. Turbos are rather cruel! If the mixture is weak(excess O2 to fuel ratio) it acts as a cutting torch. If you retard an engine enough, or have bizarre cam timings set, you can make a manifold (and turbo in a boosted engine) glow red hot with no boost at 2000 RPM. If the manifold is red hot in such a case the exhaust valves will be a lot hotter still. Fixing a burnt valve and seat is pretty trivial. But if the head gasket blows out, the blow torch effect will melt the alloy of the head and sometimes the cast iron block or liner periphery, which is a lot harder to fix. It's knowing stuff like this that's important if you are mapping, as is discussed in another post about someone wanting to learn mapping as a career move. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 20, 2015 Author Share Posted July 20, 2015 Have sent off the fuel injectors to be cleaned and flow tested. Also stripped back all the coil pack clips in prep for the new ones with molded wires to be fitted. This is what I found - surprise the coil even worked Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 20, 2015 Share Posted July 20, 2015 Looks like someone has had Scotchlock terminals on the wires at some time in the past. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 21, 2015 Author Share Posted July 21, 2015 Potentially, Will all be sorted on wednesday hopefully, just going to replace them all with moulded units from Lee. Quote Link to comment Share on other sites More sharing options...
Fizzy T Posted October 17, 2015 Share Posted October 17, 2015 Would you usually disconnect the whole loom when soldering on new plugs or just attempt to do it in situ over the engine? I have a bad misfire on my TT and it's driving me nuts, changed the igniter and coils but it's still there so this threads making me think it's either an injector issue or coil pack clip issue now. All the clips look in good condition so I'm hoping it's not them Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted October 19, 2015 Author Share Posted October 19, 2015 Most likely to be coil pack clips or the coil packs themselves. I disconnected all the clips, took them out of the engine recess, the front of the loom has enough slack to pull up. Then put a cover over the engine when I did mine. Ive messed about with the clips before and the ones from Lee with the pre molded wires are just so much easier. Just make sure you get them the correct way round. Quote Link to comment Share on other sites More sharing options...
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