Toby85 Posted February 18, 2014 Share Posted February 18, 2014 Hi. As some may have seen in the introductions section, I have a high mileage project car a little rough around the edges which I am doing up. However, it is a little rough running, as I'll explain. Problem is I find it hard to tell if it's misfiring or not - I've never really heard one running its best before so can't tell what it should be acting like! It fires up straight away every time but the idle sounds a little unsure, very low, a touch rough. It will rev up reasonably keen. However, the idle seems to randomly jump up for a while, then maybe drop back down for a bit, as I said - seems unsure of itself! Then the engine management light came on and it wouldn't rev over 2,500, seemed to put itself in to limp mode! I cycled it off and on and the light is still on but it's running as it was before. I've just changed the plugs and cleaned the MAF. I'm lost and really need help - anyone local be able to offer any help or advice?! I'd just like to hear a z running normally, or plugging it into diags would be brilliant but I can't get it to a garage as it's not insured. I'm in the west mids, DE11, if anyone who knows these could help if be more than willing to swing them some beer tokens! Thanks for all advice in advance, Toby Quote Link to comment Share on other sites More sharing options...
rothers2901 Posted February 18, 2014 Share Posted February 18, 2014 Did it run OK before the plug change and Maf cleaning? Make sure the coil packs are correctly connected to the plugs and all the electric coil pack connector are securely placed onto their right places. Try removeing each coil pack connectors in turn to see if there is any change in the running of the engine. Quote Link to comment Share on other sites More sharing options...
bamdc2 Posted February 19, 2014 Share Posted February 19, 2014 here is the link on how to do the pedal dance so you can read the codes as well as the list of codes so you can find out what is the problem. http://www.350z-uk.com/topic/45371-cel-light-on-safe-to-drive/ Quote Link to comment Share on other sites More sharing options...
Toby85 Posted February 19, 2014 Author Share Posted February 19, 2014 That's superb, thank you. Real fear is that it's a lack of compression, would this throw the engine intermittently in to limp mode? I'll have to borrow a compression tester if nothing conclusive comes off stamping on the pedal in an erratic fashion, fingers crossed. Really don't want to start messing with piston rings or valve seats. Quote Link to comment Share on other sites More sharing options...
Toby85 Posted February 19, 2014 Author Share Posted February 19, 2014 Oh, and thanks for the advice regarding coil packs - I tried disconnecting the 3 on the drivers side which definitely made a difference, I can't get my hands down the side of the inlet pipe work to disconnect the other bank though! Cleaning the maf and changing the plugs had no effect whatsoever. If it is low compression on one or more cylinder could I expect to see a blue smoke from the exhaust, especially from a cold start? All I'm getting is a bit of white which I assume to be condensation rather than burning water 1 Quote Link to comment Share on other sites More sharing options...
R35LEE Posted February 19, 2014 Share Posted February 19, 2014 Read the codes before you reset eml. Could be crank sensor, MAF knackered, coil pack(s), IPDM, ECU and like you said the worst of all compression issue, but unless its been right down on oil I don't think it will be this. Quote Link to comment Share on other sites More sharing options...
Toby85 Posted February 19, 2014 Author Share Posted February 19, 2014 Ok, good news is I got a code! Bad news is it's not in any way helpful. I got 300, which I assume is p0300, apparently a random misfire. I guess I need to try a coil pack next! Quote Link to comment Share on other sites More sharing options...
Toby85 Posted February 20, 2014 Author Share Posted February 20, 2014 Actually, I'm going to try a compression test before I spend any more money. I'm not going to carry on throwing money at it randomly when there could be a serious underlying issue! Quote Link to comment Share on other sites More sharing options...
Toby85 Posted February 21, 2014 Author Share Posted February 21, 2014 Ok, compression test done (dry and the results are all within spec (just) at 160 lowest and 175 highest, which I'm sure won't be throwing the random misfire 0300 error. I also unplugged one coil at a time whilst running and each made an obvious misfire so it doesn't even seem to be misfiring to me! So confused. Quote Link to comment Share on other sites More sharing options...
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