AndrewGP Posted May 4, 2012 Share Posted May 4, 2012 My car is currently being looked at and has everyone stumped. Rather than update the other thread I started which was getting very confusing, I thought I'd just ask a simple question in the hope of an answer! Problem: My 1.8 K Series, running on RBTBs is running rich. Range is poor and it smells very rich especially at idle. This is a new problem and so I do not think it is mapping related as it was mapped way back in 2007. Facts: The lambda, which is running in No4 primary (decat fitted to the exhaust) is very black. No 4 plug is different in appearance to 1,2 and 3. No 4 exhaust gas temperature is way below 1,2 and 3 for the same RPM. Things checked and eliminated: Inlet manifold gasket OK, injectors and wiring OK, coil packs and wiring ok. Spark plugs swapped around, all OK. Leak down test shows all OK with No 1: 15%, No 2: 20%, No 3: 15% and No 4: 15% Does anyone (Oily!!?) have any ideas what's going on? Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted May 4, 2012 Share Posted May 4, 2012 Do the roller barrels have to be aligned/balanced so they all open together with no variation ? Could one be out of kilter so they are fighting each other ? Link to comment Share on other sites More sharing options...
charlie_pank Posted May 4, 2012 Share Posted May 4, 2012 your symptoms imply that one cylinder is getting more fuel than the others. Either that or it's not burning the fuel in that cylinder. More fuel to 1 cyl: I know you have already swapped the injectors about, so that could only be caused by a wiring/interference problem to that injector or the other 3. Could you try another head loom? I think I might have one downstairs if you're interested. Not burning: Is there an problem with your cooling system so that one cyl is much cooler? Have you fixed the compression issue? what about something up with LT side of coil feed - that'll be head loom again! Interestingly, it sounds like you have another problem which is that the lambda probe is on cyl 4 yet this is the one that's running with the wrong mixture, so it sounds like your map needs revisiting too. Link to comment Share on other sites More sharing options...
AndrewGP Posted May 4, 2012 Author Share Posted May 4, 2012 Quoting Stationary M25 Traveller: Do the roller barrels have to be aligned/balanced so they all open together with no variation ? Could one be out of kilter so they are fighting each other ? RBTBs already balanced, it was the first thing we tried ☹️ Link to comment Share on other sites More sharing options...
millsn Posted May 4, 2012 Share Posted May 4, 2012 just a thought but is no.4 short on air versus the rest? I/.e. if you look down the barrels are all rollers open the same amount relative to each other? It may be nothing to do with the amount of fuel being dispensed Link to comment Share on other sites More sharing options...
millsn Posted May 4, 2012 Share Posted May 4, 2012 on balancing I suspect you can only balance each pair of rollers relative to the other pair - have you looked up the barrels bores? Link to comment Share on other sites More sharing options...
johnv Posted May 4, 2012 Share Posted May 4, 2012 TPS? if the map is sensitive to the TPS voltage and it has worn out it will dump more fuel in .. ask me how I know! Link to comment Share on other sites More sharing options...
AndrewGP Posted May 4, 2012 Author Share Posted May 4, 2012 Charlie All sounds sensible. We did swap the inector wiring around with the original injector in place, but I will get them to check the wiring again. Thanks for the offer of the loom, I'll keep you posted. Millsn The RBTBs were checked with flow meters and we pretty spot on at idle and throughout the rev range, so I don't think that it sadly. Johnv We did hook the car up to the laptop and the TPS voltage was fine. It also wouldn't explain why one cylinder is rich with respect to the other 3.... keep the ideas coming though please :) Link to comment Share on other sites More sharing options...
millsn Posted May 4, 2012 Share Posted May 4, 2012 how does it actually run? Link to comment Share on other sites More sharing options...
millsn Posted May 4, 2012 Share Posted May 4, 2012 I take it the HT leads are new/okay Have you changed/swapped//modified anything at all recently? Link to comment Share on other sites More sharing options...
AndrewGP Posted May 4, 2012 Author Share Posted May 4, 2012 Quoting millsn: how does it actually run? It actually runs very nicely indeed. Idles well and pulls like a train. If it wasn't for the fact that something significant has changed, causing the poor range and fouling the plugs etc, I would be tempted to leave it! I forgot to mention Charlie, the compression issue hasn't been fixed, Neil Garner have done a leak down test in addition to that test. Bearing in mind we swapped the coil packs and leads over with no change could it still be related to them? Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted May 4, 2012 Area Representative Share Posted May 4, 2012 Could be as simple as a faulty fuel pressure regulator Link to comment Share on other sites More sharing options...
millsn Posted May 4, 2012 Share Posted May 4, 2012 is it fouling all plugs or only no.4? Link to comment Share on other sites More sharing options...
charlie_pank Posted May 4, 2012 Share Posted May 4, 2012 I had a look, I've only got the injector loom not the spark side. Still might solve your problem though My comment about the LT side of ignition is that there is a feed from ECU which tells them when to spark, if this message doesn't get through, then no ignition. Thinking further though, is it wasted spark? if so then such a faultwould affect a pair of cylinders rather than just 1. Compression: if the bad cylinder is down on compression it's not going to burn as well as the others. If the other 3 are running fine but the lambda sits in #4 then it was mapped with this problem in place or it's not using the lambda input to determine fueling. Link to comment Share on other sites More sharing options...
AndrewGP Posted May 5, 2012 Author Share Posted May 5, 2012 Thanks everyone for the replies so far, much appreciated. I think the next avenue is to get it back on the laptop and look at the map, TPS, lambda etc again as suggested. Failing that I think the head may have to come off to see what's physically going on. At least the leak down test is not pointing to cracked piston ring lands, so fingers crossed the bill might be a bit less than I was preparing for Link to comment Share on other sites More sharing options...
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