theminiking Posted January 18, 2014 Share Posted January 18, 2014 I've got a strange problem for you. .. I've got a Vortech supercharged Zed and recently took the supercharger and intake pipework off to change the supercharger seals and clean the pipes of any oil residue. Since putting it all back together it now splutters and coughs whenever I try to take it past 4k rpm under load. I can rev through 4k rpm under part throttle and below 4k it behaves perfectly normally. It's not logging any fault codes and having logged the AFR with both Cipher and a Zeitronics data logger it seems spot on right up to 4k and then almost instantly indicates off the scale. I'm guessing that's what you'd expect from a misfire. I thought it could've been the supercharger inlet silicone elbow collapsing under the vacuum and so made up a small ring to fit inside to make it a lot more rigid. Took it out to test and it was cured! Supercharger came out again today to reseal again (think I know where I went wrong last time!) and on refitting took it out for a test drive and the 4k issue is back again! I'm struggling to think what could cause this. Feels too violent to just be one cylinder so that rules out plugs, leads, coilpacks, etc which makes me think it could be fuel related? If anyone has any thoughts or ideas where to look next I'd appreciate your input. Quote Link to comment Share on other sites More sharing options...
Neilp Posted January 18, 2014 Share Posted January 18, 2014 Possible airleak? Have you upset the butterfly valve? Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 Don't think I have an air leak as it's boosting to around 4 psi at 4k rpm Which is about normal and the AFR is spot on up to that point. I've been plagued with induction leaks in the past and this seems quite different. I'm not sure how you'd upset a butterfly valve and wouldn't this give some other symptoms?? Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted January 18, 2014 Share Posted January 18, 2014 Right, let's have a bit more info.... You say AFR goes off the scale at 4k rpm... In which direction? Rich (low numbers) or lean (high numbers)? What is your tuning and fueling set up? The vortech full kit with inline pump, fmu, stock injectors, split second timing etc or tuner with bigger injectors, return fuel system, stand alone ecu or Uprev ? I assume you've done your seals due to burning oil? Have you cleaned the MAF since? Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 Sorry, should be been clearer. AFR is instantaneously hitting the lean end of the scale at 21. Its running 550cc injectors, Uprev MAF and custom map, fuel return system, platinum plugs, walbro pump, plenum spacer and stainless exhaust with sports cats. I had a leak from the supercharger output shaft which wasn't too bad so didn't clean it the first time I resealed it but cleaned it today with a good dose of brake cleaner for good measure which hasn't seemed to help. Quote Link to comment Share on other sites More sharing options...
Adrian@TORQEN Posted January 18, 2014 Share Posted January 18, 2014 hi darren-b here octet's ipad have you checked that the rising fuel pressure regulator is incressing the fuel pressure as the vacuum reduces & the sc makes boost? doesnt sound like a misfire, sounds like fuel starvation to me. so the way to test would be start the car, note the fuel pressure @ idle then disconnect the boost hose. the fuel pressure should instantly rise, blow into the pipe or apply pressure with an air hose, no more than 10psi or so though & the fuek pressure should rise & you should notice a change in the engine note as the engine will run alot richer. Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 Hi Darren, I haven't checked the fuel pressure regulator, that could be my next move. I agree it's not your normal misfire and I suspected it could be fuel related but if it's fuel starvation wouldn't the AFR be leaning out before it got to the point of misfire? Do you know if fuel pressure can be read using Cipher or do I need to get hold of a gauge to plumb in? If I can read it with Cipher I can get it checked out at work tomorrow while it's quiet. Quote Link to comment Share on other sites More sharing options...
evilscorp Posted January 18, 2014 Share Posted January 18, 2014 Dirty maf ? If it's been leaking oil in the intake pipes? Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted January 18, 2014 Share Posted January 18, 2014 Dirty maf ? If it's been leaking oil in the intake pipes? Lol, did you read the thread? I assume you've done your seals due to burning oil? Have you cleaned the MAF since? but cleaned it today with a good dose of brake cleaner for good measure which hasn't seemed to help. Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 Thanks for the suggestion Evilscorp but I don't think that can be it. As I said I cleaned it today with no luck. It's also not something that has progressively got worse. It just started after I had everything apart so I'm guessing it must be something I've done or disturbed. Just wish I could figure out what! Having said that it was just sat on the driveway for about 3 weeks until I had the time to finish it so it's possible something could've failed or started sticking in that time. Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 (edited) Could it be something to do with the VVT? Does anyone know if the valve timing is continuously variable or does it switch at a set RPM? 4K perhaps?? Edited January 18, 2014 by theminiking Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 Its a non-revup 2004 btw. Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted January 18, 2014 Share Posted January 18, 2014 It does sound like fuel starvation as Darren suggested, this could be caused by quite a few things. Do you not have a fuel pressure gauge on your fuel pressure regulator? If I was you I would check the fuel pressure at idle first and make sure thats ok. I would remove the Vortech Cog belt, so you are essentially running as an N/A and go for a drive and see if it still does it, It should drive fine - you will then know if its boost or S/C related or not. Also, as you suspected your CAI before, I would remove it and put the filter directly onto the S/C inlet for now until you find the issue. With that in mind, is your Air filter clean? Out of interest, has it been wet out when you've been driving? Quote Link to comment Share on other sites More sharing options...
evilscorp Posted January 18, 2014 Share Posted January 18, 2014 I assume you've done your seals due to burning oil? Have you cleaned the MAF since? My bad lol on my mobile so sometimes miss a post with scrolling issues (embarrassed smiley) Quote Link to comment Share on other sites More sharing options...
evilscorp Posted January 18, 2014 Share Posted January 18, 2014 Since you aren't running deatchwerks injectors, they are probably not the problem (right Sam =) Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 No, I don't believe the FPR that came with the Vortech kit has a gauge. I'll have to get one on order. I'm afraid removing the CAI isn't an option as the original filter was collapsing under suction so it got binned. It's replacement is 3 times the size and won't fit directly onto the S/C anymore. I'm confident the CAI setup can't be causing any issues now and yes the filter is only about 1000 miles old and had a clean whilst I was cleaning all the intake pipework a few weeks ago. That's a good suggestion about removing the belt though. I suspect the map will be wildly out but it would definitely help narrow things down. I'll get it done tomorrow. Cheers for the advise! Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 18, 2014 Author Share Posted January 18, 2014 It's been driven mostly in the dry. 400bhp is a bit pointless in the wet! Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted January 18, 2014 Share Posted January 18, 2014 Can you show us a picture of your FPR? Or know what make it is? It's a bit unclear what you have. Most FPR that come with fuel return systems have gauges fitted. Or do you have the big blue one that comes with the vortech kit? Running your car as an na with the cog belt removed shouldn't be a problem as your map will be based around airflow though the MAF so if the sc isn't pushing air past it, it will fuel accordingly . I've done it many times and it drives fine, just like an na. Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 19, 2014 Author Share Posted January 19, 2014 It is the big blue Vortech one. Looks alot like this one from what I recall: http://www.vortechsuperchargers.com/page.php?id=30031 Its been on there since 2005/6 so may be a different model. I think I need to get underneath again and chase all the pipework with the Vortech installation manual in hand to see if there's anything amiss. Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted January 19, 2014 Share Posted January 19, 2014 Ok, so its the original Vortech FMU Item. Do you definitely have a proper Return fuel system with an additional fuel line going back to the tank and the Walbro (255)pump in the tank? Or do you have a walbro 155 fitted inline under the car near your FPR? Most people when fitting a return fuel system ditch the Vortech FMU and fit a proper rising rate FPR. I would check all the the vacuum / boost lines in the system, in particular the ones to the Vortech FMU and the Bypass valve as the ones under the car are prone to splitting and leaking, aslo check for kinks. Its quite likely the FMU isn't receiving the correct boost pressure and therefore not increasing your fuel pressure enough. Check the fuel connections for leaks also. Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 19, 2014 Author Share Posted January 19, 2014 Sorted! Whilst following all the fuel lines to figure out how is all plumbed in realised I have the additional 155lph Walbro pump at the front which is not what I thought was fitted. And it had no power to it. Followed the wiring back and there was a loose connection inside the pass thru grommet to the battery bay which I must have disturbed. Reconnected it and took it for spin and the beast is back! I'm really getting to know this car now. I'd like to spend a bit more time behind the wheel and less under the bonnet now though! Thanks very much for everyone's help, it's greatly appreciated. Laurie. 1 Quote Link to comment Share on other sites More sharing options...
Sam Mcgoo Posted January 19, 2014 Share Posted January 19, 2014 I thought that might have been your set up. Just out of interest, Are you sure your not running the SST box for tuning? It's normally located in the battery compartment. It's just that that;s what normally swtches on your Aux pump when it senses boost. Glad you've got it sorted. Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 19, 2014 Author Share Posted January 19, 2014 No, it's definitely running an uprev map. I've bought the cable and been out with my tuner doing the mapping runs. I'm not sure what turns on the additional pump though, I just assumed it would be running all the time the stock pump is. Quote Link to comment Share on other sites More sharing options...
gsexr Posted January 19, 2014 Share Posted January 19, 2014 Gotta luv this forum. All the help thats supplied is Quote Link to comment Share on other sites More sharing options...
theminiking Posted January 19, 2014 Author Share Posted January 19, 2014 Definitely! 👠Quote Link to comment Share on other sites More sharing options...
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