Milo500 Posted September 23, 2018 Share Posted September 23, 2018 Hi guys, I have an ongoing problem, that has been happening for a while. The car is a single turbo from twin, auto non vvti 1993. It was making 485hp at the crank for well over a year, and never let me down...however due to all the issues I have faced in the last year or so, it's really starting to piss me off haha. (I converted it myself to single about 3 years ago). So in a nutshell, this time last year the original gearbox started to go, so I bought one from a low mileage aristo, had it shimmed by David p and put I back in with a precision 3200rpm high stall. At the same time, I had two changed the boost controller from a greddy profec to an LD Performance one (the profec screen smashed and was advised to get the new LD one (including solenoid). After the gearbox and BC change, it felt like there was a low rev limiter at around 4.5k...the coil packs and connectors were changed, and that was solved. Then the surge started. The problem is, since all of this, on full boost (1.5 bar, yes it was properly mapped before and ran perfectly), it now turbo surges at 1.5bar, or anything over 1.2bar. It also runs very rich, around 10.0-10.6 afr when full throttle (driving normally it runs fine). And it due to this it feels like it is down on power to the 300hp mark. Trying to find out, and solve this issue, the following has been done. Plugs changed and gapped Coils packs changed Coil pack connectors Various small boost leaks sorted Wastegate changed and gasket Exhaust manifold skimmed Exhaust manifold gasket Turbo t4 gasket All vacuum lined Intake gaskets Throttle body gasket Intercooler swapped to make sure original wasn't leaking (There are no boost leaks, for certain) Boost controller Gearbox (aristo and shimmed) Gearbox filter and oil +stop slip Torque converter Compression test (all around 150 psi, 133k I'm mileage) Nothing has changed...I am now at a complete loss...pretty much everything has been done apart from rebuilding the motor haha... Any help would be hugely appreciated. I'll happily update on anything I may have missed. Thanks Link to comment Share on other sites More sharing options...
j_jza80 Posted September 23, 2018 Share Posted September 23, 2018 No mention of your current ECU? Link to comment Share on other sites More sharing options...
Milo500 Posted September 24, 2018 Author Share Posted September 24, 2018 Sorry, it is a greddy emanage blue piggyback. Completely different unrelated problem...It is now knocking...brilliant, however, I'm not sure if it is bottom end. It seems to happen only for a few seconds at a certain vibration on start up, but runs perfect any other time Link to comment Share on other sites More sharing options...
Swampy442 Posted September 24, 2018 Share Posted September 24, 2018 Gotta say its possibly the ECU, have you checked it out? I had an manage ultimate go bad years ago and cost me my engine. Emanage blue are so old and shit nowadays, get a Link or syvecs or something, why go single and scrimp on the most important part of the job? Link to comment Share on other sites More sharing options...
j_jza80 Posted September 24, 2018 Share Posted September 24, 2018 Was the emanage remapped when you fitted your new gearbox? Its a bit beyond my knowledge, but the way that high stall torque converters and shimmed boxes work, they change the way the engine comes under load, thereby increasing low rpm spool, which would require additional fuelling to prevent running lean earlier in the engines rpm range. A skimmed exhaust manifold would also have an impact (albeit, I suspect a very minor one), and things like your intercooler and wastegate too, unless changed for exactly the same items. Link to comment Share on other sites More sharing options...
Milo500 Posted September 25, 2018 Author Share Posted September 25, 2018 Was the emanage remapped when you fitted your new gearbox? Its a bit beyond my knowledge, but the way that high stall torque converters and shimmed boxes work, they change the way the engine comes under load, thereby increasing low rpm spool, which would require additional fuelling to prevent running lean earlier in the engines rpm range. A skimmed exhaust manifold would also have an impact (albeit, I suspect a very minor one), and things like your intercooler and wastegate too, unless changed for exactly the same items. It hasn't however, the torque converter gets locked, or "stalled" when on the dyno, so wouldn't make a difference bud, but I get what you are saying. All the boost leaks and manifold make sense also, however it runs rich, not lean, which doesn't make sense haha...Is doing my head in this car. Link to comment Share on other sites More sharing options...
Milo500 Posted September 25, 2018 Author Share Posted September 25, 2018 Gotta say its possibly the ECU, have you checked it out? I had an manage ultimate go bad years ago and cost me my engine. Emanage blue are so old and $#@! nowadays, get a Link or syvecs or something, why go single and scrimp on the most important part of the job? Because i don't have a spare few k's to throw at an ecu and mapping at the moment bud. Link to comment Share on other sites More sharing options...
Swampy442 Posted September 25, 2018 Share Posted September 25, 2018 Id still get the ECU map checked at least, you can pull data logs I think Link to comment Share on other sites More sharing options...
j_jza80 Posted September 25, 2018 Share Posted September 25, 2018 Does it run rich all the way through the rpm range? Link to comment Share on other sites More sharing options...
Milo500 Posted September 26, 2018 Author Share Posted September 26, 2018 Does it run rich all the way through the rpm range? Runs perfect, apart from on full throttle...it then runs rich, like 10.0-1 afr Link to comment Share on other sites More sharing options...
j_jza80 Posted September 26, 2018 Share Posted September 26, 2018 Define what you're describing as surge. Are you talking about this kind of sound? Link to comment Share on other sites More sharing options...
j_jza80 Posted September 26, 2018 Share Posted September 26, 2018 Also, I assume you have a pretty free flowing exhaust fitted? Link to comment Share on other sites More sharing options...
Milo500 Posted September 27, 2018 Author Share Posted September 27, 2018 Also, I assume you have a pretty free flowing exhaust fitted? Yepp, is a complete 3" straight pipe from the turbo back. Is definately surge, sounds like a slightly qieter flutter, but when on boost, not letting off. Link to comment Share on other sites More sharing options...
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