themodifiedkid Posted March 1, 2015 Share Posted March 1, 2015 Right here goes: I replaced the turbos and after which car wasn't boosting as it should so checked for vaccum/boost leaks and couldn't find anything obvious. Anyway to eliminate any VSV trouble I put the car in ttc mode. I've just taken the car out and I plant my foot down and boost hits 1.2 -1.3 for literally 2 seconds then drops down to about .8 and slowly drops to .6, I then kick down again and similar thing happens. I pulled over into a lay by and have a look if any pipes have popped off which they hadn't. So off I go again and this time the boost kind of stutters as it creeps up to 1 bar but it's fluctuating and the car is juddering!!! I ease right off and approached a junction, this is when I can hear and feel the car running really lumpy and juddering. So I make my way home slow as the car now feels gutless. I've pulled it into my garage to try and see what's happening but can see anything apart from a spray of what looks like coolant up towards the back of the engine near where the turbos are but no trace of where it has come from??? I then rev the car gentle which usually promotes the hks bov to sound but nothing, I pulled of one of the vacuum pipes to which realised a pressure build up in the system which is what it should do I'm guessing. I then put the pipe back on and gentle rev to which I then got the bov to sound. But the engine is still running really lumpy and juddery. My wide band Afr shows normal running of between 14.7 - 15.1 and when on heavy boost it was in the low 10s. Does anybody know or have any idea as to what has happened. Is my engine knackered? Or could there be a simple explanation to this. Any help would be greatly appreciated. It's a auto bpu with all the supporting mods Thanks Quote Link to comment Share on other sites More sharing options...
The Raven Posted March 1, 2015 Share Posted March 1, 2015 I dont think your engine is shot mate, you didnt do anything to it. Turbo seals? Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted March 1, 2015 Share Posted March 1, 2015 Not an expert, but if its not boosting properly in TTC, there is a vac hose leaking somewhere or the pressure tank is at fault... Quote Link to comment Share on other sites More sharing options...
themodifiedkid Posted March 1, 2015 Author Share Posted March 1, 2015 I dont think your engine is shot mate, you didnt do anything to it. Turbo seals? Pretty sure it's not turbo seals as there's no smoke from exhaust!! Quote Link to comment Share on other sites More sharing options...
themodifiedkid Posted March 1, 2015 Author Share Posted March 1, 2015 Not an expert, but if its not boosting properly in TTC, there is a vac hose leaking somewhere or the pressure tank is at fault... When I pulled off a vaccum hose there was a whoosh of air which I thought would indicate the system is holding pressure. What I can't work out is why the engine is running really lumpy( I suppose misfiring) would a problem turbo side cause this to happen? Quote Link to comment Share on other sites More sharing options...
The Raven Posted March 1, 2015 Share Posted March 1, 2015 http://www.mkivsupra.net/vbb/showthread.php?35926-The-sequential-system Glad there is no smoke Quote Link to comment Share on other sites More sharing options...
The Raven Posted March 1, 2015 Share Posted March 1, 2015 (edited) http://mkivsupras.com/vbb/showthread.php?1320-Unknown-boost-pressure-drop Edited March 1, 2015 by The Raven (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted March 1, 2015 Share Posted March 1, 2015 Sounds like a boost leak. The symptoms definitely point that way. Most likely cause is an intercooler pipe popped off somewhere. it could also be the rubbers between the upper turbo pipes. They collapse inside and it's hard to notice them. Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 1, 2015 Share Posted March 1, 2015 Sounds like an intercooler or pipe has come away, Do you have a stock intercooler or front mount, regardless I would check the intercooler piping Quote Link to comment Share on other sites More sharing options...
themodifiedkid Posted March 1, 2015 Author Share Posted March 1, 2015 I checked all intercooler hoses and relevant hoses and all are tight. And the upper hoses have been replaced. I just done understand that engine was idling/ running smoothly then take it for a blast then idles and runs like a bag of crap!!! Frustrating isn't the word QUOTE=Scott;3998854]Sounds like a boost leak. The symptoms definitely point that way. Most likely cause is an intercooler pipe popped off somewhere. it could also be the rubbers between the upper turbo pipes. They collapse inside and it's hard to notice them. Quote Link to comment Share on other sites More sharing options...
Scott Posted March 1, 2015 Share Posted March 1, 2015 What you describe is exactly what would happen with a boost leak. You need to be 100% certain on every pipe and every join. A split silicone coupler out of view would do the same. Quote Link to comment Share on other sites More sharing options...
themodifiedkid Posted March 1, 2015 Author Share Posted March 1, 2015 What you describe is exactly what would happen with a boost leak. You need to be 100% certain on every pipe and every join. A split silicone coupler out of view would do the same. Ok cheers mate. Think what I'll do is strip everything down ( boost pipes etc, check them all thoroughly and replace) I can't work out where the spray of coolant came from. I suppose I'll find out when stripping it down Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted March 1, 2015 Share Posted March 1, 2015 (edited) Are the turbo pressure sensor and fuel pressure regulator vac lines intact? Do you have a boost cut? I remember I had the wire pull out while driving, car went lumpy.. ECU light was on though Edited March 1, 2015 by Samurai 20V (see edit history) Quote Link to comment Share on other sites More sharing options...
themodifiedkid Posted March 1, 2015 Author Share Posted March 1, 2015 Are the turbo pressure sensor and fuel pressure regulator vac lines intact? Do you have a boost cut? I remember I had the wire pull out while driving, car went lumpy.. ECU light was on though I've just checked the pressure sensor and regulator vac lines and are all intact. And no boost cut. Also no stored error codes!! Quote Link to comment Share on other sites More sharing options...
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