Ian C Posted May 13, 2013 Share Posted May 13, 2013 It doesn't look like a quick one to diagnose now I'd start by checking the injector duty cycles and fuel mix at that point. Ignition timing as well, seems almost like it's retarding a lot there. Also, try any other diagnostics to try and pick up on things that aren't right - intake temp sensor, TPS readings, lots of stuff like that. Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 13, 2013 Author Share Posted May 13, 2013 Thanks Ian, will try to check other stuff. Don't know if it helps, but it has always started OK when cold, but when warm, it needs the second attempt. First attempt takes forever(if at all), but second attempt is almost instant success. Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 13, 2013 Share Posted May 13, 2013 Thanks Ian, will try to check other stuff. Don't know if it helps, but it has always started OK when cold, but when warm, it needs the second attempt. First attempt takes forever(if at all), but second attempt is almost instant success. Thats because the piggy back ecu , almost everyone with a piggy has this issue Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 13, 2013 Share Posted May 13, 2013 I've got that mystery start issue, although when just keyed off it start fine, it's after juuuust enough time to fill the sodding thing with fuel it then embarasses you. FYI, as soon as it start doing the "I'm not going to play ball" turnover behaviour, you can stop, key completely off, wait 30 seconds and then try again. You don't have to keep trying on the first attempt once it gets a cob on. My progress is slow on further diagnosis but I get the feeling it might help more than just me out so I'll make sure I keep digging away at it Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 14, 2013 Share Posted May 14, 2013 I've got that mystery start issue, although when just keyed off it start fine, it's after juuuust enough time to fill the sodding thing with fuel it then embarasses you. FYI, as soon as it start doing the "I'm not going to play ball" turnover behaviour, you can stop, key completely off, wait 30 seconds and then try again. You don't have to keep trying on the first attempt once it gets a cob on. My progress is slow on further diagnosis but I get the feeling it might help more than just me out so I'll make sure I keep digging away at it ian im starting to think its related to , open / closed loop starting when cold its open loop starting making for a nice rich start but when hot/warm its then closed loop starting with timing pulled and lean start (stock ecu) due to intake temp sensor heat soak,this only starts after the long cranking getting fuel into the cylinder and second attempt. i can always get mine to start when warm if i put loads of fuel in my map at cranking speed, but when cold cranking is very rich. also i have found that when it happens if you just plant you foot on the throttle before and while your trying to start it will normally catch first time (not first turn over but first time trying a few cranks latter) Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 14, 2013 Author Share Posted May 14, 2013 (edited) Just checked the TPS, seems to operate perfectly fine. Closed = 0.6 kOhm Fully open = 3.7 kOhm. also no strange behaviour in between, seems to run pretty linear. idle switch Edited May 14, 2013 by DJT88 typo (see edit history) Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 14, 2013 Author Share Posted May 14, 2013 Reading up on some stuff today... Could it be bad Knock Sensors or bad wiring of knock sensors?? Since they somewhat control (retarding) ignition timing. Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 27, 2013 Author Share Posted May 27, 2013 Just an update. I'm still on this, just to rule out some things I bought a new walbro 255 fuel pump and new filter. And to make some bits more shiny a smic hard pipe kit from whifbits. Will install the stuff this week, so we'll see how she goes after this. Will check the wiring on the knock sensors as well while I'm installing the pipe kit. Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 30, 2013 Author Share Posted May 30, 2013 Alright, a great update on this issue. I'm 99% confident I've fixed the problem. I've installed the Walbro 341 (255 lph) fuel pump. Went out for a test drive and voilla! Perfect boost, perfect revving when stationary. Feels alot stronger and even starts excellent when warm (so no piggyback starting issue for me there). Can't be any more happy now!! :D:D:wooohoo: Quote Link to comment Share on other sites More sharing options...
jcbt Posted May 30, 2013 Share Posted May 30, 2013 Alright, a great update on this issue. I'm 99% confident I've fixed the problem. I've installed the Walbro 341 (255 lph) fuel pump. Went out for a test drive and voilla! Perfect boost, perfect revving when stationary. Feels alot stronger and even starts excellent when warm (so no piggyback starting issue for me there). Can't be any more happy now!! :D:D:wooohoo: Good news glad you fixed it Bud Quote Link to comment Share on other sites More sharing options...
Littler Posted May 30, 2013 Share Posted May 30, 2013 Good news! Just a question you weren't running full bpu boost on the stock fuel pump originally were you? Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 30, 2013 Author Share Posted May 30, 2013 (edited) Good news! Just a question you weren't running full bpu boost on the stock fuel pump originally were you? Originally when I bought it, it was running 1.0 bar with stock SMIC and stock Exhaust system. However I've upgraded to Catback and CW SMIC. I'm thinking the increase in load for the pump has worn it out maybe, which caused my intermittent problems. However, when changing the pump I discovered that the original j-spec pump was already out. It was fitted with some sort of nissan R32 GTR pump. (supposedly 195 lph) old pump & new walbro: Unisia jecs A42-621B70 12V 1910 Made in Japan Edited May 30, 2013 by DJT88 (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 30, 2013 Share Posted May 30, 2013 nice so it probably was knock sensors where you was running lean maybe Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 30, 2013 Author Share Posted May 30, 2013 nice so it probably was knock sensors where you was running lean maybe probably yeah, so they work For future reference: This was how the old fuel pump was 'installed'. Not very tidy at all and the fuel hose had a tight curve in it to connect to the line. You can see it had split the outer rubber layer exposing the braided stuff underneath. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 30, 2013 Share Posted May 30, 2013 The wiring looks a bit tight as well. Quote Link to comment Share on other sites More sharing options...
DJT88 Posted May 31, 2013 Author Share Posted May 31, 2013 The wiring looks a bit tight as well. yeah, wasn't very well done at all... This is how I fixed it. https://dl.dropboxusercontent.com/u/3472574/fuel_pump_walbro.JPG Quote Link to comment Share on other sites More sharing options...
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