little num Posted November 14, 2011 Share Posted November 14, 2011 Basically since having my engine back from the builders i have since fitted a fuel pressure reg on the return and on turning the engine over it shows around 35psi. But the car just turns over and over it does somtimes try and fire up but dont actually start. So i park on a drive and can bump it within 6 foot of rolling (2nd turn of engine on bump) once started it does start again no problems. Ive tried turning the FPR down to 20psi and upto 40psi but makes no diference at all. Battery is fully charged and turns over really quick. Plugs are NGK - BKR7E and gapped to 0.7 and dont smoke black when it does actually fire up by being bumped, little bit lumpy perhaps but drives ok. Any ideas guys - girls ???? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 14, 2011 Share Posted November 14, 2011 Measure the injector voltage and the ignition coil voltages when cranking? Bad earth? Tired battery? Bad map? The map itself is pretty much reliant on a known and stable fuel pressure, turning it up and down is a bit risky, unless you know you can return it to EXACTLY the pressure it was mapped at. Quote Link to comment Share on other sites More sharing options...
little num Posted November 14, 2011 Author Share Posted November 14, 2011 Ecu is a stock unit so havent a clue what the stock FPR was pushing out, Battery is brand new and a very large 1 fitted in boot. So if the fuel pressure wasent correct would that cause it to not fire on key but start within 6 foot of rolling and a bump. Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted November 14, 2011 Share Posted November 14, 2011 Have you checked for a spark while cranking James? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 14, 2011 Share Posted November 14, 2011 Check that the ecu ground eyelet tags are secured to the inlet manifold runners ground poit. It's very hard to see, let me know if you need help locating it. Low or high fuel pressure may make it harder to start, but would have to be probably over 20% too high, more likely if it's too low. Quote Link to comment Share on other sites More sharing options...
little num Posted November 14, 2011 Author Share Posted November 14, 2011 Hmmm lol ok ecu eyelet tags ???? i did take the full loom off the engine so maybe disturbed somthing. Do you have a image or somthing i can try and locate, i will add some earth cable on tomorrow (extra ones to make sure) and see what happens. Quote Link to comment Share on other sites More sharing options...
little num Posted November 14, 2011 Author Share Posted November 14, 2011 Yes ive had the coil packs out with spark plugs in them and they all seem to spark well so really strange, but as for it to start on a bump makes it even stranger. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 14, 2011 Share Posted November 14, 2011 http://www.mkivsupra.net/vbb/showthread.php?255027-Its-ALIVE..well-sort-of&highlight=eyelet Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.