CrayZ Posted January 21, 2013 Share Posted January 21, 2013 (edited) I would like to run a tune on my lq4. Been looking at HPtuners but I really don't want to spend extra money to have someone unlock my PCM. Can EFI live tuners work the PCM without having to buy credits to unlock the pcm? Anyone in houston area tune there own car? I'm looking for options local to me first but don't mind sending off my PCM to get worked. Anyone have any good info on this? I'm getting a hard start and what sounds like fuel in the exhuast on startup. Hoping a better tune can sort this out for me. Edited January 21, 2013 by CrayZ Quote Link to comment Share on other sites More sharing options...
Mikey303LSZ Posted January 22, 2013 Share Posted January 22, 2013 I can't speak for EFI Live but... I bought HP Tuners a year ago and the program comes w/ enough credit to plug into 3 or 4 GM vehicles (perhaps less for something other than GM). Once credit is applied to a vehicle you have unlimited access to the vehicle. There are tons of pre-made HP Tunes on the HP Tuners board (run at your own risk). I've been super happy with the program and it saved my brother in-law $150 the price of tuning at a local dyno shop when using my HP Tuners "Dongle" and passcode. The data logging feature is really nice and makes it easy to troubleshoot problems that occur during drivabilty and WOT runs. I'm also using it on my Datsun to disable the rear O2s, the VATS etc. and tune/dial-in the motor/auto-trans. If someone didn't want to drop the $650 for unlimited access to multiple cars I would suggest going to a local tuner and paying them to troubleshoot/repair the issue (this route might cost $250 to $500). Quote Link to comment Share on other sites More sharing options...
sq_creations Posted January 29, 2013 Share Posted January 29, 2013 I believe both programs are credit based. I use Hp tuners on numerous vehicles and I am very happy with the program. Compared to others I have dealt with HP is organized and easy to navigate. I haven't tried EFI live yet though. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 29, 2013 Author Share Posted January 29, 2013 Local big shot tuner here in houston quoted me $500 for a full work dyno tune and $75 for any adjustments after that. Might just got that route seeing as my knowledge on tunning is VERY minimal Quote Link to comment Share on other sites More sharing options...
rags Posted January 30, 2013 Share Posted January 30, 2013 I use EFI Live and it it is also credit based. Joe Quote Link to comment Share on other sites More sharing options...
mattd428 Posted February 2, 2013 Share Posted February 2, 2013 My tuner in fort worth is $200 for a tune but with fuel in the exhaust from a cold start you sure you dont have leaky injectors? I had an injector stick open fill a cylinder with gas which ended up snapping a rod the next time i started it. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 2, 2013 Author Share Posted February 2, 2013 My tuner in fort worth is $200 for a tune but with fuel in the exhaust from a cold start you sure you dont have leaky injectors? I had an injector stick open fill a cylinder with gas which ended up snapping a rod the next time i started it. Hydro lock.. Man that scares the shit out of me. How can you check for leaky injectors? Quote Link to comment Share on other sites More sharing options...
mattd428 Posted February 3, 2013 Share Posted February 3, 2013 Take the injectors out fill them with brake cleaner and blow through them or take the intake off leave the fuel rail and injectors mounted but remove the electrical connectors and charge the fuel system. If you see gas theres a problem. Quote Link to comment Share on other sites More sharing options...
Mikey303LSZ Posted February 5, 2013 Share Posted February 5, 2013 Another way to check for leaky injectors is to perform a leak down test by installing a fuel pressure gage onto the schrader valve located at the front of the LH fuel rail (assuming stock fuel rail). Turn the key on to build pressure (values that come to mind are ~50-60lbs) then turn the key off. The owners manual has a spec. for the pressure and duration the system should hold pressure/bleed down. If it bleeds down quick additional diagnostics would be required to determine where the leak is coming from (fuel lines, check valve, regulator, injector etc.). Pressure will slowly bleed down when everything is ok, but it takes anywhere from an hour to 3 or 4 hours to do so. If after 15 or 30 minutes all your pressure has bleed off you have a problem. A leaky injector should/could throw a code that could be read from the PCM (one bank or perhaps both running rich). You can also check for leaking injectors by unbolting the fuel rail and pulling the rail with injectors out of the intake so you can see the ends of the injectors. Do a key on prime and watch for injectors that are leaking fuel . If they don't leak within a few minutes, check every 10 minutes or so for about and hour to make sure. Also have a fuel pressure gage on the schrader valve to see how fast pressure is bleeding down. Good luck... Quote Link to comment Share on other sites More sharing options...
mattd428 Posted February 5, 2013 Share Posted February 5, 2013 Another way to check for leaky injectors is to perform a leak down test by installing a fuel pressure gage onto the schrader valve located at the front of the LH fuel rail (assuming stock fuel rail). Turn the key on to build pressure (values that come to mind are ~50-60lbs) then turn the key off. The owners manual has a spec. for the pressure and duration the system should hold pressure/bleed down. If it bleeds down quick additional diagnostics would be required to determine where the leak is coming from (fuel lines, check valve, regulator, injector etc.). Pressure will slowly bleed down when everything is ok, but it takes anywhere from an hour to 3 or 4 hours to do so. If after 15 or 30 minutes all your pressure has bleed off you have a problem. A leaky injector should/could throw a code that could be read from the PCM (one bank or perhaps both running rich). You can also check for leaking injectors by unbolting the fuel rail and pulling the rail with injectors out of the intake so you can see the ends of the injectors. Do a key on prime and watch for injectors that are leaking fuel . If they don't leak within a few minutes, check every 10 minutes or so for about and hour to make sure. Also have a fuel pressure gage on the schrader valve to see how fast pressure is bleeding down. Good luck... what he said^^^^ Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 7, 2013 Author Share Posted February 7, 2013 I have an aftermarket FPR and when I cycle the key it jumps to 50 or so and within 20 seconds settles down to 20 psi. I'm pretty sure the injectors are leaking. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 7, 2013 Author Share Posted February 7, 2013 Can a simple o ring change fix this or is it an internal issue in the injector? Quote Link to comment Share on other sites More sharing options...
Mikey303LSZ Posted February 7, 2013 Share Posted February 7, 2013 Regarding o-rings... There are two o-rings per injector. The lower one has nothing to do with a fuel leak issue. The upper one (interface between the injector and fuel rail) could be leaking but if they were you most likely would see/detect/smell a fuel leak at the top of the injector (without removing anything). I got thinking... an OEM/factory fuel injection setup will have a check valve located in the system (typically located in the in-tank fuel pump). This is done to maintain system pressure to ensure quick start-up w/o excessive key-on prime delay. Depending on your fuel pump/regulator selection your system may not hold pressure therefore the OEM/stock way of monitoring pressure at key off (as mentioned above) may not be valid for your vehicle. In other words... Try pulling the injectors out of the intake manifold (as mentioned in the post above) to determine if any of the injectors are leaking. Good luck! Let us know how it goes. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 7, 2013 Author Share Posted February 7, 2013 Will do, thanks Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 7, 2013 Author Share Posted February 7, 2013 I am running dual external Walboro pumps (just thought about that) so I don't think the in tank check valve applies to my situation but I will get it taken apart to see what it does Quote Link to comment Share on other sites More sharing options...
mattd428 Posted February 8, 2013 Share Posted February 8, 2013 I agree could still bleed off would be better off pulling the injectors to test them. If it was an oring you would see a leak and most likely smell it at the top of the injectors. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 8, 2013 Author Share Posted February 8, 2013 Well i pulled the rail off, injectors attached and cycled the key. It kept blowing injectors out of the rail.. So that idea is out the window Quote Link to comment Share on other sites More sharing options...
mattd428 Posted February 8, 2013 Share Posted February 8, 2013 (edited) lol ya you cant do that take each injector and literally blow through them if you can blow through it it leaks or take the intake off with the fuel system attached but no electrical connectors on the injectors and cycle the key Edited February 8, 2013 by mattd428 Quote Link to comment Share on other sites More sharing options...
rags Posted February 8, 2013 Share Posted February 8, 2013 2 tie wraps on each injector in a crisscross pattern will hold them in the rail when the rail is not bolted to the intake manifold. I'm about 99% sure the drop in pressure is fuel going back to the tank via the fuel pumps. Joe Quote Link to comment Share on other sites More sharing options...
CrayZ Posted February 8, 2013 Author Share Posted February 8, 2013 Tie straps seem like a good idea. I agree with the drop in fuel pressure theory. I can't see a leaky injector dropping the fuel pressure over 30psi. Ill be out of town this weekend but will report back with my findings ASAP Quote Link to comment Share on other sites More sharing options...
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