Ok, there was nothing wrong with my car before. IT ran fine just a little stubble coming off boost cause i have 1600 secondaries and 550cc primaries.



I decide to use my spare 720cc injectors in the primaries location to help on the transition.



Well after installing them. Great car runs rich as hell. NO problem, i have haltech e6k. Tune them down, idles beautiful, better from the 550cc. Rides find on vacuum. But as soon as i hit boost the thing goes lean on me, pings, when it goes on boost that's where the 1600 kick in.



I'm scratching my head now. https://www.nopistons.com/forums/pub...1047683561.gif Bigger injectors should run rich more. The thing goes lean very lean. 14 afr. ping ping.



OK here is my settup.

HALTECH E6K, WALBRO 255HP PUMP, K2RD SECONDARY RAIL, 1600CC SECONDARIES, 720CC PRIMARIES, STOCK FPR.



My thoughts are,

1. the primaries are too big for the setiup i have, fuel pump can't provided enougth flow and pressure when all 4 injectors kick in.



2. Stock fuel pressure regulator not able to compensate, it is a year old.



3. I didn't not plug in the eletrical plugs all the way in to make good contact on the injectors.



4. I pinched a wire to the fuel injector harness.



5. Put back 550cc primaires and test.





Tonight i'm going to take out the upper manifold and check the connectors and vacumm hose to the FPR. Test the car again



Any other ideas?



C

Give car to me https://www.nopistons.com/forums/pub...>/rolleyes.gif

I think you're on track with your thoughts... not much to add. Other than maybe you should add a fuel pressure gauge so you can see whats going on when the secondaries come on. A flow meter on the return line could be useful, if theres little/no flow in the return line then your pump isnt up to the task.

were the spare 720s clean..

Thanks guys,



720 were like used for a year, bougth them new. They were my secondaries before the 1600 upgrade, they are also low impedence, the 1600 are high but that shouldnt' really matter.



Good thought. I stored them really good and lubed them before installing. Car idles great and response is good. Only when i apply a large load like going to boost like 1 or 2 psi it will stubble and ping.



I have a wideband 02 so i'm sure of the readings.



I'm goign to try some stuf tommorow. if no good. i'm putting back the 550cc and try again.



C

BJ i'm going to be up early tommorow and work on the car at Julio's garage in LB. I'm going to aim for 6am. lol but will. Maybe you want to stop by. I don't have to work till 4pm



C

what fuel pump are you running?



I would check the connections on the secondary injectors and make sure they are both working.

Well what do you need our help for, seems you have every possiblity. https://www.nopistons.com/forums/pub...#>/biggrin.png I would definalty get a fuel pressure gauge and aftermarket regulator while ur at it.

Just looking for your inputs. Leave no stone unturned. I will check the secondaries too. I didnt' touch them but you'll never know.





If swapping the 550cc fixes the problem. I will get a FPR. The fuel pump is a high pressure Walbro 255

C

he is not maxing out the fuel pump boostn7 made 400rwhp on the same pump....



i think either a fuel injector is faulty or something is not hooked up all the way.



if anything atleast you can just swap back to the 550's. this is why i haven't played with my car lately and just drove it less headaches https://www.nopistons.com/forums/pub...IR#>/blink.png