Fueling issue new install
Just installed a 70050 500hp kit on my 5.3 with BTR stage 3 cam. The initial startup went well but everything went to crap on the first heat up cycle. I noticed the ebay Walboro pump only had about 40 psi and would sometimes drop to zero, yet the car would still idle. Then the misfires started.. They turned out to be burnt plug wires due to contact with exhaust headers even with the heat boots on them. I changed the plugs and the wires and installed a new Aeromotive 340 Series in tank pump. I'm using a Corvette 58 psi regulator/filter. The issue now is the car runs extremely rich (smokes out my garage) the car cranks and fires but then stumbles and stalls unless the throttle blade is held open a little, fuel pressure at key on builds to 58 then kicks off, fuel pressure when idling (with someone holding the throttle open slightly) is in the 60s. If I disconnect the fuel pump 12v supply voltage then start the car it will start and run for a number of minutes, I didnt time it but at least 2 minutes until I turned the key off. Not sure how this works, siphoning fuel sometime? I tried reloading the default tune, other cam 1-4 selections, turning the prime shot all the way down along with all other fuel related items, I quadruple checked all grounds and positive connections ensuring they went to the battery as well. I've also tried running the car with a battery charger on with no change. Checked exhaust connections for leaks... I was going to call Fitech about maybe the corrupt files or ecu but wanted to try reloading the software first, anyone have the software download link or can shed more light on this?
What are your AFR readings? Do you have one or two o2 sensors (two is better)?
Those fuel filter/regulators are notoriously inaccurate, I've heard that the genuine ACDelco version is better.
I'd suggest you change to a proper fuel pressure regulator.
Stay away from Fitech (or even Holley) fuel components, look to Aeromotive or Fuel tech. Use a good fuel filter just before the fuel rail, like a 15 micron tube.
Another thing, never run a fuel injected system while connected to a battery charger.
Thanks for the reply. This kit has just the one wideband and I haven't considered looking at afr yet as it is so rich. The Corvette regulator has a 10 micron filter contained within it. I was looking at the Aeromotive adjustable setup but wanted to try and save some money, probably should have got it anyway. I'll probably order it anyway but was out of ideas on why this has turned south so quickly.
I found one of the culprits to be a cracked map sensor, not sure how that happened but the reading was off the charts on the handheld. I got a new one and it fires right up. I also installed a new Aeromotive pump with an adjustable fpr an an inline filter. It starts and runs great cold but I've ran into a hot no start issue. I think the injectors aren't firing. The afr is high 17-20s so no fuel. When it cools to around 160ish it will fire up again and run fine. I ordered a one-way check valve to put inline to try to help. Battery voltage is 12 volts usually, if I put it on a charger for awhile and try to start it while it's still hot I still have a not start condition. I tried upping the Prime shot to 100 and crank fuel to 50 but it had zero change. Fuel line seems warm but not excessively hot like a vapor lock issue.. Any ideas?
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I had similar hot start issues and found that the system was loosing pressure when the key was off. I replaced the fuel pressure regulator with a Fitech one. That solved the initial fuel bleed down issue, but not completely, so I added a check valve between the fuel filter and the fuel rail. That solved the bleed down issue. The fuel pressure holds at 30 PSI for several days so far.
Adjusting the Fitech fuel pressure regulator was difficult. I initially used the key on to set the pressure but would never reach 58 PSI. Started the engine anyway and pressure was at 65. Engine ran rich until I lowered the pressure to 58. The gauge would not respond while the engine was running so I had to make adjustments while the key was off. Engine starts much quicker now that the pressure does not bleed down.
I made a lot of changes to the Crank and Warmup settings to try an solve the hot start issue. I have since reversed those back to the settings I started with like the Prime Shot is back to 14 from 12.
Finally FiTech sent an email today informing me that the fuel pressure gauge would not respond to changes made to the adjustment screw. Only a few days late with their response.