PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Cold starting problem

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Old May 24, 2017 | 08:19 AM
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Default Cold starting problem

Hey guys, let me first say I don't post very often, I search and search first. Let me start with a run down on what I'm working with. Im doing an ls swap into a 91 z28. It's my first so it's learn as I go. It's a 408 twin turbo, 80lb siemens injectors, trunk intake and throttle body, converted to 3 bar custom os. At this point , once the car starts, it's very responsive, revs good, and I'm getting the idle straightened away. But starting, the thing cranks and cranks, takes minutes to get it started. I'm thinking the pcm is going into clear flood. My tps is reading 100% with the key on not running and my iac counts are really high. Once started, the tps drops to between 70 and 80%. I've tried the tps reset , many times, doesn't change. I sprayed fuel past the throttle body and it fires up instantly. Any help would be greatly appreciated. Thanks
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Old May 24, 2017 | 11:29 AM
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What's your fuel pressure when it cranks?
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Old May 24, 2017 | 06:33 PM
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Got the pressure set on 60 psi at the rails. Running a return type system with 2 aeromotive 340 lph in tank pumps.
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Old May 27, 2017 | 11:07 AM
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How do u get idle straight out if tps at 70% u probably need to do some testing with your tps sensor
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Old May 28, 2017 | 03:08 PM
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Not jumping the gun and saying I got it fixed, but I think it's my ecm. I guess the car would idle because it was in limp mode or something. Didn't sam it was smooth, doughty it ever will be, got a bar stage 3 turbo cam. I messed with the hptuners scanner, tried to reset the tps. Nothing. grabbed the spare 411 I had and plugged it in, had .5 volts with the key on. Flashed the 3 bar file to it, started right up. I'll keep my fingers crossed on this one.
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Old May 28, 2017 | 10:32 PM
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glad u got it sort it out
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