FredB66
Member
I just finished installing a Brenspeed Vortech V3-Si non-intercooled system on my 2007 GT and would appreciate some help troubleshooting a no-start. The engine was completely stock and the install went fairly well. I did do some additional stuff while I had it apart and installed a new alternator, water pump, coil packs, and new OEM 55mm TB. I had the valve covers off to paint and the intake manifold off to install the IAT sensor relocation kit. The only misstep I can think of is forgetting change the fuel pump fuse (#41) from 15A to 30A for the included a Vortech Maxflow BAP. The fuse blew the first time I tried to start so I changed it. I subsequently ditched the BAP and stock FP in favor of a Walbro FP.
Turning the key on, the FP primes and when I try to start it cranks, stumbles for a brief second and that's it. Try again and then it just turns over with nothing. Part by part I've been returning the car to its original state with no change. The TB, coil packs, plugs and the tune have been brought back to original. I pulled the intake to see if perhaps I pinched a wire somewhere. I've got 12.3V at the FP connector with the key on and Forscan reporting 75 psi at the rail and then varying down to around 45 when cranking. Is that normal? If so, I think that checks out the fuse, relay, inertial cutoff, FPDM, and FP circuit. At Brenspeed's suggestion, I've tried disconnecting the MAF and the fuel rail pressure sensor. I've checked spark at a few different coils and it looks good. No DTC's reported. I just got Forscan this weekend so I'm still learning how to use it.
I've been fighting this for over a week and getting nowhere. The engine is essentially back to original except the 39 lb injectors, the Vortech compressor and the Walbro FP. Through the course of the install I touched a lot of wire and connectors so I've been checking everything I can think of looking for something loose or broken. Brenspeed hasn't offered much help though I do understand that its likely not their stuff that's the problem. I spent a long while on the phone with SCT trying to verify that the stock and custom tunes didn't get get jacked up somehow. Everything supposedly checks out tune-wise. Probably a long shot but I had to check the box. So, I'm running out of ideas. Any suggestions would be greatly appreciated.
Turning the key on, the FP primes and when I try to start it cranks, stumbles for a brief second and that's it. Try again and then it just turns over with nothing. Part by part I've been returning the car to its original state with no change. The TB, coil packs, plugs and the tune have been brought back to original. I pulled the intake to see if perhaps I pinched a wire somewhere. I've got 12.3V at the FP connector with the key on and Forscan reporting 75 psi at the rail and then varying down to around 45 when cranking. Is that normal? If so, I think that checks out the fuse, relay, inertial cutoff, FPDM, and FP circuit. At Brenspeed's suggestion, I've tried disconnecting the MAF and the fuel rail pressure sensor. I've checked spark at a few different coils and it looks good. No DTC's reported. I just got Forscan this weekend so I'm still learning how to use it.
I've been fighting this for over a week and getting nowhere. The engine is essentially back to original except the 39 lb injectors, the Vortech compressor and the Walbro FP. Through the course of the install I touched a lot of wire and connectors so I've been checking everything I can think of looking for something loose or broken. Brenspeed hasn't offered much help though I do understand that its likely not their stuff that's the problem. I spent a long while on the phone with SCT trying to verify that the stock and custom tunes didn't get get jacked up somehow. Everything supposedly checks out tune-wise. Probably a long shot but I had to check the box. So, I'm running out of ideas. Any suggestions would be greatly appreciated.