S52 Swap Hard Start Issues...

[HyperMikeD]

So Ive been trying to work out the little bugs on my S52 swapped Ti and here is one I'm having a hard time figuring out. Ive read lots of posts/threads about it possibly being a ECM problem, FPR problem, a leaking injector problem, or a CPS problem. All sensors are Brand New, New CPS, New Cam Sensor, New Knocks, New O2, New 255LPH fuel pump. No check engine light and yes it works. I swapped 413 ECUs with a friends. No change. I installed a known good set of injectors with new seals. No change. I swapped the stock fuel pump back in place of the 255lph unit. No change. I installed a known good stock OBD1 fuel rail w/ FPR. No change. I installed an OBD2 fuel rail w/ aftermarket FPR set to 51psi per Bentley. I assume this deletes the anti-drain back function of the factory FPR so the internets say to wait 3 seconds for the fuel pump to prime. No change. The fuel pump doesn't initially prime but does pulse when cranking. So I wired it to a relay switched on with the ignition. Then it loads up and when it finally hits there's usually a loud bang followed by a 4 foot flame that shoots out the exhaust. So I don't think its a fuel problem ...

What are the odds that I got a bad CPS out of the box and how do you check that ??

Any suggestions ??

TIA.
MikeD.

[HyperMikeD]

Problem solved thanks for all the suggestions...