Stock fuel pump w/ upgraded FIC injectors. Been running this setup for 6 months.

Extremely rich tune. Plugs are black and might even have traces of liquid gas on them (could be fouling new plugs extremely quickly). Smells like 1970 (no cats/cutout/cam/etc), and struggles to run on initial cold start. Without feathering the throttle, there's no way it would keep idle after starting (starts right up on first crank, but won't stay running). I lightly throttle the rpms up a bit (1100ish) for the first minute to keep it running. Often stumbles/hesitates off idle/stop (warm or cold), and rpms surge at <5mph.

The car starts just fine once @ operating temps

Fuel pressure gauge @ the rail shows 58psi and holds when key is "on", and engine is off. Once started, the car spikes to 68psi (which is 10psi higher than normal), and holds steadily.

Injectors aren't leaking and pressure doesn't seem to taper down.

Does this pretty much indicate a bad fuel pressure regulator? If this were the case, I'd need to remove the entire tank/pump assembly correct?

Ideas for a replacement? I guess it wouldn't be the worse thing to upgrade to a Racetronics unit (do they sell a regulator in addition to their pumps/hotwire kit?).

Thanks for the input.

 

Something is definitely wrong.....

First 10# fuel pressure is not so extreme that the car will not idle. The car will be rich, but the o2 should be able to correct for this amount (about 8%).

Did you retune for the different injectors?

Also did you verify your gauge with another? Some of these gauges are not that accurate.

I have new regulators in stock if you determine this is your problem, but I suggest you look for a pinched return line or bad gauge first. Typically a bad regulator results in low pressure.

 

Larger injectors have been accounted for with hp tuners. I'll grab another gauge to verify the pressure spike is indeed accurate. I'll update with any new findings.