Stumbling under load

[GTRS Fiero]

For NoMad's Fiero, the first question that came to my mind was fuel pressure.  I'm sure there are other possible causes.

I do not recall if the fuel filter was replaced or not.

[NoMad]

I had a similar thought and grabbed a fuel filter last night to drop in.

My second thought is ignition. Going to start by checking plugs and working backward from there. Coil is likely so I might resistance check it first actually.

[GTRS Fiero]

My worry is that it's ignition or timing.

[NoobKevin]

Have you checked the timing?

[Fierofool]

A MAP sensor or TPS can cause a stumble.  I believe Mike replaced the pressure regulator when he installed the new injectors. 

[GTRS Fiero]

Since the MAP sensor and FPR share a vacuum line, maybe a leak?

[MikeMac]

A MAP sensor or TPS can cause a stumble.  I believe Mike replaced the pressure regulator when he installed the new injectors.

I do remember we had to replace the fuel rail itself because it had a weird corrosion going on. We replaced the regulator diaphragm because the old one tore when we took it off to put on the other rail. Fierofool supplied the rail but it didn't have a regulator on it was the reason we took the regulator apart. Seems like that diaphragm was pretty pricey. $70 bucks or so from TFS?

[GTRS Fiero]

Better than the cost of the adjustable FPR.

[Fierofool]

Yes, Mike, the TFS regulator is pricey.  They are available from Rock Auto with prices ranging from $36 for offbrand to $55 for AC Delco.  Search for 93-95 Camaro or Firebird 3.4 Fuel Pressure Regulator.

[GTRS Fiero]

I wonder what was causing the corrosion.  Considering that the car apparently ran in that condition, it's likely that the corrosion happened on the car.