S13 KA24DE Power drops while driving, Code 55

[Oh Em Zee]

Hi,

My 93 KA24DE S13 power drops while driving. RPM reading stays functional (So, should I eliminate the distributor? or does RPM reading come from somewhere else?)
-The power drop feels like it is electrical based - 100% power loss, throttle does nearly nothing. (Might feel sliiiight change between throttle positions, but still losing speed on freeway etc)
-I just soldered in a new MAF connector from Wiring Specialties in case it was the connector, but the problem persisted. MAF has been cleaned.
-I know I have a small vacuum leak, which sometimes effects my idle slightly, but is very minimal. It shouldn't be enough to suddenly drop power, but I'll mention it anyways.

Just pulled code 55. Never get a CEL during the power drop. Frustrating..

[jumboflan]

it's probably a clogged fuel filter. Try a new fuel filter.

[Oh Em Zee]

So, I've replaced my fuel filter exactly 3,000 mi ago (S13 fuel filter, not Z32).
The power drops once every ~30mi on the freeway for about 1-3 sec at a time, and comes back after a clutch kick every time. Feels electrical, because it's a hard jolt power loss.

+ I can eliminate the distributor: RPM still shows on tach. Dist signal -> ecu -> tach = OK

- It could be fuel related still, hence the lack of CEL code. Fuel pump does not make any loud noise, but it is a coupe w/ full interior. Not sure if that makes it quieter to hear. Could have 215k+ mi on the fuel pump.

- Grounds could still be a possibility. Ordering a wiring specialties grounding kit to reinforce grounds.

[hollerjeet]

if only there was a way to log fuel pressure on the fly. sounds like fuel pump.

[1Badhatch]

Put tape over that vacuum port u left open test drive I make a killing in the 240 game fixing cars with either fucked up injectors o rings and vacuum leaks

[Hoffman5982]

Have the car idling and go into the engine bay and start tugging on the wiring harness in different places. I've had 3 s14's that had a problem similar to this but worse. I always found a break in a wire where it curves from the firewall to along the fuel rail. Just tug and see if the car shudders and start working in from there til you find the specific wire. My s13 also recently did this and it turned out to be a loose connection on the ecu plug. When my distributor died the tach would drop to zero whenever it cut power

[Oh Em Zee]

Solved! Bad MAF. Following up on this for future internet searchers.

- Problem randomly occured. Typically on freeway. In a sudden jolt, I would get zero throttle response. I could mash the throttle or dump the clutch, and typically nothing changes. Sometimes I could suddenly get 100% power back. NEVER any CEL... making it stupid hard to figure out. I replaced my MAF connector, cleaned my grounds. Still issues. Then one day, I finally saw a code appear when the engine dropped power. YAY, a clue! It pointed to the MAF. I bought a used MAF on Craigslist for $40, swapped it in, and zero problems since! ~3k mi.

(Then a fuel injector died. Yay!)

Cheers