I'm at a loss...

S5, NA, MT. Stock w/ SAFCII

I just replaced the fuel filter, set the TPS according to Karack, and had everything fixed, or so I thought. Having said that, the issue is as follows:

Day 1
After the car would heat up to normal operating temp, I noticed a bit of power loss in random spots across the RPM range. Random in that it wasn't in the exact same places from occurance to occurance. sometimes up top, sometimes around 3k, sometimes around 5k. Mind you, this would not happen immediately upon reaching operating temps. The engine didnt really sputter, just didnt have that smooth push. A few minutes later, I lost enough power that I could not accelerate on the freeway. I was sputtering badly and decided I wouldn't be able to make it to work.

Day 2
Replaced fuel filter, set TPS, set the little screw under the black cap on top of the TB. car definitely had more pickup and go right off the bat, apparently the old fuel filter was in need of replacing. HOWEVER... I lost power again. Same sputtering refusal to rev all the way and produce full power. It seemed that when testing it (free revving on the side of the road) if i very slowly pushed the throttle, the engine would spin a couple grand faster than if i just tried to stab the throttle. To me it seems like there is a fuel restriction, although I have no idea why this would happen.


Also, this started occuring a day or so after I replaced my alternator with a turbo alternator hopped up to 140 amps. would the alternator being a turbo alt be an issue? it fits and creates good power.

Any help would be appreciated.

 

Oh and I plan on flushing the fuel tank and lines between the tank and filter this evening after work. Will report the outcome. In the mean time, if you have any knowledge to share please do!

 

Checking for codes would be a start. There's a single wire Green check connector near the battery/leading coil. Ground this check connector and w/key to on it will spit out any codes.

 

17- feedback system for O2 sensor. completely nfamiliar with this system
18- Throttle sensor- narrow range. which is the half of the TPS that only does the very low end of the throttle... But that doesnt make much sense. I just adjusted it to 1V per Karack's method. backprobed the green wire. At this point I think I may need a TPS... Any way around buying a new one for like $400??? I've found that buying used electrical parts for FCs is all too often a waste of money.

 

Rock Auto - ULTRAPOWER Part # TH226 - $183.79 ('91 RX-7, N/A)

 

oh man... I forgot about Rock Auto. I bought a TON of parts for my old S13 from them... Thanks!!!

Also, Anyone have any info on this O2 feedback system? Maybe my search wording is ineffective...

Just found this... http://www.banzai-racing.com/FD&S5_error_codes.htm
Which indicates that I should check:
Fuel Pressure
Ignition Fuel Leakage
Ignition System
Air Leakage
ECU

Makes sense, my fuel filter was *****. Time to pull the plugs and diagnose, I think. Maybe replace if he car was running that lean.

 

fuel filter sock.

 

that too! I think I'm gonna make some kind of oversized pre filter, maybe...

 

did you try disconnecting the SAFC and trying the setup that way?

 

New TPS installed... but now my instrument cluster is being retarded. As if I have a messed up ground... I removed the upper intake to remove the TPS (bottom bolt had been previously replaced with a screw.... wtf??) and now my volts, oil pressure, and water temp gauges are off whack unless im just idling in place... FML.

Any thoughts, people? I dont even want to drive my baby long enough to see if the TPS helped.

 

Ok found a grounding issue in my dash. Electrical problem fixed, but now I still have the power loss issue. I was able to drive on the freeway very briefly, but when I got off the freeway and went to get back on the other way, the engine would barely idle all of a sudden.
I turned it off for about 5 minutes and was able to take streets home without any problems. I'm guessing there is some major crap in my tank, or injectors are going bad

 

This sounds a lot like my situation, minus the being shocked part.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/engine-boggs-down-any-given-rpm-930696/