So im gonna start from the beginning and tell you everything i know about this car so far so maybe you can help me out. WHENEVER I SAY I "replaced" something, usually its with a used part. I'll try to specify otherwise..

This is a 1990 civic lx sedan with a replaced b15b2 engine DPFI 80k
I bought this car a couple weeks ago, when I purchased it, it was almost out of gas. So I put 20 bucks in. I drove it 30 miles home and noticed on the freeway a lag/sputter when trying to accelerate. but above 4500rpm it seems to boogy with a constant powerband and no sputter.
When I got it home, I put a couple different distributors (yes, the one actually meant for the setup) on, brandnew NGK sparkplugs (previous owner had autolites...smh), replaced sparkplug wires. still sputtering.
Next, I changed the car to multipoint. as far as i know, Its a ZC intake.
I dont know much about cars, my boyfriend does all the work, but we tried a couple different ECU's to see if it would change anything... NOPE!
Might i mention the entire time this sputtering is happening, no CEL.
The car kind of idled low so we replaced the throttle body gasket and seemed to stop my car from seeming like it was going to fall on its face when idling. next, we tried checking the fuel pressure, when bleeding the filter we noticed rust particles, so we changed the fuel filter. Still sputs, so we replaced the entire fuel tank.
same day we did that, it seemed to not sputter, but still lags and gutless. I ran out of gas on my way to work, but strangely as i was waiting for someone to bring me gas.. the needle on ,y gas guage slowly rose to half a tank, but wouldnt start. kind of wierd and after filling my tank up my guage works fine.. but it started to sputter again.
so NOW I bought my car a obd0-obd1 jumper harness, got it a chipped po5 ecu hoping an upgraded obd would be finicky enough to thhrow a CEL...
STILL NO DICE!!! We bought a new thermostat, replaced it. and now the car surges at an idle. its always missed when idling, but now from time to time when cruising instead of it being more of a sputter, its a misfire. mostly noticeable when you first try to take off and accelerate. Kind of sounds like im running on 3 cylinders from 2000-3000rpms but sounds fine the rest of the time. I still have that powerband above 4500rpms tho.

OKAY PHWEW.
Now id like to hear your opinions on the problem... what is causing this mysterious sputter/misfire?

 

Tough one.

Check this for your surging at idle
https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/how-fix-your-idleing-woes-fitv-iacv-2153910/


For the missing maybe look into these suggestions;
Sounds like your mechanical timing might not be correct.
Inspect the timing belt,crank, and cam pulley alignment.
Also check ignition timing with a timing gun while disabling the electronic ignition advance (paperclip in service connector).

Are you sure all spark plugs are firing?
Disconnect and reconnect each plug wire with the engine running.
When you disconnect a plug, the RPM should dip.
If you disconnect one and there isn't a dip, then your plug isn't firing.

One last thing to check is your catalytic converter.
If it starts going bad, it blacks up the exhaust and the engine runs horrible.

 

timing is right on.... the car is fully obd1 converted .... would a alternator cause this??? charging voltage is good tho

 

no, it wouldn't.

What about the other things to check?
Timing is just one of the more obvious ones.

 

^Mechanical or ignition or both?

Adding to 4drEF's suggestions:

Do all 4 injectors spray fuel?

Have you compression tested the cylinders?

 

Tried a compression test and hose wouldn't thread all the way into spark plug holes. But spark plugs thread in fine

 

Buy, rent, or borrow the proper adapter.

Also answer these:

 

Every thing Ron & 4drEF is spot on. If you suspect a clogged cat a no cost test is just to disconnect the cat to see if the problem clears up. Your car will be loud as heck so I don't recommend a test drive late at night. hahahha.

Make sure to use HEI tester when testing for spark. The old screw driver method is for older cars like a 1970 240z.

 

I love all the suggestions I really do! Currently in the middle of moving so all of these tests will be done once I have the time.
I drove my car for the first time today since creating this thread and seems like after messing with the spark plug wires and removing the spark plugs and such that she no longer misfires and sputters. But still gutless a'f ! Seems more like a lag/hesitate you know? The cat is on my list most definitely. I'm planning on just straight piping my car. I have the pieces to do it in my trunk.

Keep the ideas coming! I will do those tests and let you know how it goes.

 

Have you checked/adjusted the ignition timing?

 

I'm working on getting a timing light. With all the moving and car troubles its been tough.
Newest update:
I drove 180 miles round trip to see my brother. On the way back my tach would drop to zero, lights would dim, and my seatbelt would come forward. Sometimes ill go to try and start my car and it'll turn over and start but as soon as I release the key to go back to on it stalwart and dies. If I try a few times it will start and run and I can drive away until the next time I have to start it. Could this be ignition? A lot of people are saying a leaky head gasket? I still need to do all these tests but I thought I would update you for the time being. Once I do a compression test I will update again. I have an exaust in my trunk (straight pipe w/ fartcan) just needs to be welded up! So if a plugged cat is the problem, ill let you know. Thank you!