need help with my sputtering/3 cylinder (kind of) problem

[n_hall]

a couple weeks ago i repaired my afm and replaced my fuel pressure regulator, and zip tied all vacuum connections. my car ran better than it ever has in my ownership of it. before that it would sound like it's running on 3 cylinders, but noid light and spark plug light testing showed that all four were getting fuel and spark.

fast forward a couple weeks and it started to sputter anywhere between 2k and 4k. and it also switches to the 3 cylinder running normally when i try to accelerate a little faster than a soccer mom in a minivan. it will do that until i let off the gas, it will then run normally but probably sputter.

it's starting to get on my nerves every time i drive it. i was trying random things trying to fix it. today i replaced my afm with a used one on ebay, but it's running the same. i tried running it with the o2 sensor unplugged and it runs the same as with it connected. could it be the o2 sensor? anyone have any ideas?

thank you,
nick

[running_cold924]

a noid light will only show if the injector is receiving power to be turned off and on and has nothing to do with spark.

sounds to me like you are having an ignition problem.....what for plugs are you running? how old are your wires, cap, rotor? all of these will create a misfire under load

does it miss on initial start-up?

[white944cup]

This is a long shot, but you never know. My brother had one that would drop a cylinder intermittently......the problem would come and go with no apparent connecton to driving conditions, weather, etc. Compression check was good.....he replaced all the usual suspects....plugs, cap, rotor, wires, AFM, TPS, crank sensors, ECU, all to no avail. Finally pulled the head and found a broken inner valve spring.....apparently the pieces would move around and occasionally would bind up and prevent the valve from operating properly. You never know with these cars...........

[Aufgeladen944]

Mine sputters on initial startup, then drives fine. I'm not sure if it's misfiring, just idling weird and the throttle is extremely slow. If I let it sit and idle up for about a minute, the car drives fine.

I did change the spark plugs to BPR7EIX iridium NGK's, which is one step colder than stock. I can't see how that would mess things up really badly. I have also always ran rich, and I'm thinking maybe I should have kept the original temperature plugs.

Thoughts?

[running_cold924]

is this for your 951 Aufgeladen? mine runs like absolute piss until its starts to move on the temp gauge. I just let it sit and hold the idle @2K for a min or two. as for plugs, i'd still run the stock copper plugs (but i too went with ngk and did go one step colder)

have an a/f gauge? what are your mods?

very true white944cup.....its always something new with these old cars...

[running_cold924]

is this for your 951 Aufgeladen? mine runs like absolute piss until its starts to move on the temp gauge. I just let it sit and hold the idle @2K for a min or two. as for plugs, i'd still run the stock copper plugs (but i too went with ngk and did go one step colder)

have an a/f gauge? what are your mods?

very true white944cup.....its always something new with these old cars...

[Aufgeladen944]

And yes, it's my 951. The Honda, as always, runs perfectly. They always do...

I'm thinking it might just be a vacuum leak.

[flash968]

sounds to me like a plug is loose

ALWAYS torque them to spec and use anti-seize on the threads