Stutter on steady ideal on my b16a

This started happening this summer and right before I parked it for the winter it was doing it quite regularly.

At steady ideal (ie. 4000rpm) the car physicly feels like it's loosing and gaining power, you can feel it pull, lag off, pull lag off.. etc... It sort of feels like there is a pattern behind the lags, like a rotation, or a injector firering...

It shouldent be anything do do with the electrical, it's flawless. It also has new MSD plug wires, fairly new dizzy, with new cap, rotor and spark plugs. I've also replaced the main relay, and the ignition switch.

As for the condition of the motor, that's fine too. It's giving a strong compression of: 1-160 2-160 3-150 4-160

The timeing was also checked, and adjusted..

The only thing I am thinking now is it could the the Injectors, or the fuel rail ???

Has anyone else had this problem, any input ?

maybe fuel pump? did you upgrade it with the sawp?

Mine does this as well, but I am missing 3 sensors until the next couple days when I can get the tools to put em in, it loses and gains power when the throttle is steady for awhile, and also will lag on throttle response until it jumps to life and hauls ass. If it helps any, im missing the Knock sensor, and both O2 sensors, and it didnt do it before.

cel? vac leaks?

I assume you read what happened to josh's car....makes me sad :crying:

when you're ready for your mechanic's advice, you know where to call...thats right, I said it! :spit:

This started happening this summer and right before I parked it for the winter it was doing it quite regularly.

At steady ideal (ie. 4000rpm) the car physicly feels like it's loosing and gaining power, you can feel it pull, lag off, pull lag off.. etc... It sort of feels like there is a pattern behind the lags, like a rotation, or a injector firering...

It shouldent be anything do do with the electrical, it's flawless. It also has new MSD plug wires, fairly new dizzy, with new cap, rotor and spark plugs. I've also replaced the main relay, and the ignition switch.

As for the condition of the motor, that's fine too. It's giving a strong compression of: 1-160 2-160 3-150 4-160

The timeing was also checked, and adjusted..

The only thing I am thinking now is it could the the Injectors, or the fuel rail ???

Has anyone else had this problem, any input ?


Humor me, and try using a different set of plug wires. You don't even have to buy a new set, just borrow a set from any other D or B series motor. If that's not the problem, try regapping your plugs to a smaller gap...they may be gapped too large. I'd rather see you replace them though...just buy the cheapo pre gapped plugs from AZ. Please, don't tell me you're using the thin tipped denso iridium type...they're known for the problem you're describing. It sounds like it's misfiring by your description, so it's definitely ignition or fuel related. You may also have a faulty/dirty injector. I'm leaning towards the ignition though. Your best bet is to borrow parts from a friend with the same motor that you know work.

maybe fuel pump? did you upgrade it with the sawp?
No I havent upgraded that yet, it has definatly crossed my mind though. If I decide to do the injectors I might just it all, injectors, fuel rail, fuel pump.

Mine does this as well, but I am missing 3 sensors until the next couple days when I can get the tools to put em in, it loses and gains power when the throttle is steady for awhile, and also will lag on throttle response until it jumps to life and hauls ass. If it helps any, im missing the Knock sensor, and both O2 sensors, and it didnt do it before.
Do you RPM's jump, or skip around when this happens??

Mine seem to stay the same, unless it happens on acceleration then they pause, but don't really drop.

cel? vac leaks?
No CEL, and I did go over the vacume lines, their all fine.

you know where to call...thats right, I said it! :banghead: you've got mail :lol:

Humor me, and try using a different set of plug wires. You don't even have to buy a new set, just borrow a set from any other D or B series motor. If that's not the problem, try regapping your plugs to a smaller gap...they may be gapped too large. I'd rather see you replace them though...just buy the cheapo pre gapped plugs from AZ. Please, don't tell me you're using the thin tipped denso iridium type...they're known for the problem you're describing. It sounds like it's misfiring by your description, so it's definitely ignition or fuel related. You may also have a faulty/dirty injector. I'm leaning towards the ignition though. Your best bet is to borrow parts from a friend with the same motor that you know work.
I've already went through 2 sets of plugs. I can't remember the first set's brand, however the set I'm using now are NGK R gapped to spec.

Plug wires are brand new, probably less than 500 miles. They are the MSD Super Conductor 8.2mm or sumthing like that.

Your into Tuneing arnt you ??
You think by any chance it could be the tune on my ecu chip?
I burned it like 2 years ago useing the OEM EF9 basemap and bumped up vtec to engage at 5500rpm.

I kind of ruled this out since it was running fine for a little over a year on that chip. but maybe i'm wrong???

No I havent upgraded that yet, it has definatly crossed my mind though. If I decide to do the injectors I might just it all, injectors, fuel rail, fuel pump.


Do you RPM's jump, or skip around when this happens??

Mine seem to stay the same, unless it happens on acceleration then they pause, but don't really drop.


No CEL, and I did go over the vacume lines, their all fine.

:banghead: you've got mail :lol:


I've already went through 2 sets of plugs. I can't remember the first set's brand, however the set I'm using now are NGK R gapped to spec.

Plug wires are brand new, probably less than 500 miles. They are the MSD Super Conductor 8.2mm or sumthing like that.

Your into Tuneing arnt you ??
You think by any chance it could be the tune on my ecu chip?
I burned it like 2 years ago useing the OEM EF9 basemap and bumped up vtec to engage at 5500rpm.

I kind of ruled this out since it was running fine for a little over a year on that chip. but maybe i'm wrong???


Yes, i'm into tuning a bit. Maybe your rom is faulty? Can you try reburning the stock bin back on it?

Do you RPM's jump, or skip around when this happens??

Mine seem to stay the same, unless it happens on acceleration then they pause, but don't really drop.

No, they didnt drop, it just seemed like pushing the pedal down didnt do anything, like you said it "paused", and the rpms wouldnt jump, but the engine would buck a little as if I was pressing the throttle on and off every couple seconds.

I put both O2 sensors in tonight and it DEFINATELY stopped it, the knock sensor isnt in yet (its a bitch to get at from top OR bottom) so I still have a CEl but the stuttering and pausing is gone. When im riding down the road with consistent throttle, the engine is very smooth and responds to my throttle input rather than ignoring it until I really push the pedal.

I put both O2 sensors in tonight and it DEFINATELY stopped it,
Hmm, maybe I should check my O2, I only have 1 tho, right before the cat.
You have any suggested brands for a new o2 ? or will a OEM Honda 00-01 civic si sensor work?

It's hand for my to test the problem since there's a nice blanket of snow on the ground.

I also have a spair M27C256B ROM sitting here, I think i'm going to burn a new chip to throw in this upcoming summer, Ultimatly i'd like to get some dyno time with a real tuner and see what kind of numbers i can throw down. But first thing is first... get this problem diagnosed.

Hmm, maybe I should check my O2, I only have 1 tho, right before the cat.
You have any suggested brands for a new o2 ? or will a OEM Honda 00-01 civic si sensor work?

It's hand for my to test the problem since there's a nice blanket of snow on the ground.

I also have a spair M27C256B ROM sitting here, I think i'm going to burn a new chip to throw in this upcoming summer, Ultimatly i'd like to get some dyno time with a real tuner and see what kind of numbers i can throw down. But first thing is first... get this problem diagnosed.

if you're still running OBD0, then you will need a one-wire o2 sensor, not a four-wire.

most of the stuff being mentioned has been addressed.....minus the fuel filter.

i'm leaning towards the chip. somewhere the fuel is tweaked. your chipped ecu was the wild card from the start.

vt3c kickin 3800 is mad tit3 pow3r, y0! :grinno:

vt3c kickin 3800 is mad tit3 pow3r, y0! :grinno:

haha, mad tight noise tho :grinyes:

haha, mad tight noise tho :grinyes:

I'm sure in all the uber-coolness, you realize that's a sign of a power drop.

I'm sure in all the uber-coolness, you realize that's a sign of a power drop.

ohyeah, i could feel the drop right as it crossed over. what hell could someone be running to have their vtec engage at 3800rpm ????

ohyeah, i could feel the drop right as it crossed over. what hell could someone be running to have their vtec engage at 3800rpm ????

Nothing. They'd have to reduce the size of their intake and exhaust runners as well as port size on the head to need a vtec crossover that low.