hesitation while cruising around 4000 rpm
 

im having some hesitation while cruising on the highway around 4000 rpm... its patterned, not random... the car will cruise then just slightly hesitate, then go back to normal then hesitate in a uniformed pattern 2secs normal .5sec hesitation... any ideas? its a b16a with cold air intake...

hmmmm shouldnt be like that

no ones got an idea? im going to clean my air filter and check my spark plugs. what else could it be?

what car?

b16a in a 90 integra

which pcm are you running? check codes

im guessing its stock, im getting 7 long then 4 short then 3 short... i tried looking it up but there is no code for 743 or any variation on those numbers

someones gotta have an idea...

7 long and 4 short is 74. which is cylinder misfire.

The last 3 could be MAP sensor.

hmm....

clear the codes (take out the ecu fuse or disconnect the battery for 30 seconds)

take the car for a drive, if the code turns on at the point of hesitation (and it turns out to be 74) then it would be the misfire causing the hesitation.

easy enough to do... i wonder why it would be misfiring though?

depends on a lot of things. 74 the 4 being cylinder 4 is misfiring so mechanically, look at spark plug condition. wire condition as well as rotor and cap assembly (carbon tracking, corrosion on electrodes) would cause mechanical misfires.

or possibly a lazy injector. lots of reasons. all relatively easy to check out. but one step at a time.

I had the exact same problem a long time ago when I first put in my AEM CAI. I changed the plugs but the same problem was still there. I changed the plugs and cap and the problem was solved.

yeah i inspected the cap and rotor, plugs and wires before but ill check again and more closely. i went for a drive and listened closely and i am getting a little bit of a backfire as well

i bet it has to do with the dual 02 sensor's if its a jdm motor.

you think? does anyone else think this?

try switching the connectors on the 2 o2 sensors, or replace them both with a generic heated 02 sensor and wire in the heaters for both

i think it's just replacing the plugs and wires.. inspection can only go so far.

Plugs, cap, rotor, ignitor, plug wires..

now that im done mid terms ill start with that list... but its all fairly new i think but you never know

sure the car will run better, but im almost positive none of that will fix the hesitation, which is caused by the 2 o2 sensors.

igniter fixes the no start / jumping tach
plugs wires cap n rotor is just basic maintenance

the 2 02 sensor's is a serious headache in pr3 ecu's

hmm... where is the second one located? i found one just below my oil filter... the one i spilled friggin oil all over...

needs new plugs, every else seems alright. both the 02 sensors seem fine...

and from what method did you deduce that the 02 sensor's are good.. hey they look ok they're plugged in?

its your choice, im done making suggestions

the dual 02 sensors on the early pr3 b16a1's is a known problem, google it,