I'm having an issue with my ITR. Not having any luck with the mechanics I see because the issue comes and goes and the car isn't throwing a CEL. When I say comes and goes, it could be months between occurences, or I could have it every day for weeks.

And, apologies for my lack of 'tech' talk.

There are two parts to this problem. Driving and idling.

When driving, any gear, any speed, the power will seem to drop out and come back in. Sometimes it's really quick, sometimes it seems to drop for seconds at a time. I especially notice this on the highway. No change on the tachometer that I can see.

So I could be cruising on the highway and all of a sudden the car will dip forward and engine sounds quieter. Tach stays steady. If I keep my foot steady, eventually it will pick back up with a bit of a shock to the drivetrain. If I jam my foot into it when it dips off, nothing will happen then BLAMO throttle comes back with a big shock to the drivetrain. If I clutch it at highway speeds often the revs will just fall to zero and the car will stall. Driving around town when this is happening causes a lot of issues when changing gears because you start to give it gas after a gear change and nothing....nothing...BLAMO!!

At idle when I'm having this problem the car idles around 200-400rpm. Much lower than normal. Often it will hunt up and down between 0-500rpm. Stalling many times. If you pop the hood when this is happening and look at the engine, it's shaking violently. I'm pretty sure it's going to rip itself from the mounts one day.

The rear bumper of my car is covered in black specs and blobs and there is a lot of soot on the rear valence. When I say blobs, I mean like a droplet of something black hit the bumper. Fuel? oil?

I have no idea what's causing this. Mechanics look at me like I'm some delusional old woman. No CEL's with this issue. Not even when the engine is ripping itself from the mounts. I have a new IACV. They tested the distributor, but it passed. Again, the issue comes and goes, so I don't take that to mean much.

Thanks for the help.
Any advice, insight, whatever would be appreciated. This is really starting to annoy me.

UPDATE 02-03-2010 - POST #30

Thanks for all the help guys. Lots of pointing to the O2 sensor and as it turns out:

Dropped the car off at Acura. They found that some wires for the O2 were rubbing on the driveshaft, so much so that all the insulation was gone in a couple areas and it was metal on metal contact. They believes this to be the cause of the issue. Car jiggles, the metal side starts contacting the drive shaft and screwing with the wires. Made sense to me. I guess the previous owner had a wide band O2 in there, so the wires were poorly stowed.

I'll get the car back tomorrow so I can see if the problem is gone.

UPDATE 03-21-2010 - POST #33

Well car came back, problem persisted. I took it back to Acura and they diagnosed the issue to be a possible defetive igniter/coildpack. They replaced igniter, coil assy, cap assy and rotor head assy. When they test drove it, problem remained. They then diagnosed it as an alternator issue. I was skeptical as I have saw signs last summer of the alternator going bad (dim lights, slow windows) but had the engine problems long before. They were confident, so I went ahead and changed it. Problem still exists. Getting pretty close to driving heR off a cliff!!

UPDATE 03-28-2010 - POST #50

Just as a follow up, car is basically undriveable at the moment. Problem has gotten much worse. Car stalls any time I engage the clutch for any length of time. When car is started at rest idle is below the min line <500rpm and very rough. A lot of hesitation on the highways. Almost impossible to drive around town without it feeling like an engine mount is about to tear out. Very strong fuel smell in the exhaust and lots of black smoke if I rev it up.

Car goes back to the mechanics tomorrow for more trouble shooting.

UPDATE 04-16-2010 - POST #58

Just an update: The problem has stopped. No idea why. Car has run flawlessly for all of April.

For those wondering, I've taken it to that dealership because despite this problem they're fantastic to deal with and are genuinely trying to solve. We've also worked out all issues with paying for parts which didn't fix the car.

UPDATE 08-08-2010 - POST #61

Well folks, problem is back!! lucky me. I've noticed something strange, just by fluke. When I was having these issues I started checking some wires and connections under the hood. Pulled out the MAP sensor connector while the car was running and about 5 seconds after I did, the car returned to normal idle. This 'trick' has worked every time since. I have a new MAP sensor on order, but am skeptical that this is actually the problem.

What would unplugging the MAP sensor do to the system to make resolve the issue?

UPDATE 08-10-2010 - POST #70

I made some videos:

http://www.youtube.com/watch?v=9xko_gZxMtY

http://www.youtube.com/watch?v=4tP_OFq7G1s

http://www.youtube.com/watch?v=q7eQUMuZ7rs

http://www.youtube.com/watch?v=GJIB7EM8_yM

 

I would try fuel cleaner, maybe a new fuel filter? Also change your plugs.

Are there any mods to the car?

 

Good ideas, thank-you.

I've tried fuel cleaner a few times with no noticeable change and spark plugs have been swapped.

What's the theory on the fuel filter? what would a dirty fuel filter do?

I originally thought it might be a fuel supply issue, but my injectors seem fine.

Car is mostly stock. Just an AEM intake. Previous owner had it modded, I believe, as there is a bundle of wires near the O2 sensor. I'm told for wideband O2. After hearing that, I thought O2 sensor might be to blame. Is that possible?

 

I had a similar issue but my car would die.I couldnt figure it out but after I got rid of my distributor it stopped.I also have a friend having the same issues right now and he and a fwe other guys are saying its either the iacv or the inside of the dizzy.I dont know if that helps but you could check and see if they resolve the problem.

 

Your motor is shaking from an imbalance. This would mean that your troubles are likely with a single cylinder rather than a systemic problem. Check the spark plugs and see if any cylinders are running worse than others.

 

Substitute a known good MAP sensor.

 

Had a friend with a similar problem and it turned out the one of the injectors was dirty as hell.

 

Fuel injector cleaner and a fuel filter won't fix an intermittent problem. It sounds to me like you have two problem: Intermittent low idle and loss of power/signal to the injectors (since the tach stays steady). This will be a difficult problem to troubleshoot unless the problem is happening while the mechanic is checking it.

 

i had the same exact problem and it turned out being the fuel filter....

 

Was it intermittent?

 

well fuel filter should be repalced every 15k miles for starters, could be a faulty injector, do all of your grounds have a good solid connection? tranny vc and termostat? make sure the vc one is on the actual grommet not on the space vc hole. could be an internal inssue with your dizzy as well, when was the last time you replaced cap and rotor? last time you changed plug wires? could be getting a poor intermitent connection

 

I couldn't have explained it any better, experience the same exact thing. It's been since the summer though that the idle and throttle bullshit will occur, but I still have a huge dusting of black **** on my rear bumper and hatch, and it builds up real quick.

It does feel like the gas just cuts out, then after a second or so, you'll feel a boost...and this will come and go while driving city/highway.

Advice from a lot of people with mechanic experience said to change the fuel filter when I explained the problem to them. Never did because it stopped at the end of the summer and I really don't feel like replacing it anyway.

 

i have had bad o2 seneors do this to me.

 

That's odd. I could maybe seeing it be the upstream sensor, the downstream sensor is kind of bullshit, it just makes sure the primary one is working correctly.

 

agree

 

just a stab in the dark, as i know little about knock sensors, but would the ecu throw a cel if it detected a sever knock or missfire?

reading this article helped me a little bit: (found here http://www.freeengineinfo.com/knock-sensor.htm)

just a shot in the dark, but what if your sensor was messed up, and thought it detected a severe knock which in turn retarded the ignition timing severly which gives you the lack of power then boom feeling.

i bring this up, only because while i don't own an ITR, when i mpfi'd my civic i had two wires that effect ignition timing switched, giving me the result of super retarded timing till about 3500rpms, which made it difficult to take off from a red light. it would act gutless and boggy untill i hit about 3500rpms, then would just take off

again, just a thought

 

Really sounds like a fuel issue...if it was a sensor it would happen all the time.
For the $30 it costs, get your injectors cleaned and another $20 for a fuel filter. They are maintenance things anyway so you're not loosing anything by replacing them, just ruling them out.

If it isn't them at least you've isolated it further, and came move on with your diagnostics...

 

I had a similar problem with my 94 ls integra. It would drive normally then random just cut power but the tach and speedo wouldn't budge. Then it would come back on after a second or so. No cel came on or nothing. It ended up being the o2 sensor. Now since your car us obd2 I wouldn't know what o2 it would be for you, but I assume it would be your primary o2. Goodluck!

 

Thanks for all the advice guys. I'm going to start with a fuel filter and cleaning my injectors. We'll see what happens after that. I'll report back.

 

turn your key on and wiggle the key in the ignition. see if the ignition lights go on and off. you could have an ignition switch thats cutting out intermittently, i've see this happen quite a few times, a seriously clogged fuel filter will more likely cause total loss of power or starting issues

 

If this problem was the result of a bad O2, it would deffinitly be the primary for us OBDII drivers. I had similiar problems with my OBDII Integra, replaced it, and those problems went away. It wasn't until later I started experiencing the OP's issue, and I am positive my primary O2 is functioning correctly, so I know that can't be the problem, it's probably something else thats as simple as an O2...

 

A good way to rule out bad O2 sensor is to run a chipped computer and turn them off. I would also buy a wideband and see what is going on with the A/F when it tries to stall.

 

+2 on the wideband.

agree with most, that it sounds like a fuel problem. getting a loss of fuel. or not getting a good enough spark in a cylinder. make sure all your wires are going to the right plugs.

get a new fuel filter. like someone said, its general maintenance anyways.

 

most of the stuff in this thread would not cause intermittent problems

if i was you id just do a quick tune up of the ignition system, most likly it wont fix anyhting

run it in open loop and see if the problem arises again or, when the idle goes down or when the problem happens then remove a main sensor(map,tps,o2)
if the problem goes away at that time
then that means its a sensor.

if not then its somenthign mechanical like the injectors clogged or feul filter,feul pump, wiring, or whatever

 

+3 on the wide band O2 sensor. Most likely the signal range on the wide band is out of range for the stock ecu and making it go berserk.