hi Guys, I'm new here, obviously. my car is an automatic, with roughly 160k Km's on it. I know nothing about cav's let alone cars.

ok I'll do my best to explain the touble:

first this is an intermittant problem, I have yet to figure out how to replicate it. I've also had a tune up that includes plugs, wires, fuel/air filter, and oil change.

Sometimes when sitting at a light the engine will idle really rough, like almost to the point of stall. Other times the idle will bounce between 500 RPM and 1500 rpm. I'll have to put it in neutral and feed it some gas, just so that it will settle down. Soemtiems when I do that, it'll actuall cause the car to rev up to 4000 rpm and just stay there for a few seconds (thats when it scares me the engine might blow).

When driving, I notice that the car hesitates a lot. I will accelerate from a stop and the car will lurch. meaning, start moving, then bog down completely to almost a stall, until I jam the gas, and It moves again. Needless to say, in stop/go traffic, its scary!

I've been dealing with this for about a month now, and I've had the check engine light come on twice, but go away as well. I thought check engine lights were to stay on if there is a problem?

ANY help would be greatly appreciated, I need to figure this problem out soon

TIA!!

anyone, please?

I had the same issue on my 2000 Z at around 160, 000 kms. I had a rough idle when stopped at lights. Almost sounded like it was ready to stall. CEL codes come up as 0300's (cylinder misfire). At the time I was using Bosch plugs for the last 30,000kms. Changed back to AC Delco and all is fine.

Are you running AC Delco plugs? If not, that is where I would start.


tygriff

Has youre throttle body been cleaned out?. I am thinking youre IAC unit is carboned up or on its way burnt out. I would recommend getting those things done, Then see if the problem continues, You could also so have a vaccum leak hose, Or gasket.

Good Luck.

thank you for the posts. Where is the IAC located in this engine?

Sounds like the problem i'm getting, I switched my spark plugs and had the same issue. My check engine does the same but the code says something about Evaporation. I still have no clue what's causing this

Tekne3k,

I had this issue as well but did not think it was related to the rough idle. I was pulling a code P0440 which is a evap system fault. I fixed it myself using a $36 part from the dealer. Do a search under P0440 and you should be able to find out how to solve this issue.


tygriff

check your map sensor and the hose from the map sensor make sure its not cracked

MAP sensor? I'm aware of the MAF sensor, but what is the MAP sensor, and where is it located

MAP sensor, please.. anyone know where this is?

ok, I bought a code reader, and found that the code is DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage.

so I would guess that the map sensor needs replacing, or can it be cleaned? Does anyone know?

I feel like I'm carrying a convo on with my self.

SOMEONE has to know where the MAP sensor is on a 98 z24. please ????

MAP sensor on a 98 z24 is located on the right hand side of the throttle body.
it has a rubber hose coming out of it and then going into the middle of the intake manifold (its about 3-4 inches long)


i kinda have the same issue...just not as bad as you.
my car is also a 98 z24 auto and sometimes at a stop light the idle will bounce around and dip down somewhat.

heard of a lot of ppl with 2.4's having this problem-so it IS very common.
next year im going to replace my intake manifold, TB and gaskets, map sensor, IAC, and a bunch of other sensors to try and fix it.



Black 97' Z24
Blacked Out and Lovin' It...
"Z Yaaaa"

thanks, but where is the TB and do you have a picture of the TB and the sensor? sorry, I'm not exactly car savvy

I also had a similar problem of hesitation and idle dropping off randomly when sitting still. Mine was tied to a cam position sensor that was malfunctioning and putting the timing all out of whack. This also caused the engine to run rich, so if you smell raw gas at times, it could be this. I never got an engine code becasue of it...

Anyway, If you open the hood on a Z24 and stand in front of the car, the airbox will be a big plastic box near the battery to your right. There will be a large black hose connected to this box. This is the intake plumbing. Follow that back to where it meets the engine, which should be in the front of the engine bay, underneath a heat shield. This first part of the engine that the hose connects to is the throttle body. The throttle body is attached to the intake manifold, but you will have to remove the heat shield to access it. You will want to check all the sensors attached to this manifold or the related intake plaumbing, as a malfunction of a sensor anywhere in this area can cause the engine to see an unexpected reading from the MAP sensor and throw that code.


-----------------------------------------------------------------------------------------------
When American astronauts first went into space, they discovered their pens wouldn't write. So the government spent $30 million to develop a pen they could use in space........ The Russians used a pencil.

TB- throttle body

ok, the TB, like ironhunt explained is underneath the airbox setup. the TB is a piece of a aluminum about id say 5 inches in a squared diameter and has a 2.5" round hole in the center of it (where the air flows through to the engine)... it has a birage of hoses and sensors hooked up to it, as well as the throttle cables.

hey not a prob man, we all gotta learn sometime.



Black 97' Z24
Blacked Out and Lovin' It...
"Z Yaaaa"

AWESOME!

I found it all, I see the sensor, and its easy to take out . I've also found a hose that runs from the MAP sensor to the Manifold. That hose is broken in half. I'm willing to bet that this hose being broken is 100% my problem. Does anyone know the gauge of the this hose, so I can go to Canadian tire to find a replacement

Thanks for everyones help. I'll let you know when I know more.

well...just bring the hose down to them and if they are a decent parts store/location they'll just get the right size for you.

good luck man, let us know how it turns out.



Black 97' Z24
Blacked Out and Lovin' It...
"Z Yaaaa"

sorry, I forgot to post last night. I was able to get a replacement hose, and it was a simple fix. I cleared the codes, and the car is now powerful again. its nice to sit in an intersection and not worry about the car stalling

thanks for all the help!!!!

hey guys, i had this problem and i spent way more money then i should have trying to solve it (including the 140$ ignition module) and just b4, trying the solutions here i tried some others. on my 96 z24 2.4L auto, there isnt any spark plug wires, it has a white plastic housing that lowers on top of all 4 spark plugs. First time it had a crack from age in the plastic piece and the spark was arcing and causing a random misfire and rough idle. i replaced it (about 80$), and the spark plugs(bosch)..it was fixed for about 2 months then when spring came up, it started back, and got horrible, it would bump and stall at almost every stoplight. i was about to swtich out my MAP sensor or hte Cam position sensor, when i thought what the hell, ill switch back to AC Delco plugs...presto...they must be designed different make better insulation.

im sure the MAP sensor was the solution to some of these problems on other cars, but if your having these problems, then inspect that housing for blackened cracks(if you suspect any areas on it, then at least smear some silicon caulk on them), then replace the plugs with AC Delco, NOTHING ELSE....i know everyone says it on these forums and sometimes it doesnt help but i now believe it is vital for this type of spark plug connections of the 95-99 Z24's. If that doesnt help, maybe inspect that housing once more, then move on to the other sensors. PLEASE TRY THIS INEXPENSIVE TEST FIRST...SAVE SOME MONEY...


<img src="http://registry.gmenthusiast.com/images/nvmystyle/JBO%20background.jpg"> Race your civic?!?!..I'd feel guilty