Bleakened

Hello, Honda-Tech peeps. This is my first post here and before I ask my question, I'll let you know my civic I have is my first car and I don't really know too much at all about anything under the hood of a civic.

I have an automatic 98 Civic DX hatch, stock D16y7 I bought from someone on Craigslist and it had a ton of small issues that I have already fixed but one large issue that didn't show up when I looked into it before I bought. (I got burned, I know.)

So when I'm idling in any gear at all, hot or cold engine, I feel "hiccups" come from the engine and it vibrates the car just once. Like a jolt. When it does, it drops about 50-100 RPM (tested with a scanner from a friend) and you can actually see the engine jump a wee bit when it does it in park/drive with e-brake on.

Me and a mechanic friend of mine who has an ASE cert. can't figure out what the hell is causing these hiccups. It's not a huge issue as it doesn't do it when driving but it still shouldn't be doing that.

Not sure if it will help but a friend told me my valves or something is "chattering" inside the engine and I need a new crankshaft pulley. It is definitely a chattering noise that you can clearly hear when accelerating but only at low to mid RPM ranges.

So is it time to do a swap or is this a cheap fix? I'm on a budget and don't plan to tune it very soon. Just my daily driver.

TL;DR, engine hiccups when idle and valve chattering under acceleration, what do?

Fliptard

can you take/post a video with audio or this issue? may help to hear it to understand a little better.

Bleakened

Aye, will post one soon.

Bleakened

So.. I tried recording what it does but I only have my phones camera. It can record in 720p but it can't catch the engine hiccups. Can't see it in the video. And the audio sucks so you really can't hear the chattering either. Anyone know what this MAYBE could be?

B_Swapped93

by hicups do you mean surging. and does it just do it once than contuniue on it's normal idle path

Bleakened

I'm not 100% sure what surging is but I youtube'd it and mine doesn't do it very drastically. It only drops like 50-100 RPM then will stabilize again. Not even enough to hear revving really. Also, I forgot to mention that it will continue to do it while idling. When I was looking at it with my mechanic, we had it running for quite a while and it never stopped. does it once every 3-5 seconds. Sometimes it'll do it a little worse and do 2-3 jolts in succession and continue on.

B_Swapped93

Most likly here's a vid (not mine) have you cleaned you'r IACV ? what does you'r idle sit at when it's not hicuping(don't know if you can put it in N while driving an auto)

Bleakened

I have never looked at/into my IACV. Mine doesn't do it anything near what it did in the video though. I idle at about 900 RPM and it drops to 800-850. I can put it into neutral while driving, yes. It does it in neutral as well.

Edit: not sure if it means anything but the jolt from the "hiccup" can be felt by anybody in any seat of the car. It feels like another car bumping you very lightly or a rough gear change.

B_Swapped93

So it drops by 50-100 from driving st stand still ? if so that's normal so is 100-200 but you mean it surges a bit when you're stationary. look into how to clean you'r IACV that could be the cause

Bleakened

It does the drop anytime im not accelerating, in any gear at all. As long as I'm stationary, it will do it.

I will look into cleaning my IACV and get back to the thread soon.

mimog3

I believe its misfiring without throwing a check engine light. I had the same issue about a month ago.

What happened with me was that the spark plug wires were acting up. I replaced them and it fixed the problem for me. so if i were you i would check the plugs and wires.

Bleakened

That's what I thought too. Had my mechanic check the plugs and they were pretty new looking, very shiny.

We both assumed the wires were good because they're just wires but ill try new ones.

Edit: remember that I don't really know crap about the engine in my car (yet) but if it were a bad spark plug wire, couldn't i start the car and then pull the wires out 1 by 1 and if one of them doesn't change the cars reaction or anything it would mean that it's bad? It makes sense to me but I don't know wtf I'm talking about. Opinions?

B_Swapped93

seriously consider the IACV as the cause have you cleaned it ?

Bleakened

No, not yet. My mechanic isn't around until Sunday. Just seein' what other people think about the issues at hand

Also, had a friend tell me it might be because of my exhaust system. It's all aftermarket except the muffler. Said something about the pressure in it and the tiny muffler screwing it all up. Sound legit? or is he talkin' out of his ***?

Fliptard

I just had my Mini-me swap give me idle issues, and driving issues, turned out the TPS was going bad, but not bad enough to throw a code.

B_Swapped93

bottle necks like that won't cause what you're describing. The iacv is extremly easy to clean,do you have a 12mm wrench and some brake parts cleaner.

Here i searched it for you:https://honda-tech.com/forums/acura-integra-6/%2A%2A%2Ahow-clean%2A%2A%2A-your-iacv-k-idle-air-control-valve-1575913/

Bleakened

Oh, I didn't know it was that easy. I'll do it tomorrow and post results.

mimog3

I'm New to this stuff myself. I had Aftermarket spark plug wires which fell apart when i had to remove them sometimes. Me being the smart-*** that i am i would try to repair the wire by re-crimping the connector so that i wouldn't have to buy a new one.

Eventually the connection became weaker between the plugs and wire which would cause a random jolt in the engine which you could feel only in park and neutral, if you revved the engine nothing would happen, only on idle, you would see the RPM Needle Jolt quickly and come back. Don't assume, the wires may look fine but you may want to replace them to see what may happen. if the car has not had a tune up this is something you may want to consider.

grdy98

^ agree check iacv. link to help you locate

http://imageshack.us/photo/my-images...43og6.jpg/sr=1

Bleakened

After the IACV, I'll check into the wires more and probably just replace them anyway.

Thanks for the insight though. You're the only one who's had the exact same problem as me. How bad were your RPM fluctuations?

mimog3

Yeah, no problem, I know everyone is saying check out your IACV which honestly I feel has nothing to do with it, but it doesn't hurt to clean it. even then I'm not a pro like these guys.

I wasn't able to check it at the time, If I'd have to guess i would say its near what you were experiencing a 50-100 RPM Difference. I had trouble trying to get it on video because you could barely see the needle move in the Video and let alone hear it. so i didnt even bother posting about it because i had no idea of how to describe it. I figured I would give it a go at trying to figure it out myself.

Because it felt like a misfire i figured that it had something to do with the either the spark plugs or wires, i replaced the plugs first, still did it, then the wires, problem went away.

Bleakened

Okay so I cleaned out the IACV even though it was clean as a whistle to begin with. Still the problem persists. I pulled the plug out of each cylinder while it was idling and I noticed it react to it on each one I pulled and put back. That should mean the wires/plugs are good and firing, right?

Bleakened

A few more notes for those reading this:

1. I found out I have no catalytic converter... lol...

2. I only have 1 o2 sensor, the pre-cat. Going to have my mechanic put in the post-cat one because whoever had my car in the past plugged up the hole for it with some kinda ****.

3. I have a 2400 watt system in my car.

4. Wtf is this thing in the tube coming from my intake that just ends..?

grdy98

yes if you pulled wire and there was a differance in motor idle then that cylinder was good , if you pulled a wire and there was no differance then thats a misfire.check to see if you have vac leak

Bleakened

I don't really know where to check for these leaks at. Remember that I'm new to this