Green_EJ8

I've searched and can't seem to find much info about this that is relevant to what is happening.
I have a 1998 EX d16y8 w/ automatic trans.
When driving it'll get real jerky around 1500-2000 and the RPMs bounce between the two and the car violently jerks back and forth. I replaced the IACV and it did nothing. TPS seems to be fine when hook up to multimeter. Recently had TB cleaned, but i took it off and had a larger TB put on today with a IACV blockoff plate. so now the iacv isn't hooked up. car idles decent now just still jerks in low rpms while driving, or if i slightly press the accelerator to 1500-2000 range.
it already has new NGK plugs and wires replaced maybe 1k miles ago, i have an upstream o2 sensor i'll be putting in tomorrow and adjusting the idle screw a little more to see if that helps. It's been doing this for quite some time and is really starting to get annoying and just wanna get it fixed.
only code it was throwing before was P0505

CaliforniaSnow

Try replacing the distributor and specifically the Ignition Control Module. My rpms were jumping erratically but with mine I couldn't pinpoint when it was happening. The mechanic I took it to couldn't ever replicate the problem so he just replaced the distributor (which he had done for me before) and things have been running smoothly since. I too have a 1998 LX.

There are plenty of videos on Youtube showing how to do it and it seems pretty simple. Good luck.

S7EVEN

Agreed my civic did the same thing and then finally died leaving me stranded .. replaced the dizzy and all is well now..

CaliforniaSnow

Since I couldn't ever get the problem to be consistent I couldn't ever figure out what the heck was going on and I found myself stranded MANY times and it was seriously frustrating. Stranded on the side of the freeway, stranded in the middle of the intersection, on the side of the road. Thankfully, some very helpful people pushed me off to the side of the road each time. It was pretty embarrassing.

Green_EJ8

it's never killed the car or anything. it just is jerky/surging at lower rpms

CaliforniaSnow

It might be worth testing out. I believe AutoZone will do that for free (at least some AutoZones). The AutoZone close to me said they did not have the capability but they did say others did. And ICM will run somewhere around $80-$90 I think. Good luck and I'd love to hear when you solve the problem.

Green_EJ8

yeah i'll have to try it. worse case scenario i'll just take it back if it doesn't fix the problem. thanks!

Civic--mini me

Did you check your FITV yet? Try cleaning it out. As for the iacv delete when i used to have that my car started jerking and jerking so i put it back and everything is good now. The IACV lets air bypass the throttle plates to increase engine RPM and smooth engine operation. Since your iacv is not present anymore this is the reason why it is jerking and it feels like its lacking some air when you press the gas for a second and let it go.

If you want try putting back your tb and iacv and drive it with the iacv and again with out it and youll see what im talking about.

Try cleaning out your fitv and look for some leaks too.

tony_2018

98 civics don't have an FITV, why do people keep sayin to check that?

Green_EJ8

Ran exactly the same before TB switch/iacv switch. Its actually a edelbrock 65mm for a b18. Was going to replace the ICM today when I went to do cap/rotor replacement but the screws on the heatshrink were already stripped. So now I may be replacing the dizzy. How do I know which to get? I was told it was stamped on the metal but I see nothing. All I know is i have a 'TEC'. thats whats on the dust cover inside the cap. its a 98 ex coupe automatic. Also, if I order a new distributor will it come with a new ICM? I know that seems like a dumb question. All the autopart stores around here are asking over 200 but its on rockauto for like 120.

tony_2018

If you have some vice grips you might have a chance at changing it out but replace those screws asap. I had a similar issue and vice grips or pliers and a strong arm got those screw off. If you want to get all red neck on it you can probably take a dremmel to it and make a slash across the head of the screw to make it a flat head and go from there.

danbboy

Maybe a dirty throttole body or IACV?