I've got a 90 si crx w/ stage 3 clutch, lightweight flywheel, header, hi flow cat, exhaust, CAI, yet it still doesn't feel as strong as some stock sohc zc's my friends have. The motor has 230k on it, but was supposed to be rebuilt before i got it(which i believe it was at least re-ringed cause it didn't start smokin til just recently) and has about 70k on the rebuild. It just started smokin, but i'm thinkin its the valve stem seals. Checked my compression and its kinda high, 186 psi, 186, 172, & 195 psi on each cyl. It idles a lil rough and just doesn't feel as smooth as my other friends with zc and a6 stock crx's(or mildly modded like mine). Any idea? I got correct timing, good plugs, wires. Also sometimes just once bad. Haven't checked fuel pump or injectors yet.

 

Even thought they might be fairly new, be sure to take a ohm meter to the plug wires and check them. They should be even in resistance. Its free to check.

What color is the smoke? Does it puff out when you lift the throttle?

Keep us posted on this. It could help someone out in the future.

 

Explain your rough idle more. I feel that my A6 is a little more sluggish than it should be and I have a bad idle some times.

 

Well, the smoke is gray, i believe its burning oil because i'm using more than i used to(from a oil pan gasket leak), and one thing on the idle, when it idles at the rpm it should, its just a a faint roughness, like a faint low idle miss, just a slight miss, and, its hard to explain but its just slightly rough, and it ticks a little when i'm on it until about 3k rpm. Valves prolly need adjusting. The other idle problem is sometimes, especially in the cold, it'll idle at around 1500 and drop to about 650 and jump back up, over and over again. Sometimes its faster, sometimes its slower. Crazy stuff. Any help would be appreciated, i'm sick of spending so much money and being slower than stock si's.(Although i beat one of the "stout' ones around town last night ). Also, it will sometimes from a stop it will just have hardly any power and then it'll kick in.

 

looks like its time to rebuild the engine, get an engine kit and take the head and engine block to a machineshop if you wanna spend get performance parts like performance sleeves pistons valves etc its worth it if you hanna RPM high without messin up the engine fast, good luck

 

Id still say check over all the wires plugs and maybe the distributor if you have the feeling that its missing... those are all cheaper and more commonly the problem.

 

I have the exact same problem with my ZC, right down to the same low idle miss. It does it sometimes. Like when i`m at a stop light and have my foot on the brake pedal the rpm will go down like a 100 and then go back to normal. It`s like a steady low miss. Even when i`m standing outside my car and it`s running i can hear it fluxuate in idle. I figured I had a vaccumm leak so I sprayed eveything with carb cleaner and nothing changed in idle.

Do you notice anything when your driving around town and you come to good steap hill and it`s almost like your car looses all power and wants to go backwards.
Mine does anyway, i have to drop it into first gear and finish the rest of the hill. Never used to before.

I can`t figure it out. I`ve pretty much replace everything and checked everything that the factory honda manual said had to do with this loss of power and roughness in idle. Maybe i`ve missed something. I know there`s alot of people out there with the same weird problems. So if anyone had this same kind of problem and fixed it, what the hell did you do or replace.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90_civic_Si &raquo;</TD></TR><TR><TD CLASS="quote">I have the exact same problem with my ZC, right down to the same low idle miss. It does it sometimes. Like when i`m at a stop light and have my foot on the brake pedal the rpm will go down like a 100 and then go back to normal. It`s like a steady low miss. Even when i`m standing outside my car and it`s running i can hear it fluxuate in idle. I figured I had a vaccumm leak so I sprayed eveything with carb cleaner and nothing changed in idle. </TD></TR></TABLE>

I have this same low idle problem. I also think that my car misses at idle. My car vibrates a ton(window weld in motor mounts) so there are 3 rattles. I don't know if it is my car missing or for some reason the pieces spot rattleing. When I stop the 3 rattles the idle sounds ok then.
I think it helped when I retorqued my head. Maybe it is just me thinking so but I THINK that it did help some.

 

I tired to retorque my head but i have to remove the cams to get at all the head bolts. The ones i could get at i tried just to see and i put my stick on 22 and then 49 foot pounds and click. Right on with no movement. So i assume there tight. At least the ones i could get at I also did a compression check and all four were 178 psi.

I was gonna try the window sealant in my motor mounts, maybe i won`t now. Thanks for the reply, some else out there thats reading can try to retorque the head cause that will definately cause idle problems.

 

I was poking around the engine today and saw oil around the edge of the head gasket. It`s just under the cam sensor(DOHC ZC)that corner of the head. I cleaned it off and let it run for a good half hour and it was wet again. It`s not coming from the cam o-ring or the dizzy one either. It`s just that corner of the gasket, from the last bolt on the left of the exhaust mani all the way to just under the dizzy.

While it was running i sprayed carb cleaner in that spot for a couple of seconds and it started bogging down and almost died. Carb cleaner sould make it rev up not bog down, what`s up with that. Could this be my rough idle and bogging issue. I already checked the torque on the head and it was tight. I`ve had head gaskets go before and the temp guage would rise and i`d loose coolant. I don`t have any of those problems. What could it be.

 

Mine doesn't miss bad at idle, just very faintly, enough to make the motor not run as smooth as it should. As far as the weird idle, it idles high then will drop, but it only does it after its been running for a while when its colder. The smoke isn't oil btw, noticed last night its running rich and its unburned gas(smokes lightly at idle, darker with more rpm).

Last night we saw the fast idle (dashpot is what its called in my manual) was disconnected, connected it & didn't make much difference at all. We also unplugged the vacuum hose from the intake to the fuel pressure reg. and it started idling like that high low thing. My friends si just leaned out and it idled higher. It went back to normal when we connected it. We also played with adjusting the screw that effects how much air is let in when no throttle is applied, on his anyway. Mine is backed out flush with the TB and we didn't adjust it, and we adjusted his until it stopped hissing.

 

It didn't start smokin at idle until my MAP sensor went out, and i got one from a friend, but it was from some other d series, not the si of my era.

 

Can you be driving down the road and your car feels like there is a huge wind gust that just hit it(sputter)? My car does this every once in a while. The hard thing is that it doesn't throw any cells and it only happens like once a month. So it's not not like I can have anyone jump in my car to show them the problem because most of the time it won't do it.

 

Not really like that but somewhat. If i`m under load like going up a steady incline it feels like it chugging.

 

Yours sounds like it might be a fuel pump problem. It might be either a bad pump or clogged one

 

Still looking for whats wrong with mine, I plan to replace my o-ring on my distributor(i know its bad, slinging oil) and possibly the one on my fuel pressure regulator. I believe its a vacuum leak b/c of how it acts when i undo the vacuum hose from the FPR. Has anyone else had this problem? BTW, i believe part of the rough idle might be my head/valves worn out or needing adjusting, i can hear the valves up until about 3000 tickin a bit.