1991 honda crx si sohc zc
Hi, I recenty ran into some trouble with lightweight flywheels and thought it would be nice to warn some some of you on the pros and cons
I had just completed my engine swap from a local shop, I asked them to install an exedy 12lb
Everything worked out well except it would grind on startup
I had an appointment 16 miles away, so I asked if it was okay to drive it.
They said yes, it's only the teeth are mismtched on the flywheel/starter
so I drive the 16 miles and back (30 miles) no problem except the grind on start up.
Two days later I take it back to swap the 12 lb exedy for a 9 lb one I have.
They call me, the car is good, no more grind on start up. I actually have a follow up appointment 16 miles away same place.
Half way there the check engine light comes on

Pretty obvious the problem is the flywheel since it was the only change

I still have this same problem, tomorrow I will be going back for a stock one to be put in.
Reason for this is because the cel and when I turn my lights on, the eld kicks in and raises the rpm like normal, but when I turn them off, the eld kicks in and drops the idle like normal. But because of the reduced momentum stored in the flywheel, the car over reacts to the idle drop and almost dies
I am guessing the cel is for this problem ^ or a knock misfire of some kind
because If I retard the ignition timing the cel no longer pops up


Here are real facts from my experiance

Pros:
faster acceleration
more torque


cons:
reduced gas mileage
car probably will not pass smog


I experianced none of the drivability issues

but you do have to be smoother with the clutch and gas, I can feel it. And it might be true that you can damage your synchros prematurely


I would advise if you really must have one,, limit yourself to a 13 lb or reduced stock flywheel

I would appreciate comments feedback.
Maybe my problem is not the flywheel
Let me know because I do find it odd that the cel no longer appears after adjusting the timing

Info on what I did
Replace ELD and alternator
my tiiming is set to d16a6 specs (not sure if this is right for a sohc zc)


Sorry for bad grammar

 

I have a DOHC ZC....only "performance" mods on the motor that is in the car right now is a 7 lbs. flywheel and intake. I have no problem at all with my light weight. The only thing that I can think of that you could consider a con is that when engaging the clutch to slow down the engine will rotate real fast....maybe jumps a extra 250-400 RPMs. But it's really not a big deal. I haven't experienced any loss in MPG's, and it is alittle easier to take off from dead stop and I can feel the slight difference of the engine not having to work as hard with the stock flywheel. Yes, the 12 lbs. flywheel you had at first was miss matched with the starter. But the 9 lbs. one you put on didn't grind but "halfway there" as you say would've been 8 miles down the road and the CEL came on. Doesn't sound like to me the flywheel is your problem. Have you checked to see if you were throwing a code at the time of you're CEL?

 

A flywheel cannot set a check engine light. Check engine lights are set by emissions faults. There has to be wiring and a sensor installed for a CEL to come on.

They probably forgot to plug something in. That would be the cause of your reduced gas mileage and not passing smog. A flywheel won't cause you to not pass smog in your 91 Civic. It's just a mechanical part.

Your computer from 1991 is not smart enough to detect reduced engine inertia. Something isn't plugged in correctly.

 

The only thing I find at fault "B serious" and dont take it into offense or as I'm knockin' ya....but it didn't come on with the first 12 lbs. flywheel, he took it back and had a 9 lbs. one installed. Drove home then drove another 8 miles to wherever and then the CEL kicked on. If something had been unplugged it would've thrown it off the bat. Unless you were getting at a harness may have popped off and not been fully connected. Still doesn't explain why if he retards the ignition timing far enough that the CEL goes off.......OP, does the car drive are act funny at all besides the bogging down when turning the lights off?

 

yes, one way is 16 miles, half way there, around 7 miles the light came on when the 9 lb flywheel was put on
There is a code stored in the ecu but I don't know how to read it it just keeps blinking
my only guess is that it is a misfire code, because a friend who is a toyota dealer tech told me to change my ignition timing a bit.
Said he dealt with this same issue on many cars before

I can only assume the flywheel is the cause because it was the only change
I will find out soon though
Before I visit the shop I will adjust the cam timing and ignition timing
I have it set up like a d16a6 but maybe the sohc zc is suppose to be set the dx hf way

 

Is it v-tec or non v-tec?

 

https://honda-tech.com/forums/showth...3006701&page=2 Read this page since it sounds like you're not familiar with getting the codes off you're ECU. Another question along with your car being v-tec or non.....what OBD are you running and what computer?

 

My timing is set to the top one, maybe I need it to the lower one

To answer your questions;
I find it so odd that the 12 lb made it some 60+ miles without a cel and the 9 lb only 8 miles to throw a cel
The car runs perfectly normal
at idle, when the check engine light comes on, the light will flickr while I am signaling for a turn
also, the cel goes off when I advance the timing, move the distributor towards the firewall
Maybe I can grab a video of the light blinking and someone can decode it for me?

 

No way the flywheel is causing a CEL. You need to learn how to read the codes and track down the real problem. It doesn't matter if the flywheel is the only change, they were working under the hood and other parts can go bad at any time. It could even be a loose connection.
I'm running a 7lb fidanza on my B16 crx and it's awesome. If you know how to shift properly, there are no cons. I can only say great things about it and my mileage is the same or better.

 

I really would like to what code you're throwing OP, get back to use when you find out. Also, let us know if you're v-tec or non, what OBD and ECU.

 

I think the cel was for 20, electric load
I replaced my ELD, checked my grounds and replaced alternator. I checked all the connections, wiring to the ecu.
Unless the ecu is bad which might be the issue
I also decoded it as code 16 Which might be knock or timing problem
The engine came with a d16z6 pulley not a d16a6 pulley so maybe the timing marks are off but that points back to the flywheel swap, since those settings at the time were the same as well. and a disconnected plug would cause a cel right away I know

 

oh sorry, ecu is pm6 and car is ob0 and non vtec sohc zc
are the non vtec sohc zc blocks the same as the vtec ones?
because this one came with a three rib alternator crank pulley from a d16z6 but the head is non vtec, maybe they swapped heads on the engine

 

To my knowledge there's quite a few different SOHC ZC's....v-tec being similar to a Z6 and non v-tec being similar to A6 and different ones being OBD 0 or 1.....This is all from what I've read, I've never owned a SOHC ZC so I have no personal experience, so you can take that info with a grain of salt if you'd like. If a ECU is bad the bulb will just stay lite nonstop so it's not your computer. You say code 20 then two more lines down you say 16. I'd double check to make sure you're reading the code correctly. Because 16 is fuel injector and 20 is ELD......but as you stated you replaced that.

 

I have a link to the cel coode, I will try to read it not having to stretch my self over the seat
http://www.youtube.com/watch?v=kmFWw...ature=youtu.be

That is so confusing?
code 2

 

I'm looking at all the codes in my manual, none of them could cause this problem?
and if something was not plugged in it would be obvious right off the bat
but I checked all connections

 

That is code 1, o2 sensor. Have you tried resetting the ecu? The grinding issue was more than likely caused by only using 1 bolt in the starter. I ran an 8 lbs flywheel in my old a6 for over a year and it never grinded.

 

I wish I could see the video you posted but I cant on my phone unless I had the web page link to the youtube video itself. If it is the O2 sensor code then that would explain your poor gas mileage. Maybe try taking it out and cleaning it.....might not do anything but it could be worth a shot. I'm pretty sure in the link I gave you about the codes this guy "raene" explains about 02 sensors and how they can be bad and what happens after a few minutes driving. Because the OP in that thread was having O2 problems.

 

How did you deduce that it was code 2 when it's only blinking once?

 

thought I saw a pause

 

with OBD0 D-series ECU, code 20 would be ECU flashing 20 times - OBD0 D-series ECUs don't use long and short flashes, only short

 

o2 sensor code wont pop up untill the car gets up to temp. the o2 will also read different things based on the timing. it will also explain the poor milage.

Get the A6 crank pulley, get another o2, and set everything right.

I had a 8lb flywheel in my car and I had no CEL issues. It did grind on start up but i never worried about it.

 

I don't disagree with anything here, but it's so strange that the only cha ge was the flywheel and that's what caused it
Will try the a6 pulley and new o2 sensor

 

It's either a coincidence that a part on your car failed right after you had it worked on or the mechanics that yanked your transmission out 2 times now may have accidentally messed something up or the shop is lookin' to make an extra buck off of you by sabotaging your car. That last bit happens all the time. Bottom line, no way in Hell is the flywheel responsible for the CEL and for the love of God man, stop dickin' around with your ignition timing without a timing light lol.