I have a 90 Civic Si with a SOHC ZC engine swapped in by the previous owner. The car drives absolutely great and gets good mileage. Unfortunately I have a problem that the ignition timing is maxed out at only 15 degrees BTDC, which is outside of spec and so it will automatically fail the smog check. It should be well beyond 22 degrees at this distributer position. I jumpered the ECU connector while adjusting the timing, and I've tried the distributer in both directions. I'm not new to ignition timing. I tried a CRX Si ECU.

So then I went to verify the cam timing. I put a chopstick down the empty spark plug hole on the cylinder closest to the crank pulley. Sure enough, it hovers at it's highest point when the cam sprocket marks are lined up in the peculiar way that they have to be on the A6. I verified that I have the correct cam sprocket, timing belt, and distributer. I have two of each now. I think this rules out everything mechanical but if I'm wrong, please let me know.

My timing gun is a year old craftsman entry level timing gun. I set both my cars with this gun and I know it to be off by just under a degree. Someone please throw out some helpful suggestions. I can't get this car in my name until it's smogged, and the registration is paid but lapsed so they wont give me a sticker (and I have another car so I don't want to mess with the temporary tags). I need to have this car running for my brothers when they come to town for the holidays. Thanks in advance!!

I bought this car off this board so if the previous owner recognizes this, please chime in. No hard feelings whatsoever, it was a good deal and I'm happy with the car even with this persistant problem.

 

Are you sure that you are referring to the correct timing marks on the cam gear? If I recall the 1.5 and 1.6 engines share the same gear but have different reference marks. If it was off a tooth you would notice a poor idle, loss of power etc. hth

 

I have the same problem, my marks are right on but the distributor is all the way advanced. I have a DOHC ZC but still same thing. It runs fine but just knowing that this is off bothers me cause it`s not set right.

 

I have tried setting the cam timing according to the method for the 1.5 liters and it is one tooth off and runs horribly. It is very obviously wrong. All the documentation out there is for the 1.5 liter. That method is to have the UP mark straight up and the two other marks parallel to the head. Then I ran across some information for the 1.6 D16A6. It has another mark on the cam sprocket at the 7 o'clock position that has to be lined up to an arrow on the lower timing belt cover. This puts the timing over 1 tooth and the car runs great.

http://www.cadvision.com/blanc....html

I also found out that the 1.5s and the A6 have different timing belts. I bought a new timing belt, but the part number is the same as the one that's on there (145), and I lined them up tooth by tooth and it's exactly the same belt.

I also forgot to mention two things. The first thing is that the engine had the wrong crank pulley on there, and I couldn't get the pulley off my spare engine, so I got a DX crank pulley. According to info that I have, the timing marks are the same. And I verified the cam timing using a chop stick down the spark plug hole. The other thing I didn't mention is that the timing is fine when the engine is cold, but when it warms up, the ECU retards the timing until I am maxed out at 15 degrees.

90_Civic_Si, make sure you have the right distributer for the engine. Just because it bolts right up doesn't mean it's right. For example, I have a OBD1 SOHC VTEC ZC in my 93 Civic. It didn't come with a distributer when I did the swap, and I tried to use my DX distributer. It bolted up fine but would max out of adjustment and couldn't be timed correctly. Then I found out that the Z6/ZC uses a unique distributer to all other Honda engines.

 

My ZC is OBD1 and i converted it back to 0BD0 and i got the distributor for an 89 integra but you know i could have gotten the wrong one from honda, i`ll check part number and see what i can find out.

Mine runs awesome when cold but as soon as it warms up it seems sluggish. Thanks for the reply about the distributor, never can trust someone else saying oh yeah it`s the right one. Thanks