So I recently picked up a '90 civic Si (d16a6 of course) with 150K miles. All stock except for a header (stock cat, b-pipe and muffler) and a K&N intake elbow and filter. The previous (original) owner said he always used 93 octane...just because it made him feel good. I've been doing a lot of research on here to get up to speed on this generation. One thing I liked about the car is that almost everyone says use 87 octane or you're stupid. Well this thing pings like freaking crazy on 87. Ignition timing is set at the specified 18 degrees BTDC...procedure done correctly. If I put in 89, it still pings unless I run the timing at 12 degrees BTDC. What's the deal here...am I missing something? Would it hurt engine longevity running 12 degrees? I drive a lot of miles per year and want to avoid premium fuel if possible. I can't believe it would have that much carbon build-up to necessitate premium fuel.

Nate


Modified by dstar26t at 1:04 PM 8/29/2007

 

Adjust the valves and also check the cam timing. Set the timing by using the service jumper. Also wouldn’t hurt to run a bottle of fuel injector cleaner through it to clean off any deposits.

 

The timing belt was actually off a tooth (advanced) when I bought it...that's the first thing I did was put it back to where it should be and now I'm trying to see what fuel I should use. The belt will get replaced soon and I'll adjust the valves when I replace the belt. I jumped the service connector when setting the timing and made sure it was warmed up (fans kicked on and off). Also replaced the spark plugs, cap & rotor (loctite on rotor screw).

 

It has 150k miles and you can't believe it has carbon build up? Why not. That thing should run on 87. You can run the timing at 10 BTDC with no problems other than lost power.

 

I have no problem believing it has carbon build-up at all. There must be a lot if a car designed to run on 87 needs to be run on 93. Makes me unhappy

 

i would also change the fuel filter...could be getting to much air and not enough fuel. So it might be running real lean,hense the pinging. Have u smoged it yet?

 

No, not yet. Deadline is friday, but that's not going to happen.

 

it would tell u alot about how the car is running. Here in L.A they test and if doesnt past u dont pay. Maybe u can do that,and did the guy mill the head by a chance. I would do a compression test to find out.

 

Compression test was normal and he said the motor has never been opened up. I'll probably get it inspected next week, maybe that'll tell me something.

 

did u test or did he? The car has to be starved of fuel. Do u have any cel's?

 

I tested it before I bought it. I've been getting 33-39 mpg depending on AC usage and city highway driving, which I'm very happy with. It does the rich smoke thing above 5K rpm (the few times I go there) that I've read is normal. Never any cels. Next step is the fuel filter...that's usually one of the first things I do when buying a new used car, just haven't done it yet.

 

well good luck bro,let us know how it works out for you. PEACE OUT!!!

 

No...PEACE OUT to you brother

thanks for the chat

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">You can run the timing at 10 BTDC with no problems other than lost power.</TD></TR></TABLE>

Is this true? NO other problems other than lost power?