Im asking this because I did an mpfi swap to my car about a month ago but I never check the ignition timing to see if it was right. At idle when I listen to the engine, it makes a noise I can only describe as a "hiccup". And it has been harder to start lately. Today I pulled the #1 spark plug and it looked like the outer electrode was white, and the base was covered in black soot. I have a manual that says the ignition timing is 16-20 degrees, yet a lot of posts I find people are saying it's 18. I want to purchase a timing light now just to be safe. What do you guys think?


[Modified by b16awarrior, 2:49 AM 10/24/2002]

 

Either way, you'll need to replace those plugs! I would only use OEM plugs. (NGK) They work the best, trust me.

Next thing to do is check out the timing - buy the timing light (no fancy advance ones, just a regular basic one) and check and see where your timing is lined up.

The OEM timing should be at 18BTDC I believe, but it doesn't really matter where it's at to be honest. Run the lowest octane fuel on that motor as well. Chances are you are running a little on the rich side due to the MPFI swap, so advancing the timing a bit might make up for all that extra gas, plus give you a little more low end power.


[Modified by MrTodd, 8:08 PM 10/23/2002]

 

Im confused now. I thought when your car's ignition timing was advanced you had to run with 91 octane. I know my car is running rich, but does running rich allow you to advance the timing and still use the cheap stuff?

 

Oh, and by the way, I am using the OEM NGK's. And can anyone explain the "hiccup" noise when it idles for more than a minute? The idle drops so low sometimes that I think the car is going to turn off. Im not sure what is wrong.


[Modified by b16awarrior, 3:26 AM 10/24/2002]

 

Sorta. The more gas you throw in that combustion chamber, the longer it takes to ignite(if all of it even does ignite). So the richer you run, the less chances you'll see detonation.

Stay away from running rich tho - with the stock motor (d16a6, or d15b2) the compression isn't very high, so you can get away with advancing the timing by 2 degrees, and still running the cheapest pump gas. (IF your motor is nice and clean on the inside) Probably the only way you'll stop running rich with a MPFI'd D15B2, is to get an adjustable FPR - otherwise you'll be running through spark plugs and O2 sensors too often.


[Modified by MrTodd, 8:30 PM 10/23/2002]

 

any throttle adjustments? is the IACV in it's right condition?(no CEl codes?)

 

I'm having a similar problem, usually this would point to problems in the ignition system (i.e. spark plugs too worn, wires kinda dead, bad cap/rotor..)
But I've just barely replaced the cap&rotor, put in NGK wires, and NGK plugs. When I increase the idle speed a bit, it seems to stop the hiccup quite a bit...

I'm thinking of 2 reasons:
1- Idle speed is too low, meaning anything less than 750 rpm.
2- Something is dying in the ignition system (as mentioned above)

Unfortunately my stock tach seems to drop to 0 when it's at the idle speed, so I don't know what I'm idling at. First make sure your idle speed is correct, if it still hiccups, then you might need to replace some ignition components... My guess is that it's hiccuping because the plugs aren't too happy.

 

Wouldn't platinums be bad for a d series engine? I mean there would'nt be a real performance benefit, at least that's what I have heard. And yeah, last time i put a light in there, I could see the the top of the pistons just fine, and they looked like you could eat off of them. Is it bad to run lean for a long time? If so, should I get new plugs and advance it all the way or would the logical choice be to purchase a FPR?

 

Oops. I see you have an Si. And one more thing, if I changed my header to a 4-2-1, will this help with my problem? You know, maybe get the exhaust gases out of the motor better since I think the stock header sucks. The 92-95 d16z6 exhaust manifold looks way more efficient.

[Modified by b16awarrior, 3:58 AM 10/24/2002]


[Modified by b16awarrior, 4:00 AM 10/24/2002]

 

When you advance the timing you run rich..

 

im a little confused...
are the plugs white? which means ur running lean
or are they black.. meaning ur running rich...
remember to look at the electrode itself.

 

Advancing or retarding ignition timing has nothing to do with running rich. The point was made that if your car is running rich, you can advance timing to compensate for it and not detonate on lower octane fuel.