I have a B18C SI-R/GSR and when I went to go and do a compression test I noticed that the plugs were a light grey color. I know they should be a red-brown color, and I figured that the light grey was a sign that I was running lean.

I currently have a AEM CAI w/ DC JDM 4-1 w/ 2.5" Carsound w/ Apex-i WS exhaust. I also have a B&M FPR.

After doing a search, I found that raising my fuel pressure may solve the problem temporarily. Is it just a matter of raising the pressure, then driving the car, and checking the color of the plugs? Any reccomended fuel pressure settings? I am currently running stock timing with stock fuel pressure.

I just need to get by until x-mas, and that is when Jeff at IB will be tuning my new S100!

I am also running a stock 1993 CX fuel pump, time to upgrade? Clogged injectors?

Any advice is welcome.

 

what fuel pressure are you running at right now?

.......personally I'm running about 51psi, with B18C; I/E, ITR cams

Also using an ITR fuel pump because my si pump maxed out at 52psi (now the ITR can pump out 60psi easily )

 

ditto

 

I am running about 37 psi. What do you guys think?

 

Up. Any suggestions?

 

you should be around 40-41 psi,because my singlecam was at 38 and was running a bit lean also so try it at 40 and see how the car reacts to it,mine is currently set at 40 and is a bit better

 

I will go ahead and bump the fuel pressure. I guess the only way to find out if I am still running lean is to pull the plugs, right?

 

DYno with wideband O2... that's how you find out if you are running lean. That is the only way to tell for sure.

 

Yeah I know. I have to hold off until x-mas time; then I will get the Hondata S100 and have Jeff at Import Builders install and tune it.

Until then I need to address why my spark plugs are a light grey color. I just bumped my fuel pressure up to approx. 40-41 psi. I didn't have time to pull the plugs (too much homework), but I am going to go ahead and drive around for the next couple of days, and then pull the plugs this weekend.

I guess if this doesn't work, I should look towards maybe buying some injector cleaner, then upgrading to a bigger fuel pump.

Thanks

 

Hmm it is hard to tell if your running lean if your just checking plugs, if takes time for them to show the condition they are under. You can run it rich it won't hurt you too much just unplug you vac hose off your FPR and take a look at the pressure reading. This is your approx pressure at WOT which for a Civic Si for example should be like 42-46psi stock. I imagine your going to need alittle more than that with your mods, your pretty much shooting in the dark with out a EGT or a O2 sensor other than your stock one. Run a ~50psi should keep you safe until you get your tuning done.
-James


[Modified by Zenki James, 1:18 AM 11/7/2002]

 

I know how to adjust the pressure up and down, but when I pull off the vacumn hose to the FPR, I normally cover it with my finger tip. So to figure out what my estimated WOT fuel pressure is, I should not plug the vacumn line, and read what it says on the fuel pressure gauge?

The plugs themselves are practically brand new. They have only been in the engine for about 1000 miles. Is this maybe to early to tell if I am running lean or not?

I've heard of a EGT, I was going to purchase one if I went turbo, but I really don't know what it is. Does it measure the temperature of the exhaust?

When you say aprox. 50psi, you are referring to WOT, right? I just bumped it up today to 40psi at idle, but I have yet to check what it is at WOT.

 

You know... it's funny: My plugs have a brownish-grey colour to them and I was always told that it is correct that way. If what you are saying is correct, then I have been running too lean for several months even though my A/F ratio is stoich.

It would be okay to run rich for a while, but running lean is not good at all.

 

I don't really know if we are in the same boat. My plugs didn't have any brown on them, the electrodes were all a light grey color, that is it. I guess if your A/F gauge reads stoich, then you should be fine. I would be careful if you have the Autometer A/F gauge, I have heard that it is no more then a few blinking lights; in other words, it is not very accurate.

Anyways, anyone else have some .02?

 

according to ngk's site...light tan/gray should be fine.

http://www.ngksparkplugs.com/techinf...aq/faqread.asp

-Rod

 

Thanks Rod for the link, I just wish they had some posted examples.

On C-speed Racing they have a "how to" on doing a compression test, and they show what a good plug looks like. My plug didn't really look like their plug. I really don't think my plug is the right color.

Hey Rod-What fuel pressure do you run on your GSR motor?




[Modified by 93SSPHatch, 10:43 PM 11/6/2002]

 

Actually I don't have an adjustable FPR...stock. Do you have a pic of ur plugs? I don't think the pics on c-speed are too clear. Maybe it's my monitor. But i think if ur running lean...it'd be noticeably white or with white spots present.

-Rod

 

I actually don't have a picture of the plugs(no digi camera ) Yeah, I know that the C speed racing pic is not clear, but I also have a Haynes manual that shows the various kinds of spark plug reading. The picture they give for a perfect plug is not what I have.

I am going to try and borrow my neighbors camera this weekend and take pics. Maybe I will be able to post them (once upon a time I figured out how to post).

 

Thank god I don't rely on an Autometer gauge for my information. I had the car tuned to stoich while it was on a dyno using a wideband O2.

And, if I were to install gauges in my car I would use one of the latest (and expensive) A/F gauges that come with the improved O2 sensor.