I'm still not convinced that my ECU NEEDs to be tuned. I think it should compensate and not be running lean. I've narrowed it down to the following...

1) Air filter - solution: ordered a new k&n

2) Spark plugs - solution: i ordered new ones in the same range, but does anyone think i should step up to one range colder? I have been running a range colder, but i'll go back down to normal.

3) O2 Sensors - solution: front one hasn't been changed since i've owned the car. rear one was changed but i had to extend the wires, possible bad connection. ordered 2 new sensors and will heat shrink new connections.

4) FPR - i found a post by Scalbert showing his car making around 260s w/ a bad FPR and all he did was change the FPR and it brought him up to 330s. i'm still running stock FPR. i have plans to install an AEM fpr, and i have a walboro 255 pump in the tank now.

comments? suggestions? i plan to do all of the above in the next week. if that doesn't solve my leaning out problem i don't know what else to do. i have a tuner waiting to install, but like i said, i think there's an outside force causing a lean condition.

 

What about timing?

Usually timing can make a big difference whether its running too lean or too rich.

Remember my dyno post? Just from changing a few numbers around on the Unichip my car ran a hell of a lot better and got 10 extra ponies.

Dunno, something else to consider.

 

well, if it's running lean right now, the ECU is pulling timing like a bitch. so pulling the timing even more is going to result in even more loss of power just to get it to run richer. still i think there is something not function right causing it to lean out. i think it's probably fuel or sensor related.

 

It's kind of hard to see if it is a fuel sensor. If it is. Check the pump, it maybe going out without you knowing. The fuel filter maybe dirty...(when was the last time it was changed?)

Check the fuel lines as well. See if there isn't a bulge or a clog. Once you get up to the fuel rail, check as well.

Then the injectors...check to see if they are all working properly.

If it's sensor related that would be bitch but you'd think they would through a code by now.

I'm not really convinced that it could be an ECU issue either.

check here for checking resistance for your injectors...regardless if they've thrown a code yet.

https://acurazine.com/forums/showthread.php?t=185909

njrzyprettyboy did this but he had CEL thrown.

Maybe a piggy back may help you out after everything is checked

 

i think it would be a bit more obvious if it was injector. it should be causing misfire.

walboro 255 fuel pump in the tank with all brand new filters/housings. it's all brand new in the back as of aug 06.

edit: yea, my worst fears. injectors. =\ i guess i'll replace those too.

 

Not necessarily, I've seen cars misfire before without codes being thrown.

Maybe check the system again...you never know. Some products can go tits up even with being new.

Could you take it to a shop and have the mixture checked...when you have time?

 

i did, i have AFR readout by every 100 RPM. it's very constant across the whole way. again, another reason i don't think its injector issue. time for an AEM FPR and dump some more gas in there.

 

I was thinking,

does your car feel like it bogs down between shift points?

I can't remember if we have coil packs or not...if we do. Check those as well.

I'll check back later with some other ideas...

 

Something wrong with ur fuel lines.. did u ever change ur fuel filter?

 

all 6 coil packs were replaced less than a year ago.

again, my entire fuel filter/housing/assembly/pump was replaced in august 06.

edit: one weird thing i noticed was that while my car is in park and idling, the car will surge once every minute or so.

 

Explain the surge....

RPMs drop then go up again?

Dunno without explanation.

 

have you checked the MAF sensor that plugs into the air box? sounds definitely like a sensor problem I'd check every sensor again and their wires.

 

Try cuting the A/C off and then see if it will still surge.?

 

dont think we use a MAF, i think you mean MAP. i was playing with the idea of getting a new throttle body bc the TPS/MAP sensors cannot be purchased seperated, but new throttles are expensive =\

 

i thought it was just the A/C cycling and i noticed it more with the louder exhaust, but it does it even if i push the system to OFF.

 

i spoke to some more gear heads, and everything is leading me to think the FPR is not operating correctly.

 

my car ran rich on the stock ecu

 

To "cleancl" :

1. I aguess I am at the same boat as you r, same symptoms occure in my car......i changed the air filter, sparkplugs, injectors cleaned, cleaned the throtle body...i dont know what else....


What do you think if ICA would have any effect ?

As well i encountered that the smell from the exaust does not smell right , so maybe some sensors, that could effect the performence?

What about catalic?


Anyhow if you come up with any ideas ...please let me know,,,and vice versa

 

im changing my air filter, spark plugs, o2s, dont think its the cat, but im leaning on bad FPR. if all that still doesn't work im going with new injectors.

 

What AFR are you seeing? I'm running lean all the time as well between 14.5 and 15.5 during low RPMs and cruising around, and it's lowest to around 13.5 at WOT. I am looking at getting an aftermarket fuel pump and AEM universal FPR. I think that should do the trick.

 

max is 15.2 lowest is like 14.2, i never see 13.5. yea i've got an aem fpr waiting to go on.

 

Wow, nice, let me know how the install goes. Also, did you get the AEM universal model? Are you going to hook up a Fuel pressure Gauge as well? If so, let me know how you did the custom adapter fittings b/c I am pretty sure all gauge fittings do not match the AEM FPR.

Thanks

 

yea i have a universal model, ill get you the part # if it works out for me, theres a local hose / fitting store by me that carries all kinds of fittings. usually local speed shops carry them too. you need AN fittings. honestly i forget the sizes, but if you just bring it in they can match up the threads, thats what i did. hardest part was getting a fitting for where the stock FPR gets removed. and the model i get has an extra threaded area to screw right in an electronic fuel pressure gauge. fairly simple install. i'll post up on it when i do it this weekend.

 

Goodluck with everything. Hope this fpr does the trick.

 

I'm thinking a bad fpr or O2 sensor. If you're concerned about injectors, I would send yours out to this place. Your injectors can be cleaned and flow tested for a lot less than new:

http://www.witchhunter.com/

 

my guess woulda been the O2 sensors

 

O2 sensors are going to throw a code though guys. If they're bad the ECU is going to know it and light up the dash. (CEL, !, and VSA)

I don't suspect the fuel filter because we don't really have a fuel filter other than the suction filter at the end of the fuel pump.

I think the surging at idle may be a different issue. If you were having mixture problems while in closed loop the ECU is going to tell you and throw a code. The surging is likely a IAC valve problem. It probably needs cleaned, adjusted, or replaced.

If you're only running 14.2 at WOT even through VTEC I would definitely say you have a problem. You should be around 13.2 with a dip to around 12.9 at 5700rpm then back up to 13.2 by 6300rpm. I wouldn't suspect the pump, fuel lines, or injectors. No one has had failures. Even when we were pushing them at 100psi. I guess maybe it could be the FPR although that seems odd too. I guess since you were planning on replacing the FPR anyways I'd start there. I'm pretty baffled to be honest. Weird.

 

hope you figure it out soon jeremy.

dang lucy got big mr steve!

 

Any updates? Still waiting for pricing from Excelerate on my AEM FPR and walbro pump. If he beats nolimit I'm ordering ASAP.

 

well, i am replacing the FPR w/ a stock oem one for now bc i'm under the impression now that the OEM one should not be running lean. will get to a dyno sometime within a week to check AFR.

 

thanks. i was baffled too, that's why i posted. i was thinking the same way as you. but i come from an electrical background, and i've seen far too many times things operating, but not functionign 100%. maybe the o2s are doing that. honestly i'm just searching for a quick and easy answer, because if it's not, then the only things it points to in my opinion are: stuck injectors (which i doubt bc if that was the case the afr/hp/tq lines would be erratic and their not, their dead smooth), bad ecu (too expensive and sounds like a headache to try to diagnose), bad motor. if it's either of the last 2, it's time to sell the car.

 

How are you monitoring AFR?

 

with a dyno for now bc it breaks it down in 100 rpm increments. i know what your think, i don't drive the CL at all now, it just sits, and only drives to the dyno, i have a 2nd car. eventually if need be i will set up a wideband o2, but who knew i would need one being n/a.

 

Keep in mind that the dyno is not 100% accurate as far as AFR either. I was at a Bay area meet and the shop hosting the event had a dyno. We strapped down my car and he did one partial run. The guy freaked out because I was running lean and he didn't want to pop my motor. I told him to do a full run as I was not hearing any detonation.

Next guy rolls up on the Dyno and guess what - his car was running lean too. Turns out that his O2 sensor on his machine was going bad and was giving bad readings.

 

Are you losing power up top where you are running lean?

 

I would definitely confirm you're running lean through a secondary source before you go too far chasing this issue. Especially if you're not showing symptoms of being lean.

 

how do you know your car is running lean?

 

we're all on the same page. right now i dont have the time to get a wideband o2 installed. so i'm going to a second dyno after changing the FPR, air filter, plugs, and o2 sensors. all of which i had already so it wasn't such a big deal.

 

i'll just cut to the chase and post my dyno charts and data logs. basically everything looks exactly like it's supposed to. AFR has a huge dip at vtec changeover, except it's in the lean range. torque curve is FLAT until about 5750 rpms. HP curve climbing steadily until about 6,000 rpms where it almost begins to flatten out. everything LOOKS right on paper except for the numbers. we didn't even redline, i pulled until 7,000 RPMs.

in short, yes, my power is dropping off in top end.

 

needless to say, i'm pretty discouraged at the moment.