Ok, heres the scoup. I have a 2002 Eco with Hahn Stage 2. Now I installed my wideband and calibrated it and all that stuff. so its working good. Now the problem is at idle my a/f is b/w 15.6-16.2. In my opinion this is way too lean. Also, even when cruising around in 4th or 5th, the car is still running around 15.2-15.8. So I decided to come on ehre and see what plugs people are using and what not. So i take out my old spark plugs and they were all White, all of them. So I went out and purchsed the 2004 Champion SRT-4 copper plugs everyone recommends. My car also runs very lean when under boost maybe dropping slightly under 15 to like 14.3-14.7. I realyl do not want to blow up my eco. so what is going wrong guys? any ideas? i am using the 32lb 320cc Accel Injectors which came with the Hahn Stage 2 Kit as well as all the fuel accessories like fuel pump and regulator etc.. Let me know ASAP thanks

thats really not that lean for idle and it is helpful to know what PSI of boost you are seeing with those A/Fs if its like 2-3 lbs of boost and your pulling out because of the A/Fs you need to see what it does under wot 14.7- 15.5 isnt gonna kill your engine with just out of atmosphere pressures

If it is still lean at WOT then you need to increase your fuel psi with your BEGI you should have recieved. You wanna try to get it to 11.5: under WOT



ASE Master Certified Automotive Technician

well, under WOT i have never even seen it get under like 13.9, no even close. and what is a BEGI? is that the UFO looking thing with the brass adjustable needle valve?

Yes the UFO looking thing is your adjustable fuel pressure regulator. You need to adjust it to increase your fuel pressures when under boost. That UFO thing you have is activated by boost and will gradualy increase fuel pressures as the boost pressures increase. It is helpful to have a fuel pressure gauge hooked up too when adjusting it so that you can keep track of your adjustments. You can get one at autozone for 20-30 dollors



ASE Master Certified Automotive Technician

i have hooked one up b4, i have never achieved the 85-90psi at full boost like the manual suggested, no matter how much or which way i have turned the brass needle. ht emost i ever saw was about 81-82psi...

Well those pressures are about right. What is the base fuel pressure at? and have you dead headed your fuel pump to see if its not the problem. And again what boost pressures are you seeing?



ASE Master Certified Automotive Technician

cruising your fuel pressure needs to be at 40 psi then around 85-90psi wot for 8pounds of boost....taken straight from the Hahn tuning manual

i have been following the hahn manual all along. i know my idle pressure is spot on what it is supposed to be. i remember i adjusted it perfectly when i first installed the kit. idle is for the silver screw on top of the FMU thing. the brass needle didnt give me too much difference in pressure. however like i said i was getting 80-82psi and WOT... not sure about cruising though. but the wideband still says lean literally all the time. however, i have an engine light on, and when i got it diagnosed, it said, fuel trim to rich.... help please

please people i need your input!! thanks

so no one knows anything???

i gave you some direction and you dont seem to wanna follow it so very likely no one wants to help because your not listening. It doesnt matter what you set your stuff at when you first installed it!!!!!!!!!!! YOU NEED TO KNOW WHAT ITS DOING NOW! if your PCM says the A/F is too rich it probably IS. You said you calibrated your wideband, well are you sure its right? As I asked before did you dead head your pump? Nobody here can waive a wand and know whats wrong with your car without you trying to help us help you diagnose it. What wideband are you using?



ASE Master Certified Automotive Technician

hi again, ok i have retested many things, such as my idle pressure is 35psi, spot on, just like the manual suggests. And yes i have calibrated my wideband just as the instructions say, it is the lc-1 with the xd-16 gauge. and it still says 15.6-15.8 at idle. I have dead headed the pump, how much psi should it be pushing? thanks

it will dead head between 80-90+/- psi but ive seen them as low as 70-80+/- and still be considered good (J-Bodies as reference however a good general reference as well). Those Hahn directions are more a reference then FACT. Everyones vehicles are a little different because of many variables. Hence the need to TUNE. I've had to run psi as low as 20 psi to get it where i wanted it @ idle and so on. have you watched to see if your psi is increasing while accelerating lately? Have you checked your vacuum lines to the afpr? If your PCM is saying system too rich its one of two things; Your vehicles IS running rediculously rich OR your pre O2 is malfunctioning. No if ands or buts about it. If the pre O2 is functioning correctly then theres an issue with your wideband. Which brings me to another question; Where is your wideband O2 located in the stream? Do you see black smoke at all? Just remember that your idle A/Fs will be anywhere between 14:1 - 16:1 as the PCM tries to maintain 14.7:1 and when cruising it will be the same and sometimes closer to 16:1 on long steady low load cruising as the PCM will go into "Cruise" to better enhance fuel economy, it will run leaner. Remember your car doesnt recognize boost so the best it will try for and this is not taking in account for forced induction is 12.5:1, mine would go as low as 11.1-12:1 under WOT stock. Add boost and your numbers go lean and you are purely compensating by fuel PSI and larger foriegn to your PCM injectors. So in saying that your car "depending" how your AFPR is adjusted will not really put you to your needed 11.5:1 until the PCM sees WOT and goes into OPEN loop and forgets about emmisions regulated 14.7:1 programming AND the fuel pressures sky rocket due to the afpr sensing boost. Following me I hope? Well again since your PCM doesnt REALLY know how to control fuel to a newly installed larger injector you need to FORCE it in while the PCM demands FULL PW from the INJs this only happens under full load or WOT in OPEN loop. Now after that short lesson i wanna ask one more question; when you are going into boost are you creeping into boost steadily or are you punching it and slamming it into boost foot to the floor? Romp on it! get it into OPEN LOOP and let the TPS go into WOT that "should" yield pretty rich conditions under boost (8psi) @ 80psi of fuel psi. Im thinking to myself and asking; didnt you get an inline fuel pump with your Stage 2 kit? You should have and should be easily able to make more than 80 psi of fuel pressure.............................................................................. if you do, is it working?



ASE Master Certified Automotive Technician

Hi, yes it came with the inline fuel pump, i was geting about a 92PSI reading when it was dead headed. I have just yesterday tried your theory of romping on it. and when i do put it right to the floorboard, it actually does get into the rich side 11-12, but does this mean whenever i want to run hard boost to put the petal literally to the metal? cause i never used too.... and i still flew...

yes like i said it will put your car into OPEN loop and your PCM will ignore your pre 02 sensor readings yielding you the ability to better richin your mixture. However you can better tune your A/Fs under all driving conditions with adjustments to your AFPR. Your limited though because of the style AFPR you have because really it only reacts to Pressure and not vacuum. There are AFPRs that do have the ability to do both but they get to be double the price and can more precisely tune your fuel pressures under the full spectrum of vacuum and boost.



ASE Master Certified Automotive Technician

well i found someone in my city with HPT tuners so hopefully he can set me up good..

there you go that will work too, good luck



ASE Master Certified Automotive Technician

thank you

also take into concideration where the wide band is located....... some wide band sensors dont read correctly when located to close to the turbo, and they deff. dont work correctly located after the cat. (dont ask, but I've seen it done)




SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

hey, i dont have a cat anymore, and the sensor is about 3-4 feet downstream of the turbo.

what it sounds like is that you need someone with HPT to change the point at which the ECU goes from closed loop to open loop/power enrichment mode... I know on the Skwirl's car, it didn't enter open loop until after 5500 rpm, and the same with our friend's turbo eco that we had all sorts of nightmares tuning until we realized that the Eco ECU has ridiculous settings for getting into open loop, and unlike most cars that can only compensate about 25% tops for fuel trim, the Eco's fuel trim compensation seems to be infinite... meaning that if its not in power enrichment, you can practically poor a gas can into your throttle body and it will still adapt out the extra fuel (not really, but I have a penchant for over-exaggeration). Of course, from what we gathered from people on here, that seemed to be an issue with 03.5 and up model years, this is the first time I've heard of a similar issue on an 02.




Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said

well i guess it can happen to anyone, every little factor goes into what your car does.. weather, driver.. etc..