o2 wont cycle

[wdawson4]

I am a little stuck right now i recently replaced my o2 sensors before i had my engine swapped with a rebuilt one and when we started it up to start tuning the o2 wont cycle???? Now when i open the throttle (step on the gas) it reads but other than that it only reads in between .02v - .06v... i grabbed another o2 sensor to make sure that it was a good o2 sensor and it does the same thing(reads when i step on the gas but it wont cycle at idle).

Without this issue fixed i cannot get a tune which i despretly need mod list is below


dsmlink v3
850's
bc 272
evo III16g
blow thru 3" gm maf
wally 255 rewired
aeromotive fpr

please someone help me

 

[Absit]

Are you not logging wideband or can I just not find it? What's your wideband say?

 

[wdawson4]

Not logging wideband as far as i know i asked for it to be done but never got done i am very new to tuning so if i knew the importance of this before i would have checked. Oh and i am pretty sure my wideband is pegged to the right as much as i can remember i havent looked at it in about 2 hours and its late i will check for sure tomorrow.

 

[Absit]

Well, if your wideband is "pegged" lean that would explain why your front o2 sensor is stuck showing lean.

 

[wdawson4]

So i went outside and once it gets to operating temperature the wideband fluctuates in between 16.9 and --- (pegged to the right) on the gauge. Which mean that at idle i am extremely lean at idle but how do i correct this.

 

[TSITurbo95]

Some car's like to idle lean, atleast mine does. And did you try replacing the o2 sensor?

 

[wdawson4]

Yes they I have used an OEM Mitsubishi o2 sensor and a parts store Bosch o2 sensor and the both are identical.

 

[TSITurbo95]

Do you have link? Is the keep o2 in open loop enabled? Possible stuck injector? Bad afpr? Boost leak?

 

[bNasty]

i too am having a similar issue my o2 wont cycle i only notice it moves when i tip in the throttle

 

[wdawson4]

Do you have link? Is the keep o2 in open loop enabled? Possible stuck injector? Bad afpr? Boost leak?

i have link v3, lock open loop is disabled, i couldnt imagine injectors being stuck they have less that 500 miles but i can pull, afpr reads above 40 (dont have liquid filled gauge so needle shakes), zero boost leaks

 

[TSITurbo95]

And after reaching operating temp, the o2 still flat lines? What psi did you do a blt to? Any way to change out the gm maf with either another one, or a 1-2g maf?

 

[wdawson4]

i too am having a similar issue my o2 wont cycle i only notice it moves when i tip in the throttle

How does it affect how you tune your dsm.

And after reaching operating temp, the o2 still flat lines? What psi did you do a blt to? Any way to change out the gm maf with either another one, or a 1-2g maf?

The log i posted was at operating temperature but yes it stays flat, blt was done at 20 psi, and i may be able to find a gm maf from a local dsmer or my local pick and pull.

 

[9!'clipseDOHC]

Your CombinedFT's are at 29%. They should be around zero. What brand fuel injectors do you have? The first thing you need to do is make sure your globals are properly setup. Are you sure your base fuel pressure is 43? Did you set it with the car running at normal operating temp with the vac line pulled and plugged or with the engine off and the fuel pump activated via v3? Both of those methods are correct. If you did it another way it could be off. Hopefully once the globals are properly set your o2 will start to cycle. Then you need to adjust you injector deadtimes to get your CombindedFTs to zero.

 

[wdawson4]

I just checked my afpr and it actually at 37 on the gauge so i need correct that .

 

[9!'clipseDOHC]

That 6 psi difference alone will raise your injector globals from -47.3 to -43.2 making your car run richer (which it needs). Report back and let us know how this affects your o2 sensor.

 

[kthackst]

I thought the base fuel pressure for a 1g is 37 psi at ATM. I am almost certain of that. 2g is to be set at 43psi.

http://www.dsmtuners.com/forums/newbie-forum/359811-1g-base-fuel-pressure.html#post152093700

Ok 1g manuals are to be at 37psi.
1g auto, 1g NT, and all 2g are to be at 43psi

 

[wdawson4]

Set fuel pressure at 43 and i think its cycling log below

wideband reads 14.6 - 15.0 at idle at operating temp

 

[9!'clipseDOHC]

I thought the base fuel pressure for a 1g is 37 psi at ATM. I am almost certain of that. 2g is to be set at 43psi.

http://www.dsmtuners.com/forums/newbie-forum/359811-1g-base-fuel-pressure.html#post152093700

Ok 1g manuals are to be at 37psi.
1g auto, 1g NT, and all 2g are to be at 43psi

That is what the factory fuel pressure regulators are set for. Once you have an AFPR and ecmlink, you can run whatever pressure you want.

Set fuel pressure at 43 and i think its cycling log below

wideband reads 14.6 - 15.0 at idle at operating temp

Yes your 02 is cycling now and you are in closed loop. That is good. However your CombindedFT are still anywhere from 12% to 27%. You never answered my question about what brand 850's you have. We need to make sure your globals are right (you were using 792 as your injectors and now I see 738) before adjusting your deadtimes until your CombindedFT's hover around zero.

 

[wdawson4]

Im sorry alot of this is greek to me as i am a noob when it comes to using dsmlink i have fic 850's.

 

[9!'clipseDOHC]

Im sorry alot of this is greek to me as i am a noob when it comes to using dsmlink i have fic 850's.

Did you get them new with the flow chart? They should flow about 847 or so, so input that along with 43 psi in the global calculator and use the number provided as your global injectors. Then use the injecor deadtimes to get your combindedfts to 0 while keeping your airfloperrev at .25. If your combindedfts are positive, add deadtime and if they are negative, subtract deadtime.

Hope this helps!

 

[bsbllfit7]

so i too am having the problem of my o2 not cycling. Just switched to a wideband and it is simulating the narrowband signal now and still no cycle at idle. Once i get moving it cycles no problem. I do have a stock afpr and i think that may be the issue. My combinedft reads 0 at idle but once i start driving they go up and down. I think its weird im not getting a cominedft at idle but idk. What do you guys think. Oh and ill post a log here in a few