SR20 Lean Condition

[wozrally]

Recently got a sr20. Drove 8 hours home and was a strong motor. Did a compression test at time of sale and 150 across the board.
Stock Motor, Stock Turbo, Stock pressure and vacuum.

Recently I have been leaning out at idle and at cruise according to aem wideband. I can definitely feel it too. Bogs, pops.

Under WOT my ratio is 11.3-12, decent,and builds the 7 psi.
I have good vacuum at idle. 18-20 inHg.
I have checked for any leaks and cannot find anything.
All my vacuum lines are good, my exhaust is good.
Fuel pressure is 40 psi. Grabbed my old walbro 255 and put it in too.
Only thing is a 1400 rpm idle that is wrong.
Injectors seem to fire as I removed them and they were all wet. And must be good if under WOT everything is okay? although there is pressure increase in the system under wot...

Have checked maf and its good. I switched with a buddys maf and still.
Have checkd tps and it seemed that was the problem at first as we moved it and saw it would richen up, idle would move too. We switched to his and was good for a ride back to his house. Was at 13.2 f/r at 1300 rpm. It then started leaning out again. Only thing is, it was set to .56 ohms and wot was 10.1ohms! This was the case for both tps. And his car has been running strong. My original set was .8 ohms....

We unplugged the maf and it riched out. Plugged back and leans out.
we unplugged the iacv and it really made no difference. It should have?
The screw it turned all the way down and still very lean.

I was very scared to run all the way home at this lean condition, so therefore I would rapidly gas a tad and let out in order to throw gas into it. I would run rich 12-13 like this but I would buck it all way home.

At times, it really bogs out to 600-800 rpm, vacumm to about 12in hg and is lean. Then kicks back up to 1400 rpm at 13-14 f/r.

Right now I can only leans towards the tps and iacv as they were the only parts to make any difference when altered and a leak I possibly cannot find but doesnt explain the good build up of pressure and vacuum.

Removing iacv today.

Ive searched the forums. No thread really gives a final answer that I could fall under.

ah yes I pulled the E5 ecu but no light to read codes off. No bulb no nothing.

[cotbu]

You are clueless, but in case i misinterpreted something i'll try to decipher it later. but good luck doing whatever you have planned though!

[wozrally]

Clueless, yes, capt obvious. The reason I posted!

[cotbu]

Don't mind my supertechman outfit. Do you by any chance have the coolant line running to the iacv?

[Croustibat]

1/ Never, never, never mess up with the TPS.
2/ it sounds like a small boost leak.
3/ You do adjust idle with the IACV if i remember correctly, but you have to unplug its electrical connector first otherwise you are just screwing everything up (like you already did in 1/ )
4/unplugging the MAF means going into limp mode. Dont. It is a special mode that allows you to move the car when the EMS is fucked up. You wont be able to build boost nor go above 2500/3000rpm.

5/ maybe the problem is your wideband is not calibrated.

6/ if your AFR goest near 15 at idle and steady speed ... then it is perfectly normal.

[OutlawLui]

whats your tps voltage closed?

and whats is it at WOT?

check with engine off, but power on.

Also what SR is it? s13 redtop blacktop? s14 s15?

do you have the correct o2?

[wozrally]

1/ Never, never, never mess up with the TPS.
2/ it sounds like a small boost leak.
3/ You do adjust idle with the IACV if i remember correctly, but you have to unplug its electrical connector first otherwise you are just screwing everything up (like you already did in 1/ )
4/unplugging the MAF means going into limp mode. Dont. It is a special mode that allows you to move the car when the EMS is fucked up. You wont be able to build boost nor go above 2500/3000rpm.

5/ maybe the problem is your wideband is not calibrated.

6/ if your AFR goest near 15 at idle and steady speed ... then it is perfectly normal.

I can mess with the tps as long its set back up...
I cant find a leak anywhere. Also like I said Im getting good boost and vac.
Of coarse Im not going to ride around without a MAF.. I was merely testing its function. Unplugged would lean it out at higher rpm as the ecu would not know to throw more gas since it doesnt know the air coming in...

wideband is good i believe...like i said i can definitely feel the lean condition.

f/r are 17 and above at idle..

[wozrally]

whats your tps voltage closed?

and whats is it at WOT?

check with engine off, but power on.

Also what SR is it? s13 redtop blacktop? s14 s15?

do you have the correct o2?

Pretty sure i have the right o2.. I ran great beforehand..till something is giving/gave out

s13 redtop..e5 ecu.

Im getting .5v idle and 5v wot, .6k ohm- 10kohm.. tps reads out good.

Although..I was messing with it yesterday and at one position, Idle nicely with 13.5 f/r but I cant rev it up as it leans barely touching the has. This was closer to the spec'd resistance of .45kohm
At another position (.6kohm) Im leaning at idle but able to rev it up as it richens

[OutlawLui]

Pretty sure i have the right o2.. I ran great beforehand..till something is giving/gave out

s13 redtop..e5 ecu.

Im getting .5v idle and 5v wot, .6k ohm- 10kohm.. tps reads out good.

Although..I was messing with it yesterday and at one position, Idle nicely with 13.5 f/r but I cant rev it up as it leans barely touching the has. This was closer to the spec'd resistance of .45kohm
At another position (.6kohm) Im leaning at idle but able to rev it up as it richens

That's weird, a e5 ECU is for a BLACKTOP SR isn't it?
Usually its a ECU 62

Also the s13 REDTOP & BlACKTOP use different O2's

Redtop :skinny titania 02
blacktop: Fat Zirconia 02

*hope this helps in anyway..good luck

[wozrally]

That's weird, a e5 ECU is for a BLACKTOP SR isn't it?
Usually its a ECU 62

Also the s13 REDTOP & BlACKTOP use different O2's

Redtop :skinny titania 02
blacktop: Fat Zirconia 02

*hope this helps in anyway..good luck

Omg.. Thanks! I think you might have cleared something for me. I did find the e5 is for a blacktop and people interchange them but....

Will an E5 ECU work with my early 5spd redtop? - Nissan 240SX Forums (http://www.240sxforums.com/forums/sr20de-det/40947-will-e5-ecu-work-my-early-5spd-redtop.html)

Sounds like my problem....

EDIT

Although... I am using the Fat o2... So I should be in the clear for using the e5 right?

[OutlawLui]

Omg.. Thanks! I think you might have cleared something for me. I did find the e5 is for a blacktop and people interchange them but....

Will an E5 ECU work with my early 5spd redtop? - Nissan 240SX Forums (http://www.240sxforums.com/forums/sr20de-det/40947-will-e5-ecu-work-my-early-5spd-redtop.html)

Sounds like my problem....

EDIT

Although... I am using the Fat o2...

The harnesses from blacktop redtop s13 are interchangeable

the o2 works until its heated to a certain temp. so that might not be the problem, if u run weird from cold start.

So you might want to try a 62 ecu, and from cold start see how it
runs..hope u have a friend with a redtop

[wozrally]

The harnesses from blacktop redtop s13 are interchangeable

the o2 works until its heated to a certain temp. so that might not be the problem, if u run weird from cold start.

So you might want to try a 62 ecu, and from cold start see how it
runs..hope u have a friend with a redtop

Sadly my buddy has the J4. But I should be good with the e5 ecu since I have the fatty o2 right?

[OutlawLui]

Sadly my buddy has the J4. But I should be good with the e5 ecu since I have the fatty o2 right?

i believe so, but im 50/50...wont hurt to try it though

[wozrally]

i believe so, but im 50/50...wont hurt to try it though

Hurts my wallet 200 bones for a test :-/

I see many saying yes and no but Im coming to a conclusion that it depends if they are actually switchin the right o2

[wozrally]

Don't mind my supertechman outfit. Do you by any chance have the coolant line running to the iacv?

yes coolant lines running thru y??

[wozrally]

SO ive clean the iacv, (didnt look bad, spring and shaft moved freely, also good resistance) sprayed down the maf and o2 for kicks and giggles...Still nothing.

Coincidentally I tapped the tps, unplugged the o2 and it ran great. Idle great too.

This morning I try to leave for work. Its idling higher (2100, maybe cold start) and it begins to lean out again..leans out as i barely push the gas.

I dont understand how it can go away and come back. Im totally lost now.
Everything checks out with power and resistance..Pump, Injectors, Maf, CTS, No vac leaks.

[cotbu]

I think I know what your problem is but, id like too verify with a video and some questions.
Does the idle go up and down...before it settle to a lean condition? This is typical CTS.
Not a malfunction just normal operation when certain criteria isn't met.
If this is happening what I do is block the radiator and keep the fans off until 85°c then unblock the rad, and turn on fans. the idle will settle and the afr richens up, the 02sensor is fully working now and immediately trims the fuel.

This morning I did a car that was idling with a 20.1afr 2400rpm. enthalpy tuned CAS also had 32 starts with a malfunction.

If you willing to get me that cold start video with cam/phone horizontal, we can get you unbroken half broken!

[wozrally]

I think I know what your problem is but, id like too verify with a video and some questions.
Does the idle go up and down...before it settle to a lean condition? This is typical CTS.
Not a malfunction just normal operation when certain criteria isn't met.
If this is happening what I do is block the radiator and keep the fans off until 85°c then unblock the rad, and turn on fans. the idle will settle and the afr richens up, the 02sensor is fully working now and immediately trims the fuel.

This morning I did a car that was idling with a 20.1afr 2400rpm. enthalpy tuned CAS also had 32 starts with a malfunction.

If you willing to get me that cold start video with cam/phone horizontal, we can get you unbroken half broken!

I will get some vids today. I typically start up at 1500 rpm with good f/r, a minute later it leans

no, idle doesnt really vary when i start it. It just idles high. When I move the tps..idle moves down and the ratios richen. Itll richen and sometimes it doesnt let me rev it up without leaning. Other times at a slight tps adjustment. (like .05v-.1v) I am then able to rev it up.

My fans are wired to turn on when key in the on position...

Buddy is telling about the e5 and the fatty o2 use.. That the o2 is still grounded differently if using the 62 harness. I am not sure what harness I have. When pulling the ecu I noticed the white plug that suppose to go to my cluster I believe, isnt hooked up..

another friend with a blacktop says his cluster plug is brown..

I google pic of an e5 harness and has the white plug.

[cotbu]

no if ands or butts, set the tps to .45v lock it down then swing the throttle to wide open slowly. let it go.volt should be under 4.99v

The engine needs to reach operating temperature 80°c at least once for the ecu to go into closed loop. do this at idle. disconnect your fans temporarily. let the engine idle keep an eye on the temperature. real gauge or ect via consult. If the 02 sensor is wired properly it will work. correctly is a different story. You should also wire the consult port up, it will flash codes on the cluster if no bulb is available on the ecu.

To my knowledge the 02 sensors for 62 -j4 are wired the same as far as input. ground matters none unless its not a good one.

Your dash plug should be brown, the sr dash connector is white, so the wiring wasn't completed properly.

[OutlawLui]

One simple cheap thing you can also try, just cus you never know..


Change the fuel filter to a z32

and try switching out the (FPR)FuelPressureRegulator to your friends..see if this might help. Over time the stock FPR become worn out.

*And it is normal like you said for it to start at 1200 rpm till it warms up. so iacv is good

*tps sounds good

*If the leaning out happens before the o2 reaches operating temperature than its not the 02, the o2 would only help fix
this problem.

Might also want to check the Temp sensor that goes to the ECU, not the dash Temp sensor

[wozrally]

alright so i didnt get a vid as I was so concentrated on looking at everything else BUT i was actually able to drive it to work today...

I swear its something with the tps.. I set it to .45v, resistance is a little high..1.1kohms
. This is still my buddies tps.. I remember mine reading .8kohms
I test drove around and it was running fine.
I quickly hit the gas and let off (talking about a split second hit, barely tapping) and all of a sudden it started leaning again..
Im rolling into a neighborhood and quickly hit the gas again and it "fixes itself" 0.o

I get home and let it chill, 30 min later I go test drive and its good again.
My ratios are good (14.7-15.3 cruising), good build of boost and ratios (11.5)

NOW its only the high idle which is higher than before (2100) which brings to believe the iacv. The screw is still all the way turned down.

I did just find the vacuum layout and one thing I see wrong with mine is the bov isnt getting its own vac source so maybe that will change it up a tad..

[wozrally]

one question pertaining to the iacv.. When I pulled it, I wonder if I could test it by plugging it in and turning the key and listening for the motor to kick on..I didnt hear it engage.

For my gsx I am able to do this. But for the sr , it must only engage when the car is fully on?

[wozrally]

since i hate unfinished threads...

update

I adjusted my tps according to voltage .
I did my vacuum lines according to

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My idle was still very high (2100, higher than before) but my ratios were perfect 14.7-15 .

I then did the attached. Its a ball valve. I can open it for warm up and move to 1000 when Im good to do. noe jus going to check my timing and adjust as needed ;)

[ultimateirving]

wtf is that about? just get a new iacv

[cotbu]

That actually works for helping the ecu relearn the iacv. I used to do this all the time. I'd set the IACV screw to 50%, then adjust the ball valve.
In about a week, I would open the valve all the way and the adjust idle. If I could bring the idle down too 850rpm I'd remove the valve and check timing. Most of the time I could stall the engine with IACV screw.

I should add, that you have to make sure you have no large vacuum leaks and an easy was is to pinch the pcv line, or boostleak test.

[wozrally]

wtf is that about? just get a new iacv

10$ and fixed under 10 minutes is what that is about. Simply restricting the flow going into the $125 broken open iacv.
Its straight for the time being.

[wozrally]

That actually works for helping the ecu relearn the iacv. I used to do this all the time. I'd set the IACV screw to 50%, then adjust the ball valve.
In about a week, I would open the valve all the way and the adjust idle. If I could bring the idle down too 850rpm I'd remove the valve and check timing. Most of the time I could stall the engine with IACV screw.

I should add, that you have to make sure you have no large vacuum leaks and an easy was is to pinch the pcv line, or boostleak test.

Yea see my screw is all the way down so I knew my iacv must be stuck open since I redid all my lines with new clamps and everything.
I am going to check my ignition timing and do a boost leak test in case there's a little hole somewhere... Although my vac and boost readings are great. I actually got a little more vac when I did my lines.

[cotbu]

You have to adjust the screw to about 50% so when you come off throttle and the ecu controls the iacv, there is a change in the iacv and the ecu can learn the new adjustment. Htms.

Sent from my De-bloated, & Turbocharged SIII

[wozrally]

I have found the problem.
I plugged up a voltmeter to the battery as I drove around.
My car runs good at 13.5v, any less than 13.3v and the car begins to lean. I suppose the injectors arent getting enough power. Odd thing is that I start with 14.1v and slowly begins to go down as I drive around.

I noticed the problem one night where I had the voltage drop and had my headlights on. I was at 13.1v and it was leaning. I turn the lights off and rose to 13.5v and it stopped leaning.

I notice I have voltage drop whenever I hit a bump in the road. So there must be something loose.
The battery is good with 12.6v and all connectors are secure.

Another strange part is when I have my foot on the brake, I notice my dash lights turn and the H/L RET down clicks...Thought this was for the headlights.
I feel I have the big voltage drop due to this.
I feel somewhere between these circuits it is being crossed somewhere.

TCU?

I think am going to have to take out the dash so I can see every wire. :/

I have my wiring tucked running through behind my dash and thru the center console. The fuse box is in the center compartment and off to the back to the battery.

I did find a short here to a relay I actually wasnt to sure off but was obviously added and spliced into the wires. I fixed that and check all the splicing and wrapped them good.

[StatticMyke]

I know I'm bumping an old ass thread but I found this searching for a problem I was having. Pretty much exact as the OP. Car would run lean at idle and just normal cruising. My AEM Gauge would just be bars --- across the gauge. Hit the throttle and it would drop to where it should be but once you get to cruising speed and back off the throttle you would be back to 18 AFR. I did most of the same things the OP did trying to find a solution. Didnt see any issues with voltage tho. I was letting the car idle listening to it run like shit full lean and for shits and giggles I unplugged the o2 sensor. About 15 seconds later the idle cleared up and stuck from 14-15 AFR's. Dont know if its the sensor itself but car runs much better than it has been WOT AFR's 10.6- 11.4 Cruising 13.9- 14.7. As of now Ive just left it unplugged.

Car is a s13 hatch with blacktop SR intake exhaust 14lbs.

Again sorry to bump a hella old thread but just thought I would give some input as well if anyone else finds this searching trying to resolve their issue.