E85 back to Pump 93

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rn240sx
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E85 back to Pump 93

Post by rn240sx »

So about 5 yrs ago or maybe a bit more i switched to E85, running a Emanage Blue, i upped the injector chart +35% at idle and during boost to compensate for the E85 conversion.. Kept the same Walbro 255LPH fuel pump, same 300zx fuel filter, same Nismo 615cc injectors… All has been good for the 5 yrs and just about a month ago like an overnight deal, literally, i go to crank up the car and its running PIG rich, wideband 02 reads 10 solid at idle and stays there until i start driving… While I’m cruising it reads its normal 14.7, come to a stop and wideband goes back to pig rich 10 and idle is somewhat hesitating… here and there have to blip the gas pedal to lean it out and let off and back to 10’s… It stays that way until the coolant temp reaches 160 deg where then the wideband will now read 14.7 at idle and cruising..
When i get to work or home, i manually turn the cooling fans ON to cool down the motor and literally when the coolant temp reaches 160F, the wideband again, DROPS to 10’s and idle starts to get a bit jumpy…
I have played with the motor for days and it seems to be consistent with its rich mixture when the motor is cold but once the motor reaches 160+F it seems to run its normal a/f…
When i noticed this start to happen a month ago i logged into my emanage blue and went into the injector chart and pulled the fuel down at idle from +35 down to about +15 but no change in a/f mixture.. Still RICH at idle and wideband reading 10’s .. So i pulled all the fuel out and now sitting at 0 on the charts as if i was back to 93 pump gas but again, still no change in a/f, still sitting in the 10’s at idle..
So after about 2 weeks i thought maybe some bad E85…???? So i got the fuel tank down as low as i could get, put in about 3 gallons of 93 and drove a few days letting it mix thru and went back and got 3 more gallons of 93 and still same issue.. Wideband reads 10’s at idle until the motor is warmed up past 160F then it idles perfect at 14.7 … Once i get back home from work, coolant is at 180-190F … a/f is at 14.7, smooth clean idle.. Turn the fans ON and watch the needle slowly drop, just as that needle hits 160F, the a/f literally DROPS down to 10 and the idle starts to be bit lumpy and just stays there…
So.. my question is WHY THE F*CK is this motor going that insanely rich when the motor is COLD or just as it drops below 160F…. Its never done this before, i know its rich on cold start normally and wideband reads in the 12’s on cold start and within a minute or two it will lean out to 14.7, but to stay in the 10’s until the motor is at ~160F…??
I know my motor and its never done this before so something is not right here..
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Re: E85 back to Pump 93

Post by hotbox240 »

How old is the 02 sensor?
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Re: E85 back to Pump 93

Post by rn240sx »

How old ... Lmao .. So old I can't remember when I purchased it literally ..!! All I know is that it's an old PLX wideband O2 with narrowband output for the stock ecu ..
I took out the oem one and out this one it's it's place and wire it up .. It's been there for prob 10+ yrs easy ..
not sure if it's gone bad but the motor responds to what it reads .. When it's reading 14.7 the idle is smooth, when it reads 10 flat it feels like it's gargling in fuel and wants to stall out and when it does stall out It won't start up again because the chamber is flooded with fuel and I have to wait like 20 minutes for it to dry out before it starts back up
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Re: E85 back to Pump 93

Post by hotbox240 »

Stock fuel pressure regulator? Maybe it's gummed up with E85 gunk? Did you pull out injectors and look at them?
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Re: E85 back to Pump 93

Post by duncan351 »

Check to see what water temps your ECU see's during these different water temps. Especially when 160 degrees and under. This is to confirm water temps sensor is still within range and report back.
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Re: E85 back to Pump 93

Post by rn240sx »

Speaking of water temp sensor I did read about that while doing an internet search about this issue about how it could be stuck in cold mode until it gets to operating temp ..
So I read the fsm and it showed what resistance it should be at what temps and it read as if it was ok..
Cold motor it read 1.8k ohms .. As the motor warmed up the resistance was increasing (ohms was dropping) accordingly until the motor hit 200F where the resistance got down to 260 ohms. So the water temp sensor is working as the motor is warming up and cooling back down ...
The next thing I read was to check the fuel pressure just before the fuel rail to see if the fuel pump is pushing the right amount of fuel pressure according to what the fsm shows at ~34 psi ... With vacuum at the fpr. Then shut the ignition off and watch the fuel pressure to make sure that it holds it for a while .. If the pressure leaks out quickly then there is a leak somewhere ..
I also read a bad/leaking injector... Spark plug not firing could also lead to a rich condition at the wideband ..
My next check is the fuel pressure to make sure the pump isn't pushing out too much fuel when it's cold then seems to work "fine" after it warms up ..?!!?
I guess one step at a time right ??
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Re: E85 back to Pump 93

Post by duncan351 »

That's great that the sensor is working correctly but how do you know that signal has made it all the way back to the ECU? You can perform an ohm test on the two wires from the ECU. Also want to do the same for the O2 sensor signal which can alter AFR's. If all this checks out then its my opinion that you may want to look at the ECU itself. I had a similar problem and after doing the exact testing you are doing it came down to the computer went bad. I believe it was leaking capacitors inside the ECU. I had to send my computer along with a good working one to JWT for him to transfer all the parts to replacement ECU.
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Re: E85 back to Pump 93

Post by rn240sx »

Hmm .. You have a point there, I never checked it at the ecu harness. I had my meter at the sensor itself, when I get home I will check those readings at the ecu and update you
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Re: E85 back to Pump 93

Post by rn240sx »

So i checked the ecu pins where the Water Temps Sensor wires are connected and checks out fine... It did the same at the ecu pins like it did directly at the sensor... So if its water temp sensor related then it has to be in the ECU..

Next thing i did was check the fuel press. They say that a fuel pump can go bad and just start pushing too much fuel causing an overly rich condition. So i grabbed my fuel press sensor, hook it up, wire it up, turn the ignition ON (no start) and the fuel press hits 40 psi at 1st, then drops to 34 psi... held there for about 5 seconds while i was about to turn the ignition ON to see if the fuel pressure spiked while the engine was running and all of a sudden the fuel press gauge spiked to 100 psi...... WTF..?? So i turned the ignition off, turned it back ON and again the gauge spiked to 100 psi... So after a few ignition on and off attempts, the gauge seems to get stuck or wants to hit 100 psi... Shut the ignition off .. Pull the fuel pump fuse to start up the motor to burn off the pressurized fuel in the system and get it empty again for another attempt... Done, now the fuel system is empty.. Leave the fuse OUT and turn the ignition ON and again, the gauge swings right to 100 psi ... Now i know its the gauge and not the system.. So needless to say my fuel press sensor has failed on me while trying to troubleshoot this issue .... What bad luck huh..??
So.... now i have to try and find a cheap fuel press sensor that uses the same "sendor" that i have now because i really dont want to pull that fuel line out to put in another sendor
I will keep you guys updated.. !!
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Re: E85 back to Pump 93

Post by rn240sx »

So I got a new fuel pressure gauge, upon ignition the fuel pressure goes to 40 psi then drops to 37 psi .. And holds there, I start up the motor and wideband reads 14.7 for about 30 seconds then goes pig rich to 10's while fuel pressure remains at 37 psi solid ... I blip the gas pedal and the fuel pressure also jumps as well ...
So the sensor is after the fuel filter right there at oem location and before the fuel rail inlet ...
I trend the ignition on and let the pump prime ... Got 42 psi then dropped to 38psi ... Shut the ignition off to watch the fuel pressure to see if it goes down due to a possible leak ... Nope, fuel pressure was solid at ~37 psi for 15 minutes ...
So I can only imagine that it may be the injectors .?? Maybe they are sticking open longer during each pulse ??
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Re: E85 back to Pump 93

Post by duncan351 »

So what's your MAF voltage reading after starting the car and it begins to go rich? Record your readings. Then check the O2 sensor voltage reading as it richens up? You already checked coolant so we can weed that one out based on your info you gave us.
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Re: E85 back to Pump 93

Post by rn240sx »

So... i went out to get the voltage readings from the maf sensor harness and as i grabbed the wires to move them to pinch into them, the motor stalled out... So i cranked it back up and started to move the wires ever so slightly to see which is causing it, and it seems like the black wire (center) when i moved it slightly (at the harness side of the MAF fitting) it stalled out and when i moved the white wire (top) same spot the motor wanted to stall out... Guessing we have a loose connection inside the harness fitting..?? Maybe enough to cause this overly rich condition..??
These wires were cut and spliced YRS ago when i converted to a Z32 MAF and where i cut the wires they were really close to the maf fitting, i was trying not to cut too much back, so i did the best i could .. but we are talking like 13 yrs ago ... I was younger and dumber and just wanted the sh*t to work.. So, i guess i will order a new pigtail off ebay and re-splice it PROPERLY this time :-)
Again, will keep you updated..
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Re: E85 back to Pump 93

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So i got the new MAF pigtail ... Wired it up and immediately saw a difference. This time when i cranked the motor up and the second it fired over, the rpm's went to 1500 rpm and the idle was SMOOTH.... Where as before with the old maf pigtail with loose wires, when the motor fired over, the rpm's would never go over 1k and the idle would be rough and lumpy for about 10 seconds before it would smooth itself out. So that was an improvement... As far as the wideband readings, it took longer for it to get that rich but this time it did not drop into the 10's as fast but slowly dropped from idle 14.7 to 11 flat... which is still overly rich but slightly better... While it maintained 11 flat on idle... coolant temps got to about 140 deg F where i hit the gas pedal and kept the motor at about 2000-3000 rpm for about 20-30 seconds then released, then the wideband went up to 14.7 and maintained there for about 3 minutes. Coolant temps reached 180 F and fans kicked on, motor cooled off, wideband still around 14.7
So the only thing i can do is tomorrow or during the weekend i will do a cold start and let it warm up for about 1 minute then take her out for a spin to see what she does and hope that the wideband stays in the 14's while at lights ... If the problem comes back then i will check the MAF voltage and the narrow band voltage from the wideband 02 because it does both outputs...
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Re: E85 back to Pump 93

Post by duncan351 »

Great job man. You're getting closer.
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Re: E85 back to Pump 93

Post by rn240sx »

Ok.. sorry i am about 8 months LATE... My job transferred me out of state for work the 1st week of September... Been living in an apt for 8 months ... But i am finally back home.. Back to this rich issue....I cranked up the car and getting same issue, PIG rich 11.0 from cold start to about 165F... then it leans out to 14.7, just wanted to make sure the same issue is here since ive been gone for 8 months...
I un-plug the coolant temp sensor harness and fire up the engine and it runs as rich as 13.5 then about ~130F it will raise back to 14.7 and sit there perfect...
The next day i plugged the harness back in and fired her up and same rich issue again.... 11.0 at cold start until about 165F when it leans out to 14.7
The next day same thing, un-plug the harness and fire her up... 13.5 till about 130F and leans out to 14.7.....
The wiring is testing out fine... With ignition ON i get 5V from pin 2 to ground.. With ignition OFF i get continuity from pin 1 to ground... so i know the harness is correct.
I put in a NEW wideband sensor ... same issue... Swapped out the MAF that i got from a buddy, same issue...
So i checked the coolant temp sensor AGAIN... cold it was 2k ohms.. at 120F it was at .7 ohms but it kinda stayed at .6 ohms for quite a while before eventually dropping to .2 ohms at 190F... And again.. this is reacting like a coolant temp issue because when the temp reaches 165F it leans out and when the temps drop below 165F it goes pig rich... It only makes sense but when i checked the sensor itself it checks out to be fine... UNLESS... When 5V is applied to it... maybe its getting stuck in "cold" mode until the coolant gets hot enough to kick it out of cold mode..?? And maybe when i was watching it and it was lingering at .6 ohms for quite a while was the sign that its getting stuck there...?? Everything points me to this coolant temp sensor but it all seems to check out fine for the most part..
I guess only one way to find out is to get another one and swap it out and go from there...
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Re: E85 back to Pump 93

Post by duncan351 »

Are you running stock O2 sensor still for the computer? If so, what's your O2 voltage reading from cold to warm?
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Re: E85 back to Pump 93

Post by rn240sx »

No, the wideband 02 i am using is the Bosch LSU4.2 which has the narrowband output wire for the ecu and the normal wideband signal for the PLX module... But i can check those voltages and compare to the fsm...
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Re: E85 back to Pump 93

Post by rn240sx »

duncan351 wrote:Are you running stock O2 sensor still for the computer? If so, what's your O2 voltage reading from cold to warm?
OK... so upon COLD start the O2 sensor (narrowband output from wideband) reads .44V upon cold start with wideband reading 14.7, then stays solid for about 30 seconds when the O2 voltage jumps to .66V then holds there for about 5 seconds then jumps to .89V and stays there........ Wideband gauge at this time starts to DROP from 14.7 to 13.5, 12.5, 11.2 and holds there.. O2 voltage still solid at .89V and both stay there until the coolant reaches ~170 deg where the O2 voltage drops to .30 to .50, probably staying more in the .4V area... Then the wideband starts to lean out back to 14.7
So from this test it seems the narrowband voltage climbs up to .89V and sends that to the ecu, then the ecu richens up the mix, the wideband starts to read more fuel and shows accordingly.. Then after the narowband voltage drops after ~170 deg, the ecu gets that signal and lets off the fuel and the wideband leans out as it should be reading...
This obviously is NOT normal so i can assume that maybe the narrowband portion of the sensor is bad..?? Maybe its getting stuck in cold mode and sending a high voltage to the ecu which in tern is causing my wideband to read rich which it IS...
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Re: E85 back to Pump 93

Post by duncan351 »

rn240sx wrote:
duncan351 wrote:Are you running stock O2 sensor still for the computer? If so, what's your O2 voltage reading from cold to warm?
OK... so upon COLD start the O2 sensor (narrowband output from wideband) reads .44V upon cold start with wideband reading 14.7, then stays solid for about 30 seconds when the O2 voltage jumps to .66V then holds there for about 5 seconds then jumps to .89V and stays there........ Wideband gauge at this time starts to DROP from 14.7 to 13.5, 12.5, 11.2 and holds there.. O2 voltage still solid at .89V and both stay there until the coolant reaches ~170 deg where the O2 voltage drops to .30 to .50, probably staying more in the .4V area... Then the wideband starts to lean out back to 14.7
So from this test it seems the narrowband voltage climbs up to .89V and sends that to the ecu, then the ecu richens up the mix, the wideband starts to read more fuel and shows accordingly.. Then after the narowband voltage drops after ~170 deg, the ecu gets that signal and lets off the fuel and the wideband leans out as it should be reading...
This obviously is NOT normal so i can assume that maybe the narrowband portion of the sensor is bad..?? Maybe its getting stuck in cold mode and sending a high voltage to the ecu which in tern is causing my wideband to read rich which it IS...
I experienced a similar issue years ago when i was still running tuned stock ECU. I'm assuming you are getting your O2 voltage values from what the ECU sees. If this is true I would disconnect the narrow band signal and check with the signal voltage from the O2 with it disconnected. There is a chance the voltage readings are good coming from the N.B signal. If its operating correctly then your problem is with inside the ECU.
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Re: E85 back to Pump 93

Post by rn240sx »

duncan351 wrote:I experienced a similar issue years ago when i was still running tuned stock ECU. I'm assuming you are getting your O2 voltage values from what the ECU sees. If this is true I would disconnect the narrow band signal and check with the signal voltage from the O2 with it disconnected. There is a chance the voltage readings are good coming from the N.B signal. If its operating correctly then your problem is with inside the ECU.
Ok i cut the wire from the wideband module so NO O2 voltage gets to the ecu... Cold start the O2 voltage is .44V and immediately starts to climb to .5V then to .6V then to .7V then sits at .88V ... Wideband gauge did the usual and went RICH 11's.... Both sat there all the way to ~190F when my fans kicked on... cooled down the motor back down to ~175F... Wideband still reading 11's and O2 voltage still at .88V, so im guessing since the ecu is not see'ing O2 voltage, it keeps dumping fuel as a "safety" ....
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Re: E85 back to Pump 93

Post by duncan351 »

Correct.
rn240sx wrote:
duncan351 wrote:I experienced a similar issue years ago when i was still running tuned stock ECU. I'm assuming you are getting your O2 voltage values from what the ECU sees. If this is true I would disconnect the narrow band signal and check with the signal voltage from the O2 with it disconnected. There is a chance the voltage readings are good coming from the N.B signal. If its operating correctly then your problem is with inside the ECU.
Ok i cut the wire from the wideband module so NO O2 voltage gets to the ecu... Cold start the O2 voltage is .44V and immediately starts to climb to .5V then to .6V then to .7V then sits at .88V ... Wideband gauge did the usual and went RICH 11's.... Both sat there all the way to ~190F when my fans kicked on... cooled down the motor back down to ~175F... Wideband still reading 11's and O2 voltage still at .88V, so im guessing since the ecu is not see'ing O2 voltage, it keeps dumping fuel as a "safety" ....
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Re: E85 back to Pump 93

Post by rn240sx »

So the next question is... do you think its the ecu or the narrowband voltage from the O2 getting stuck in rich mode for whatever odd reason up to that point which is the coolant temps reaching ~175F ... which may have nothing to do with it (maybe coincendence) or it could be until the exhaust gas temps reach a certain temp then the 02 sensor backs off its Voltage to the ecu ... which at that point the wideband starts to lean out ... as it reads correctly when the narrowband voltage drops off back to .44V ....
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Re: E85 back to Pump 93

Post by duncan351 »

Sounds like the ECU. Capacitors failure if I had to guess. If you have a JWT ECU then you can send him a replacement computer along with yours and pay them to move their board over to the replacement ECU. This is what I had to do. The wide band and narrow band signal are reading correctly and accurately from your description.
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Re: E85 back to Pump 93

Post by rn240sx »

duncan351 wrote:Sounds like the ECU. Capacitors failure if I had to guess. If you have a JWT ECU then you can send him a replacement computer along with yours and pay them to move their board over to the replacement ECU. This is what I had to do. The wide band and narrow band signal are reading correctly and accurately from your description.
I still have my jwt ecu in my tool box... i removed it and put the stock ecu back in along with the emange blue.. so that i could have more control over fuel & timming ... cause we all know how RICH his tune is and how much timming they pull back under boost which we all know its to keep the motor happy (to a point) under boost but at the same time, you loose precious hp because of it..
i guess... i can remove the stock ecu and put the jwt ecu back in and leave the emanage blue in as a piggy back & just zero out the fuel and timming so that its not adjusting anything ...
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Re: E85 back to Pump 93

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duncan351 wrote:Sounds like the ECU. Capacitors failure if I had to guess. The wide band and narrow band signal are reading correctly and accurately from your description.
I am trying to understand how you believe its the ecu in this case because the narrowband voltage is sending a high voltage to the ecu which in tern richens up the mixture which the wideband is reading correctly ... once the narrowband voltage drops back down to normal voltage at ~.44V, then the wideband starts to lean out and stabalize at 14.7 .... So in my mind its the O2 sensor that is starting off at .44V (wideband reading 14.7), then as the narrowband voltage increases to .88V the wideband starts to read rich... as expected, then after the motor is warmed up... the narrowband voltage drops to .44V, then the wideband starts to lean back out to 14.7, so i see it as the narrowband portion on the O2 sensor is "stuck" in cold mode... i thought it was the coolant temp sensor based on where it was going from lean to rich and rich back to lean but that sensor was swapped out and no change so the other culprit was the O2 sensor ... and from what i am reading, the O2 sensor is sending that high voltage to the ecu the entire time until it backs off then the motor starts to lean out...
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98 240sx KA-T Full built motor JWT ecu 60-1 turbo 10 lbs
14 Genesis Coupe 2.0T stock turbo w/Bolt ons
98 Supra MKIV stock twins w/Bolt-ons
2012 Frontier V6, 4-door, 6ft bed (Daily Driver)
09 Ninja ZX-6R, Full exhaust, K&N pod filters
06 Suzuki Boulevard S40
/\ all still current 8.30.20
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Re: E85 back to Pump 93

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8 months again... Work transferred me out of state again, im back home and back onto this car...

I removed the greddy emanage blue completely ... Now working off stock ecu, cold start wideband reads 14.7 and stays there for a while then starts to go lean.... then more lean.... then more lean till it holds at ~17 ... engine misfiring every few seconds... Stays that way until that magic coolant temp again reads ~170 F where the wideband goes RICH and stays at 14.7 for perfect idle ....
So with the emanage piggy back... its PIG RICH until ~170 deg... WITHOUT the emanage and stock ecu... its SUPER LEAN until ~170 deg...

So with the emanage, its dumping too much fuel at idle until ~170F .... without the emanage, its not enough fuel until ~170 F ... If i did not love this car so much ..... you know the rest but i will not give up her
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Re: E85 back to Pump 93

Post by duncan351 »

You have a chipped ECU right? JWT?
Chances are you have a bad capacitor or something like that in your stock ECU. I figure this out on mine yrs ago and sent the JWT ECU and a good used one to Jim Wolf and just paid him to move his hardware over to the replacement. I experienced the exact same problem you are going through.
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Re: E85 back to Pump 93

Post by rn240sx »

duncan351 wrote:You have a chipped ECU right? JWT?
Chances are you have a bad capacitor or something like that in your stock ECU. I figure this out on mine yrs ago and sent the JWT ECU and a good used one to Jim Wolf and just paid him to move his hardware over to the replacement. I experienced the exact same problem you are going through.
I am in the process of hunting down a Z32 maf so that i can use the jwt ecu & bypass the emanage ... Ben from jwt told me that the motor would run on a stock maf, but the idle would not be stable because it has been programed to a Z32 ... Not sure how they differ at idle because i read that both send out ~1.2V at idle .. So, again, im not sure how 1.2V from a Z32 is different from 1.2V from a stock maf ......
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Re: E85 back to Pump 93

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So i hunted down a Z32 maf. A buddy with a ka-t drove to my house and we pulled his off his car. Dropped it into my car, removed the stock ecu and emanage, put in the jwt ecu, put all the wires back to normal... Motor cranked over, idle'd perfect... Then the wideband starts to LEAN out... and lean out and kept going until ~18 where it started to misfire left and right ... Then at ~175F coolant temp, the wideband went back to 14.7 and stayed there at which point the idle was perfect ...
Stock ecu with emanage and stock maf it runs overly RICH until ~175F where it leans back to 14.7
JWT ecu with Z32 maf and it runs TOO LEAN until ~175F coolant temps where is richens back up to 14.7
Voltage from water temp sensor reads as it should from cold start to 210F per FSM .. There is NO drastic jump or change at that 175F mark to indicate its the reason why my a/f is changing at that temperature .. The voltage also drops linear to temp change so its not like its getting stuck somewhere.. its dropping as the coolant gets hotter ..
I don't understand what else it could be that is causing these issues... And i can simulate this all day long by playing with the cooling fans ... Bring the temps down to 150F and watch it go RICH into the 11's ... then watch it lean out to 14.7 at 175F ...
I don't think this is an ecu problem based on what we are seeing .. One ECU sends us this way and the other ECU sends us the other way and both react at 175F ... There has to be a sensor that we are missing ..
Wideband sensor replaced, coolant temp sensor replaced, AIT or IAT checks out, TPS checks out, Narrowband Voltage from BOTH wideband sensors (original and new one) check out, Both MAF voltages check out... Everything tested at the ecu pins and NOTHING seems out of the ordinary and all check out per FSM ..
www.shopboldimpressions.com
98 240sx KA-T Full built motor JWT ecu 60-1 turbo 10 lbs
14 Genesis Coupe 2.0T stock turbo w/Bolt ons
98 Supra MKIV stock twins w/Bolt-ons
2012 Frontier V6, 4-door, 6ft bed (Daily Driver)
09 Ninja ZX-6R, Full exhaust, K&N pod filters
06 Suzuki Boulevard S40
/\ all still current 8.30.20
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