z32 rich and non matching dual wb during warmup, random miss when warm

[xlr8]

anyone up for a challenge? though it may be something simple ive not found in my researching. lets hope so, but im desperate and out of ideas what my problem could be. hopefully someone can see something in this log. im very noob to tuning like this so please forgive my long story. but its been a long slow budget based restoration. 1990 z32 tt 5speed swapped, including manual cam swap, dual innovate, feature pack and flexfuel. all emissions are deleted. Im a diesel mechanic but definitely not a tuner, but i dont want to bring the car to a tuner until i get these issues fixed, (mainly because of potential fuel in the oil from the strange rich warmup, and the random miss and idle search when warm) I put in 1000cc injectors (bigger fuel pump, lines, regulator etc) along with the nistune and had a rich condition during warmup and i would have to scale back the multiplier to make it not flood until warmed up, then when warmer and idle dropped, a random miss occurs, non identifiable by doing cylinder cutouts. (no matter which cylinder i cut, the miss was gone or at least undetectable) and the idle searches a bit. i literally have to sit there and change the multiplier it as its warming up to keep it around stoic. but the weird thing is one bank is always richer than the other until a certain temp (around 140 F). at that temp its like a switch is thrown and the banks match much closer to each other and much less rich, but still have to watch the wideband and change the multiplier as it warms further. i thought the maps may be wrong, then i messed up and tried putting factory maps in fresh and had to send the ecu to matt to straighten out. ( i think i selected wrong maf also but its fuzzy what i might have done near a year ago) but it was still doing same thing after reflash. i had already replaced the alt harness during 5 speed swap, and all new engine and injector harnesses with the nistune and the 1000cc's. i suspected a bad injector because when i got them and tested before install, one wasnt clicking i had to tap it forever to get it working. so i bought some denso 850 injectors {and 300 degree rails) had sent out and tested and cleaned and they tested great "mint deluxe". but still same problem after install. right turbo started smoking massively so the car had to sit for months waiting for funds. covid hit us so i threw on some new gsp 600's and i started searching for what could make banks so far off, looking at everything mechanically i could think of that could affect one bank only. (now that i also ruled out turbos) plugs were less than 500 miles on them, coils are new as of last week. new o2's. engine holds 5 lbs boost test, for a few minutes no problem and currently builds 16 lbs easily. i had the a/c empty because i had the entire dash out cleaned evap and heater core, so i decided to charge the a/c, and now i have a clue to the missing issue at least. when the a/c is on it runs great at the raised idle, burns stoic no miss and no longer searches for idle!! so i removed and cleaned the iac but no help it still misses and idle searches through warmer temps. huge thanks to anyone with any ideas !! hoping you can see something simple that makes me feel stupid haha !!

[Matt]

So you went from the 1000CC to 850CC and now 600CC (or are GSP coils? Google didn't help here)

Can I see the tune currently running? That way I can run it past the logs

So 140degF (60degC) is the switch over temperature?

Will check out the LHS vs RHS injection time

What does the fuel pressure look like during this?

Strange with the AC on that affects things. Does the log attached have with AC on and not?

[xlr8]

850 cc injectors.

(the gsp600 are knockoff jwt turbos a local company sells. sorry about that)

140° is just where the engine jumps to a more normal a/f ratio and the banks are closer to the same readings, it appears to continue the warm up routines, and drops as it should fully warm. but the random miss and idle surge increases as it leans itself out during warming up further.

i will send you the tune in a seperate reply, im not at my computer at the moment.

have a digital fp guage, it stays constant 43 at idle.

if i remember correctly, i turned the a/c off and on at end of the log. it is indeed strange. with auto temp on, the idle is perfect, no missing, and a/f's barely move.
the a/c does not fix the pre 140° mismatched a/f ratios though.

i can do another log showing the a/c fix better.

note* i did suck out the tank and put in fresh 91 octane gas before installing the 850cc's , but i have not used any e85 yet. i have read that california gas has around 10% ethanol in regular gas but i never saw the content analyser register any. i dont know if that matters or not, or if im just doing something wrong just thought i would mention it.

[xlr8]

attaching ecu image. hopefully this what you mean by "tune". sorry I'm still learning.

[xlr8]

just watched the log i sent, my description of problem and what that log shows is horribly wrong. i should have watched before posting, instead i described what i have been seeing previously. i apologize, but it does show how the banks dont match a/f good at all and how rich it is while warming up. i will check my oil and if not too diluted i will do another warmup log, with a/c on and off a couple times, then i will leave on at the end and hope this car doesnt make a liar out of me again haha.

[xlr8]

this car just loves to give me a hard time !! i might have coincidentally found part of the issue, was logging warmup and idle never dropped as normal. first time i saw this happen. i clamped off the air regulator hose and it dropped, and of course this also showed me i never had the base idle set correctly on the biss screw. still a random warm miss, but afr are better now with a quuck base idle adj and raising the TIM a few i will change the oil tomorrow and do a cold start log with regulator bypassed. middle of summer in cali it will hopefully cold start good without it. thanks for all your help matt.

[xlr8]

cold start log today with air regulator bypassed still shows very rich and mismatched, but doesn't become closer to 14.7 until near closed loop. unlike the fully warm run yesterday, the bank afr never seemed to match through all temps. i cycled the a/c quite a few times for this log and the miss seems to go away, but even then the mismatched bank afr's remain. this car is all over the place. any suggestions are welcome. thanks.

[xlr8]

log attached

[xlr8]

hi matt sorry if im bugging you. at very least can you please suggest a map fix to keep the ecu from dumping fuel so bad during warmup? i pretty much built the whole fuel system around the nistune and flex fuel package working, but i cant seem to get any normal readings from this old car. every warm up routine seems hit or miss on being consistant from the previous one. i would love to be able to rule out the ecu as my problem before i keep reduntantly testing everything else. thanks you so much.

[Matt]

Okay I've had an initial look through this and your maps have cleared out the temperature enrich. About 80degC it stops using it

Apart from that I don't see any major issue in the tune file, assuming you are stoich at cruise and not hitting the end of your maps on boost?

Still need to go through the logs and there is a crap load to read through and process on this thread. So it needs a good half hour to go through the logs etc properly. I'll do that tomorrow, since been swamped this week

[Matt]

Okay these are very long logs. So I've got a lot to go through

2020-08-15 15_26_58-Nistune [Z32(VG30DETT) Z32 AC on injector drop.png

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.
Flicking through this. Turn on the AC and the RPMs drop, so results in some fluctuations to AFRs

After AC turned off we see AFRs at 12.8 quite rich. However the injection time is the same as before the AC was turned on, and RPMs are the same. Something else going on there it seems?

5:05 of this log shows a similar thing

At 6:30 start seeing oscillation of AFRs and the RPMs going up and down a bit. Not from the tune/ECU since injection time is steady

2020-08-15 15_32_36-Nistune [Z32(VG30DETT) osc.png

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At 10:00 your AFRs go lean back to 14:7 when AC on and then afterwards. Strange since the injector time is still the same as before. Its like the load from the AC on and then afterwards affects how things are running. Some type of glitch, but we are not seeing a variation in injector time, only AFRs. Seems to indicate mechanical/electrical

2020-08-15 15_34_46-Nistune [Z32(VG30DETT) Z32 AC lean.png

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At 20:00 we see AC makes not a huge amount of difference. Slight increase with MAF/RPM and no change with AFRs. This is once temp over 80 degC

2020-08-15 15_38_34-Nistune [Z32(VG30DETT) Z32 80degC warmed AC.png

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One thing I will point out. We only see injection time LHS in the log. What does RHS look like if you include that in consult channels?

The whole time, injection time sits between 1.7ms and 1.9ms. Adjusting TIM would not affect this that much. Your latency is 850us (0.8ms) out of this. So the ECU is only controlling 0.9-1.1ms out of this between startup and 80degC. Something doesn't seem right here, but its not showing on the LHS injection time

[Matt]

2020-08-15 15_44_13-Nistune [Z32(VG30DETT) Z32 temp vs AFR.png

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First log shows that as temp increases, so does AFRs

However your temp enrichment table is also all 0's

Imagine if it was factory values, then it would be richer at cooler temperature values, and then as it gets warmer would maintain the same AFRs. Put that table back to factory values in this case

If all still fails, put in the factory 370CC Z32 injectors and reset the maps to stock. Check it all works okay with those injectors. Trying to get back to the factory setup where possible will help eliminate issues. Also recheck all grounds etc

Also I've noticed that your battery is quite high for idle (around 13.5V-14V). Its not over 14V which is okay, but just seems a bit on the high side. Would expect about 12V

[xlr8]

great info. yes being able to monitor both banks injection would help me greatly. but i cant find anywhere to turn on rhs. where is the setting? thanks.

[Matt]

When you connect to consult you get a list of things to view/log. If you don't see this then right click on the desktop (inside Nistune) and then select Channels from the pop up context menu.

Then select Injection Time (RHS) if available for the Z32

Did you have wideband in both LHS and RHS exhaust pipes? We only see one wideband reading in the log files

[xlr8]

ok i will start with the most current topic and try to work my way back through the conversation. thanks again matt this is my car and not a customers, so you dont have to feel rushed here, not to mention everything is covid locked down i cant take it many places anyway haha.

- i am only able to select rhs OR lhs, but not both at the same time for some reason. not sure why. but i was able to check on both o2 sensors.
- yes the wideband is in both pipes and my log playbacks shows them both recorded. attaching pic hopefully you can see them somehow on your end.
- yes i had to zero all the cold start enrichment it was so crazy rich with it on. but with my problem of continual leaning out while warming, it would have to theoretically be programmed backwards to add more fuel when warmer instead of colder. if i put it back to factory it just dumps even more, and good oil here now is close to $10 USD a quart from covid gouging, and im at least on my 5th oil change now trying to keep gas out of the oil while diagnosing. i will put it back when i get this fixed for sure.
- my stock injectors were junk and arent re-useable. they came out with crumbling plastic housings. but i feel confident injectors are good as the previous new 1000cc's i had in there when the nistune board first installed had same rich until warm and mismatched banks issues. ive swapped coils and plugs to opposite banks a couple days ago with no change. so i can rule them out.
- i feel good about the 13.8 /.9V idle charging voltage, its what we test all vehicles for in my line of work for minimum charging. its around 12.5v on my agm with key on engine off. pretty good state of charge for a non flooded battery. i also keep my cars on a trickle charger also if sitting for longer periods.
- thank you so much for looking at the logs, i think your on to something with the lhs injection time being stable and the rest of the crazy stuff happening. sadly it looks like i will have to log the rhs seperately as i cant figure out how to select both at the same time. but that might be a huge clue if it is also stable.
-attaching pic of log playback with both wb readings.
thanks again !!