MembersPage/BlownHemi

After some consideration of my options, I'm almost set on going with VEMS for engine management. Anything that's cheaper is far less intelligent, anything that's more intelligent is also more expensive.

The car is an '89 S13 200SX w/ a built CA18DET engine. 1809ccm, 4 cyl, turbocharged, intercooled, multipoint sequential FI, COP ignition.


Note: the size and chronological organization of this page is getting out of hand, unsuitable to get overview (which is required for support). Split to several pages, and make most of the pages thematically organized. See MembersPage/DavidBlades example.

recommended at least:


Starting attempt

Unsuccessful, won't start. Symptoms:

Will attach screenshot of triggerlog in the evening, but as described, one white pulse, and it's over, comms break.

At 115200 and 57600, triggerlog freezes communications.
Sometimes there are 2, 3 sectriggers recorded, sometimes even a primary, well, it's a game of luck, depending on the position the engine stopped last time, I suppose.
The triggerlog is functional at 19200, but secondary pulse count was incorrect. In the one issue I've tried, 167 sec pulses were counted between two primaries. There must be 90.

Suggestions received from VEMS support:

* no change, but RS232 comms definitely problematic
* when COM port in Win Dev Mgr is configured at above 19200, VemsTune data reception is laggy, intermittent. E.g. I keep moving the throttle pedal, and every 3 seconds, there's a 1 second pause in the gauge. A power cycle of the ECU fixes this, as it falls back to 19200.

Ideas:


Q/A With Vems Support

Lets start with the basics, to diagnose why you might be having problems getting the engine started, could you provide:

Please upload these files with appropriate names to FileArea (or other storage space) and link here

I'll review and make some suggestions on how to proceed (and what to adjust). Thanks!

Best regards, Dave


Re: Q/A With Vems Support

Hi Dave, my problems at the moment are twofold:

Do I need to fix #1 before I can address #2? I have the Nissan stock CAS, that's 180 sectrig pulses per crank rotation. This is the highest frequency of all CAS's out there that I know of. Do I need higher RS232 speeds than 19200bps to make an accurate triggerlog and/or vemslog?

I don't think my ECU resets during cranking, I get continous quick updates of the Vbatt value in VemsTune during cranking @~8V, I'm guessing serial comms would disconnect, and the gauge would freeze, if the ECU would reset due to low voltage.

I can make logs tomorrow afternoon, if 19200bps is enough.

Kind Regards,

Balazs


Hello Balazs,

A1. Serial comms over 19200 is not needed at cranking, if your serial communication is working stable at 19200 no need to worry.

A2. We are not aiming to actually start the engine just yet, first we need to diagnose if everything on trigger side is working properly

A3. ~8v during cranking is definitely way too low, attach a big fully charged battery to front with proper jumper cables (no booster) as suggested by me earlier.

To get to the bottom of this:

I'll review and make some suggestions on how to proceed (and what to adjust). Thanks!

Best regards, Dave


Hi Dave,

I've uploaded a .triggerlog and .vemslog with the Nissan_SR20_16-4-8-12 trigger defaults (powercycled the ECU after burning). They are of the same cranking run.

http://www.vems.hu/files/BlownHemi_11454/

I didn't do the prohibit_h thing, I just pulled off injection and and ignition in the engine bay (it's quite quick and simple in my case, just 2 connectors next to each other). I've charged my battery, last time it was seriously depleted from all the cranking I did before. It's now cranking ~9.5V, as you'll see from the vemslog.

After I made the logs, I've also cranked a long one with injection and ingition in place. I took a few deep whiffs afterwards from the tailpipe, and it's as if I can detect a faint smell of gasoline.

What's a realistic cranking VE value? Is the cranking pulsewidth in the ballpark for this configuration, conditions (~25*C)? 1.8 liters, 4cyl, 1000cc low imp. injectors?

Also, for some reason, from time to time, I find that injector settings change from Simplified to Traditional. Simplified was my setting, but I've checked after the logged cranking, and again it has gone back to Trad.. I've set it back again to Simp. During the logs it was still Trad. Does the Nissan_SR20 default or something else implicitly change this setting?

The triggerlog look quite different from when I've tried with my own settings. Without the Nissan_SR20 defaults, I had lots of white columns with some blue columns, now it's just blue+green pairs, no whites. I'm guessing this setting changes internal trigger behavior substantially. I've looked at quite a few pages in the wiki and almost all of the manual during the research phase, and didn't find any details about these trigger options. It's just a basic "if you have this, select that" guide. I'm not expecting a deep system level documentation about the workings of the trigger circuit/software, but a bit deeper explanation might aid in self-diagnosis for those of us who are not just pure petrolheads, but engineers as well.

Thank you in advance for any help,

Kind Regards,

Balazs


Hello Balazs,

I have reviewed your files:

No need to worry about any fuel related now, first im trying to diagnose (remotely) if the basic requirements are in place, this is needed before all else.

Thanks! Best regards, Dave


Hi Dave,

I've added two new .vemslogs, dated 18:20-ish, made in Safe Mode. I don't know if recording a triggerlog and recording a vemslog are mutually exclusive, if they are, probably that's why the previous one doesn't contain anything, both are from the same cranking, when I've activated trigger logging.

Forgot the triggerlog in safe mode, I'll make one tomorrow.

P.S. one change I've made for these two logs is, I've doubled my req_fuel. When I've configured it initally, I halved it, just like I read in the guides, in preparation for doubling the VE resolution this way, but after halving the calculated req_fuel, I forgot completely to actually double table/cranking VE's. I've turned off safe mode, and it definitely smells like fuel now. Still won't fire though, pity, I really though that was gonna be it.

Kind Regards,

Balazs


Hello Balazs,

Best regards, Dave


Hi Dave,

I've uploaded a triggerlog made in safe mode, dated 09.26.55.

Kind Regards,

Balazs


Hello Balazs,

Safe mode is enabled, good; but your triggerlog does not contain any engine cranking, reminder of what is needed:

Thanks! Best regards, Dave


Hi Dave,

maybe I'm doing this all wrong then. Since I don't see any Start/Record or Stop/Save buttons, I assumed by opening Tools/Record_Triggerlog the recording starts, and closing this window stops and saves it to the auto-dated filename. Is that how recording works, or am I missing something?

Kind Regards,

Balazs


Hello Balazs,

Opening the triggerlog dialog starts the recording, correct; But without you cranking the engine (while the triggerlog capture is running) trigger pulses are not captured. If needed you can Stop and Start the recording with Start V3 and Stop V3 in left bottom corner.

Best regards, Dave


Hi Dave,

so, the problem with the triggerlog was the following. 8-10sec cranking wasn't enough. That's why you didn't see the cranking in the previous triggerlog. I had to crank for 13-14secs, for any data to actually show up, even data from 6-7 seconds before. When I stopped at 10 seconds on previous occasions, this didn't happen, the log stayed empty except for the safemode indicators. I've now uploaded a triggerlog that actually contains something besides the safemode indicators, I hope it proves useful.

Kind Regards,

Balazs


Hello Balazs,

I have reviewed: v3.3_u011454-2016-08-07-16.25.11.GOOD.triggerlog, looks good; we now have confirmed good trigger operation (of both primtrig and sectrig) on engine.

Its now time to advance to the next tests:

Best regards, Dave


Hi Dave,

Regards,

Balazs

Addendum:

Thank you for the help so far!

I'll check continuity from harness to the idle solenoid again, lacking a better idea. But since the stock ECU had no problem starting and holding idle with this same valve, I suspect a misconfiguration, but I have no idea where. I've connected it to InjH? output, configured it to InjGroup? 7 channel on the dialog. It show up in the Idle config and the Outputs dialog correctly as well.

Addendum2:

I've taken out the Injector H pin (EC36-pin17) from the connector, grounded it, RPM jumped up by 500. So, IAC hardware is working correctly. There's something not right on the VEMS side.

It is configured to InjGROUP? channel 7 non-inverted. I'm assuming, maybe wrong, that this is the Injector H ch.128 output, EC36-pin17?

Reference DC curve is set to 95% all the way from cold to warm. Changes here have no effect.


Hello Balazs,

Great to hear you were able to complete the steps in order and to have it resulting in a running engine!

I would recommend one change still:

Regarding the idle control, if you post a vemslog of engine running (which also has your current configuration) and link here i can review what might be causing the issue.

Best regards, Dave


Hi Dave,

I've uploaded my current config and a vemslog dated 2016-08-15. My TPS is at 3%, I've gapped it with a washer so that I don't have to keep my foot on the pedal. Otherwise, it is otherwise calibrated correctly at 0-100.

Thank you,

Kind Regards,

Balazs


Hello Balazs,

with the TDC after the trigger outside of the recommended range you might have some timing inaccuracies, i would strongly recommend to adjust it.

I have reviewed your vemslog (v3.3_u011454-2016.08.15-17.36.42.vemslog) and was able to pinpoint the source of your IDLE problem, you have assigned the idle valve to INJgroup/7 (which is good) but you have not assigned a pin to this group in Base setup->Injector outputs visual (this needs adjusting) in your case you should tick the last checkbox to assign INJgroup/7 to EC36-pin17.

From general running review it seems your engine is running quite uneven on cylinder 2 (see Injector calibration view), i suspect there might be some injector unbalance, HV leak, plug cable not properly connected or coil failure.

Best regards, Dave


Hi Dave,

Thanks, I'll add that tick tonight.

What do you mean by unevenness on cyl2? Sudden low/high spike in AFR or RPM, or some other in/out variable? What should I look for in VemsTune and/or the log? I'd like to diagnose this myself by swapping components around, like coils/injectors/plugs.

(I can hear aslight unevenness, a misfire-ish event every now and then at idle, heard it on the the old ECU as well.)

Also, there is an option in the Secondary trigger settings I don't understand:

Kind Regards, Balazs


Hello Balazs,

You can check the cylinder balance in View->Group->Injector Calibration (or press ALT+5) the columns in the gauge represent relative power per cylinder (normally on a smooth running engine they should be around even).

The sectrig setting Ignore sec.trigger pulses above RPM, keep this its at recommended value, it will not impact timing accuracy. The secondary pulses are used to determine what initial window we are in (by pulsecount) but due to the high frequency of these pulses they are a lot of wasted time at high rpm, so they are ignored above 3100rpm; timing reference is always the primary trigger (4 window) not the secondary (used for check and sync).

Best regards, Dave


Hi Dave,

I'd like to ask a few more questions, if I may.

Uploaded log and cfg:

v3.3_u011454-2016.08.17...

Thank you,

Kind Regards,

Balazs


Hello Balazs,

The individual power gauge represent difference in rpm period between ignition events on a smooth running engine (all even) there should little to no difference. The numbers above the columns represent cylinder number, but only if you set them up correctly in Ignition outputs visual. Make sure you selected the correct firing order for your engine and that your output channel going to coilX (on cylinder Y) has Y in front of it. If not use the rotate buttons next to real cylinder order to shift.

Have not reviewed your vemslog yet, as all of the current Q's seem to be related to either some hardware problem (misfire, injector flow difference, coil problem or other) or tuning.

My suggestion would be the following:

Best regards, Dave


Hi Dave,

I have

(On my previous build, Cyl 3 (the deviating one) showed signs of running hotter, that runner of my tubular manifold rusted much quicker at the head flange on Cyl 3 than the others.)

Thank You for any other suggestions you may have, I understand this issue is now out of the VEMS domain.

Kind Regards, Balazs


Hi,

Update: swapped injectors to a brand new set (these are high Z 12ohms, deleted the resistors). The old set had an unreliable injector. Idle is now noticeably nicer. Cylinder imbalance still there.

Question: can the imbalance be caused by that cylinder down on compression?

Thanks, Regards, Balazs


Hello Balazs,

Did you also adjust the tdc after the trigger and recalibrate the timing with timing light like i suggested ?

Regarding the indivdual power difference still present. This can be caused by anything that might be causing a power difference, like:

I hope these hints provide you with enough information to narrow it down.

Best regards, Dave


WORK IN PROGRESS


Aligning VEMS with the engine:

POWER

See FSM page EF&EC - 80 for wiring diagram.

(ECCS = ECU in Nissan CA18DET terminology)

Original
The ignitions switch goes into the ECU, there it activates a low-side switch, which operates the ECCS relay. The ECCS relay supplies the actual 12V power to the (rest of the) ECU.
 colorfunction
ECU pin 16R/Bswitches on/off the ECCS relay
ECU pins 49,59,109B/W ECU power supply
ECU pin 45B/R Ingition switch, ign. on: 12V
VEMS
VEMS has no provisions for this mechanism, it just needs its switched 12V, the end. We need to add this simple switching circuit ourselves, like this. All that is needed really, is a switching transistor.
VemsPower.jpg
This is a quick and easy way to adapt one system to the other. Probably not the best one, but certainly better than powering VEMS from the Ign.Switch signal directly.
For now, I'll just solder this directly into the wiring, cover all leads in heatshrink, and then ducttape the whole thing. DIYFTW! :)
(Maybe a capacitor for filtering Ign. switch bounce? Gate resistor if a FET is used? TBC).
VemsPower2.jpg
MAIN INPUTS

Air metering

Original
MAF
VEMS
4bar MAP + IAT (already have both)
MAP will be mounted externally, close to the IM, shortest possible tubing
5V supply comes from the ECU
IAT is a BMW type, res./temp diagram TBC
Wiring changes - MAF
Cut off MAF at the pigtail, it's 3 wires (12V, GND, signal). Use these for the MAP sensor, which also takes 3 wires (5V, GND, signal).
Wiring changes - IAT
Need to look for a suitable wire that will be freed up, and goes to the throttle body area, where the IAT will be located.
  • 1 or 2 wires? Ground wire could be spliced into the ECT/TPS ground B wire, which is right there. Only 1 additional wire needed then.
  • Idle switch? 2 wires from ECU, and idle switch is not used in VEMS, but TBC.

Crank angle, cylinder pos.

Original
mounted on EX cam, disc has two concentric rings for two optical pickups with OC outputs
(pulled on up ECU side)
ca18detCas.jpg
Outer ring has 360 slits
Inner ring has 4 windows w/ lengths in slits: 16, 12, 8, 4
CHECKED no. of degree pulses for Window slits High/Low (H L H L H L H L) 16 74 12 78 8 82 4 86
CHECKED 16 pulse window corresponds to Cyl 1. According to a few Internet sources, Rising edge of 16-slit window is 60 BTDC. Which sounds logical.
For primary trigger, will either use:
  • Rising edge w/60 BTDC
  • Falling edge w/28 BTDC (window length is 16 sectrig pulses, that's 32 crank degrees)
Secondary trigger will use Nissan special trigger option, sync Cyl#1 to Window longer than 13 sectrigger pulses ("Ignore pulses shorter than" option)
cas4.jpg
VEMS
using the same CAS with the "nissan 360 degree secondary trigger" option
Wiring changes
The TDC (inner ring) and the angle (outer ring) signals are both wired double into the ECU, on pins 41+51, and 42+52, respectively. Probably a good idea to solder these together, before crimping it into a connector.
JDM swap guys and RHD M/T guys should check their wiring/colors on FSM page EF&EC - 82. It's a bit unclear, the TDC and angle signal has the same wire color (G/B). Label them before you cut.

Engine coolant temperature

Original
NTC regular type, 2.5kOhms at 20*C, 300Ohms at 80*C
VEMS
using the same

Throttle position sensor/switches

Original
Idle switch, closed when pedal released
TPS ~1kOhms - ~9kOhms for fully released, fully pressed, respectively
VEMS
using the same, except idle switch is not normally considered (although it can be connected to a free analog input of course). Mixing in idle switch (pulling to GND, but through 10..20k) into TPS signal (for a voltage "step") is superfluous and should not be justified, TPS has all the information without this anyway.

Knock sensor

Original
1 channel, piezo type, mounted between #2 and #3, shielding grounded to ECU ground
VEMS
using the same

O2 sensor

Original
N/A, stock narrowband removed, Bosch 4.x installed
TBC 4.2 or 4.9
TBC for any special requirements for an extension cable, twisting, shielding, etc., or just simple wiring
VEMS
using the Bosch 4.x WBO2 directly
MAIN OUTPUTS

Ignition

Original
Individual coil on plug, ECU outputs logic 5V signals for each cyl.
  • 5V signals go to power transistors mounted in engine bay, these drive the individual coils
VEMS
using the same, putting out 5V logic signals

Injection

Original
lowZ injectors with dropping resistors mount in engine bay
VEMS
need possibility to drive either highZ or lowZ-s injectors, so "active flyback" option required
Q: do low-Z injectors still need dropping resistors?

Idle Control

Original
no idea, probably the same as any other Japanese vehicle from the same era, 2pin terminal, 12V PWM
VEMS
using the same
  • I would suggest to replace it with something simpler - i.e just one PWM valve. The original system contains 4 separate items: 1) A mechanical valve that closes when the coolant heats up; 2) A mechanical screw for adjusting the base idle; 3) A PWM valve that only changes the revs about +-200 rpm when hot (too little to use just that); 4) A valve for extra air when A/C kicks in.
  • Thanks for the info, didn't know the idle valve was too small, now I get why all that extra mess is there. I've planned to get rid of the on/off AAC (no A/C) and the mechanical air regulator, too.
    • How about running both IAC and AAC off the same PWM signal? Would that work and have the capacity to regulate idle across the whole range? (I don't want to buy/build anything extra I don't necessarily need.)
    • Or, is there a cheap, off-the-shelf or junkyard idle air valve from another make/model that would work in place of the mech. air regulator? I could install that in the parking lot.
      • Seems like a BMW M43-M50-M52 idle valves would almost work, except one of the 2 air hose diameters are not the same, as the CA18 air regulator. Would have to stretch the silicone over it.
Most engines have suitable idle air valve:

Fuel pump control

Original
low side switch
VEMS
using the same
Q: any "modern" features, like 6V operation, PWM closed loop w/ fuel press. sensor?

Questions so far:

Flyback type: which one for lowZ, lowZ+R, HighZ?

ETC: for 2wire ETC, where is the 2nd wire connected?

Triggers:


Questions round #2

How difficult to add inputs later, oil pressure, EBP, VSS, etc. ?
I need a WBO2 extension cable. Any special requirements for this? Get one from ebay, or build it myself?
Does VEMS use free-air cali. or the built-in resistor?
What is the current version of the genboard ? 2016 v3.8, but schematic is same as v3.6 (apart from some protection on EC18)
IAT, MAP, TPS, CLT... ground? = EC36/26 branch of the "ground-fork"
Injector flyback compatibility table
Injector 30V flybackactive flyback
High-ZYY
Low-Z+RYY
Low-Z in PWM modeNY
::Active flyback (8ch or 4ch) can be added later (2 hour work), but maybe better to get the harness and engine right, instead of ECU modifications
Tach. signal - Nissan RPM gauge needs a voltage level. Any DAC outputs, or should I just add a properly sized RC filter to a PWM output, e.g. EC36 pin 4?
On second thought, it may be PWM, FSM is foggy about this. Maybe I'll try without the RC first. Is there a test-mode to play around with the RPM signal before the engine is running?
Purely what-if, theoretical questions
How complicated to convert to 6-cyl later?

Switched 12VsB/W, 49, 59, 109all come from ECCS relay, connected inside the harness
Grounds50, 60 and 110, 20,07,108,116these go to body ground in 2 groups

GROUND LAYOUT (ORIGINAL HARNESS)

ECU pinfunctionproposed usagenotes
50<br />60CAS GND<br />Air.Reg. GND<br />Shdg. CAS<br />Shdg. NBO signal<br />Shdg. KS<br />Shdg. MAFtie to Sensor GNDgoes to Engine Ground 1
10 20 107 108 116FICD GND<br />Ign. Trans. GND<br />Inj, Idlevalve, NBO heater returns, probably<br />seems like a Power GNDuse as Power GND TBC how thick? goes to Engine Ground 2
26MAF GNDtie to Sensor GNDoriginated from ECU
30TPS GND<br />ECT GNDtie to Sensor GNDoriginated from ECU
[Orig. Ground Wiring](HUGE)

Wire assignments (that I already know):

ECU pincolororig.funclocation of remote endVEMS pinnew functioncomment
1R/WIgn.1d/cEC36 pin 35 TTL output req.
2R/YIgn.2d/cEC36 pin 33 TTL output req.
3R/GIgn.3d/cEC36 pin 34 TTL output req.
11R/LIgn.4d/cEC36 pin 36 TTL output req.
101W/BInj. 1d/cEC36 pin 7  
110Y/BInj. 2d/cEC36 pin 19  
103G/BInj. 3d/cEC36 pin 8  
112L/BInj. 4d/cEC36 pin 20  
41G/YCAS TDC strobesd/cEC36 pin 27primary trigger
51""""""
42G/BCAS degree pulsed/cEC36 pin 13secondary trigger
52""""""
18B/Pfuel pump relayd/cEC36 pin 15 low-side switched
54Y/WIdle sw. -TB left sideEC36 pin 28  
27G/BMAF signalfront of engineEC18 pin 6  
26BMAF groundfront of engineTBD was common with other B pins in Nissan ECU
57Yidle switch +left side of throttle bodyEC36 pin 2IAT 
48LG/RTPS supplyd/cEC36 pin 29  
38LG/BTPS signald/cEC36 pin 1  
30BECT+TPS groundat TBEC39 pin 5sens. comm. GNDQ
7Y/Rtach. signald/cEC36 pin4 voltage level or PWM?
106SBidle control valved/cEC36 pin 17idle control valvepicked Inj_H channel for this (PWM)
23Wknock sensord/cEC18 pin 1  
28L/ORECT signald/cEC36 pin 14  
16R/BECCS relayd/cn/a own switching circuit, see top of page
45B/RIgn. switchd/cn/a own switching circuit, see top of page
58RConstant 12Vd/cn/aEC36 pin 23FLYBACK, direct path to Injector common (resistors common)
29WLambda sensord/cn/aEC18 pin 13WBO2 (Nernst) signal 
115Llambda heaterd/cn/aEC18 pin 18WBO2 heater 

New wires to be laid for new functions

 LBWBO2 pump+WBO2 areaEC18 pin 9
 YWBO2 pump-WBO2 areaEC18 pin 7
  'TBD' MAP +5Vrear of intake manifoldEC36 pin 28
  'TBD' MAP signalrear of intake manifoldEC18 pin 6

Wires still needed for new functions

Oil pressure. sensorwill add later
EBP sensorwill add later
Water temp. sensorwill add later
Water pressure sensorwill add later

Wires freed up (no equivalent function on VEMS, or not YET assigned to a VEMS function):

ECU pincolorfunctionlocation of remote endcomment
6G/YA/C relay? a harness around the exhaust sidelow side switch
17?Check Connector? inside
32?Check Connector? inside
33?Check Connector? Inside
43ORstarting signal? key, probably
44G/ORneutral switch?probably merges into harness around firewall
46L/GA/C switch? inside(A/C switch + blower on) -> 0V
47?Check Connector? Inside
53Y/GVSSfrom gauge cluster
56?A/T control unit?could be missing
111PUPR control solenoidnext to ign. power transistorslow side switch
115Llambda heater?O2 orig. location

[NOT YET FINISHED]