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.


WORK IN PROGRESS

Subpages:


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


Hi All,

I've decided two switch from LSU4.2 to LSU4.9. Can you clear up a few things for me?

Thank you, Regards, Balazs


Hello Balazs,

Please follow the wiring instructions on (take care [LSU 4.9] has different connector [pinout]): http://vems.hu/vt/help/v3/v3_wideband_settings.html

Best regards, Dave