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R and S sensors are brand new Bosch. I swapped those in a couple of days ago and I regapped them to approx 1.1mm per Peep's advice. That exercise had basically no effect on this performance issue as I had similar behavior before and after the replace and regap. The issue is occurring in 2nd and 3rd gear; I cant try it in 4th or 5th without fear of losing my license...
I changed the view of the logs of my post in 201, and there, in fact, no trigger error. Below are two screenshots - one right before the cutout, and another immediatly immediately the rpm dropping to 0. The spark angles do look way off vs the base tune map which is embedded in the lower right corner of each pic. I'm perplexed. Maybe overwhelming the coil and it is giving up momentarily?
MAP = 0 triggers a Fuelcut by default. Check Base Setup/Rev Limit/Overrun/Safety-->Overrun Fuelcut/Fuelcut below xx kPA.
So I think since your MAP is 0 VEMS cuts the fuel as you can see Lamba reading >1.83 / Pulse width = 0.5mS.
MAT -100°C is probably like the MAP reading a sensor or wiring issue, which doesn't help either. Or your MAP hose has a sharp kink.
My conclusion, too many parameters out of default scope. Maybe VEMS crashes because of the implausible values and displays RPM = 0.
Based on the screenshot above, I don't think it's a coil issue.
Thanks Chris. I'm hoping that a refresh of the speed and reference sensor harness helps, and your points on noise and possible grounding issues make sense.
Before running across the inability to rev over 5200 or so I had a really annoying issue with a bouncy tach, both at idle and at speed. It was not due to varying rpm but rather a noisy signal, which I thought was perhaps a grounding or other interference issue somewhere along the line. Peep did not have any advice other than to swap the tach feed pin from EC36 pin 4 and to EC18 pin 4. That cured it, but I still notice a slight pulse in the other gauges (factory boost and fuel) which very well could be a grounding or noise issue.
I will probably leave the VEMS harness in place including the MAT and WBO2, so swapping between factory and VEMS would then be a 30-minute process. I will attack the bellhousing ground when I install the new R and S sensor harness. And then, when I feel the need to punish myself, I can try to get this working like it should.
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hmm....really don't like hearing about issues like this. I have held back selling my last set of DME/KLR boxes just in case. On a lighter note I was able to finally figure out why my VEMS would not communicate with my laptop. Turned out to be a com port issue. Anyway I was able to FINALLY take the car out for a tuning drive and learn how the VEMS responds to live tuning. Drove around for 15-20 minutes and got the car running ~decent on light throttle. I felt like that was a success for the day and parked it. I move at a glacial pace. LOL
With trigger error rpm should not rop to 0 and that applies to fuel injector pw also. Open log file and add a pane where you choose to display some flags also (afterstart, trigger error flag etc), if you see afterstart flag right after cutout it means that you get arcing at high load and ECU resetting. With the 5k rpm trigger issue wverything works like it should also after it happens, you should not get no spark situation.
I wanted to share my latest update re VEMS on my 951. I very much appreciate all of the input and focusing on potential signal noise, I have just finished installing a Lindsey speed and reference sensor harness as mine was marginal, and also took the time to clean the bellhousing grounds. Just wish I had two sets of hands as an extra small set would be helpful at times...
So I just wrapped that up and the car runs great with the factory ecus. I still have all of the VEMS harnesses in place so I popped in the VEMS box and, nothing. As soon as I synched the laptop I realized that VEMS is in "Safe Mode Active" which I believe kills spark and fuel, which may be very safe but of course not much fun.
I have a message into Peep, but wanted to also get this out to the community here as there is a lot of knowledge and the more dialogue that is out here the better it may be for others who run across challenges.
So this may be a simple question, but how does one shut off "safe mode"? I don't have any anti-theft connected so this sounds like it should be simple.
Thanks DLS. I saw that but I have no idea what is meant when the documentation says
"from firmware version 1.1.83 (I'm running 1.2.32) the Injector and ignition outputs are disabled by default right after firmware upload, until they are enabled by either:
a special firmware-version dependent configuration word (named prohibit, 2 bytes) re-enables it
naturally, after firmware upgrade, this word will be wrong, and need to be set. VemsTune sets correct value automatically after upload of full (.vemscfg) config (to leave "safe-mode")
Sounds like I need a special configuration word, and I would try one of the above ones but I have no idea where to even input the configuration word.
DLS - I was traveling for business and just got home. I will play around a bit tomorrow to see if I can get it running well on VEMS, but I have a track day coming up and may just run the stock ECU as I'd rather be driving than working on the car
Turns out that when I did the VEMS install I also changed out the engine harness with a 89 65k mile harness I have had on the shelf for years. For whatever reason IDK the 4 pin square red plug only had the male side. So what I did was connect the VEMS tach output to the Green w/ black stripe = tachometer signal. After using the trick Tom provided here and verified the issue.
I believe my car may need an exorcist to drive out the demons. I installed a new harness for the speed and ref sensors, and cleaned the bellhousing grounds. I took it to the track on Sat and got in 75 really good miles with the stock ECUs with the car running very well. Then, halfway around the circuit, it started surging and backfiring and losing revs and power. It died just after getting it into pit lane and no spark. Towed it home (I trailered it there), checked the coil and installed new reference and speed sensors and still no spark. Guessing that the DME may be shot, but I don't see any obvious burning on the circuit boards
So I am back to sorting out this VEMS.
It is stuck in safe mode and I cannot seem to get it out. I tried a firmware update but as soon as I go into the wizard I get a Comm error and my laptop stops communicating with the VEMS. I skipped tried skipping the wizard, and it looked that I was updating the firmware, but as it ended the count down of the installation ETA (approx 10 minutes) it disconnected with another communication error, so I never got to the step where I can upload a good, saved config file.
I just got my car back from mechanic after getting head redone. The valve stem seals were gone. I also got new timing gear fitted as teeth in old gear were also badly worn. I also fitted a new ICV. I got car back and idle is oscillating at 1500 rpm. I have loaded original config file Peep supplied the unit with. I have tried adjust the idle ref curve down but it makes no difference. Vacuum lines have been checked and all look good. All I can think is it is ICV. Old one was fine but had new one sitting there, so figured no harm in getting it fitted while doing the work on car. I am thinking I should fit old ICV. What do ppl think ?
EDIT: FIXED!!!
Went over to mechanics to pick up old ICV, and while there he said he would swap them. Well he did and same issue. He clamped the Hose from ICV to intake and idle dropped. He then unclamped it and disconnected the electrical connector and no change, So he explained the ICV is basically to stop car stalling under certain conditions and one of his customers S2, they deleted it, and he got another 5kph down the straight and better fuel economy. We left it clamped and adjusted the manual idle screw till idle was good. He said see if it stalls and I drove off with clamp securely in place. It didn't even get close to stalling so I have now deleted the ICV. Car is running great but still need to do a decent autotune.
Last edited by Cyberpunky; 10-03-2018 at 05:14 AM.
09-03-2018, 06:18 AM
