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How come you have 1.2.38 firmware at all? VEMS is shipped with 1.2.32 and valid config, updating firmware is ONLY for cases when it is really needed (under strict instructions) or person is experienced enough to experiment with firmwares and features.
Unless you plan using some features from 1.2.38 (like analog input multiplexer) I strongly suggest flashing back to 1.2.32 and using your working config.
Swapped out hi Torque starter for stock unit and still same issue. Ohm out speed reference sensors and both around 924 ohms, will grab an oscilloscope to check output but I also did a trigger log of both conditions. Please see attached pictures of both trigger log png, marked good and bad. Also uploaded two videos of engine running and video on vems screen. Good condition, lambda is good, afr is good and idles a bit below 1k. Bad condition lambda is not spot on, afr is lean and idles below 900. You can clearly hear the difference in exhaust ton, even though it's straight pipe, you can hear popping in the bad video. I've got 72# delphi hi impedance injectors, saving up for deka 80s. New fuel pump filter, tank outlet filter, bosch 044 fuel pump, CEP fuel rail with automotion adj. Fuel pressure regulator ( this is probably the next step in troubleshooting, this or the fuel damper?) anyways check out the pics and videos and share your thoughts. I'm inclined to send my ecu in for repair also after burning the ignition transistors, but this issue I'm having was before I blew them. Or if someone is willing to test my ecu, I'll send it and see if issues follow. Thanks in advance.
Forgot to post these pictures. It's the VEMS ecu main board. As you can see I burned a trace when u blew the ignition transistor. I placed a jumper wire to fix it. I also notice a resistor out of place, wondering if anyone else's is like this also.
Originally Posted by shortyboy
Originally Posted by Droops83
Have you ever used a timing light to check the timing values at various RPMs and compared values after "good" and "bad" starts, and compared it to what the VEMS thinks it is? If the values are different between the two modes at the same RPM, that would confirm some sort of trigger issue, though it seems like you've tried everything related to that . . . . .
I have not tried using a timing light yet to verify timing with vems. How would I do this, have not checked timing yet on my 951.
Originally Posted by Raceboy
If there is some trigger issue (missing trigger events, noise etc) then it should throw trigger error flag with information which type of trigger error there was. And would be useful to record triggerlog (Tools -> Record triggerlog) for both good and bad starts, that would help to eliminate trigger issues and wasting time if there is no problems.
Also regarding req_fuel, it doesn't matter what it is as it is just a multiplier for VE table and you cannot compare VE table values directly anyway unless engines are identical. You can compare VE table shape but that is also affected by injector dead times etc.
Hi Peep,
see above for my post a while back regarding trigger logs. The smooth or flatter pair is a good start condition, the jagged or wavy pair is bad start. I will also report feedback after bypassing resistor on ECU36 Pin 27.
How come you have 1.2.38 firmware at all? VEMS is shipped with 1.2.32 and valid config, updating firmware is ONLY for cases when it is really needed (under strict instructions) or person is experienced enough to experiment with firmwares and features.
Unless you plan using some features from 1.2.38 (like analog input multiplexer) I strongly suggest flashing back to 1.2.32 and using your working config.
Yes you are totally right I mistakenly followed the prompting to update the firmware my mistake
I'm a total neophyte when it comes to this my thinking was that just like other electronic devices updating the firmware was a good thing.
I understand you must disable the coil and injectors when doing the firmware update is it enough just to disconnect them in the engine bay?
Bosch sensors came in today, got them at Rock Auto for $25 each! Installed, but issues still there. Is anyone here using Ice Sharks cable kit, battery, alternator, starter? How about the Nissan Quest alternator? Maybe its a combination of them aftermarket parts Ive got? Hi Torque starter, Ice Shark cable kit and Nissan Quest alternator. Here is a trigger log png and log file, you can clearly see it going lean when i give it gas, ill upload two new videos of good and bad running. Back to the drawing board. Or liquor cabinet.
OK, the one thing I notice from those videos is that the TPS % barely goes up when you open the throttle in the "bad" video----I assume that you're snapping the throttle by the same amount as in the good video? Don't you have some odd throttle body setup? Have you checked that its TPS is good, and that it correlates to the actual throttle opening?
That's all I can tell from the data presented in those short videos, everything else seems normal. If you can get the car to my shop in Santa Barbara, I could fix it
OK, the one thing I notice from those videos is that the TPS % barely goes up when you open the throttle in the "bad" video----I assume that you're snapping the throttle by the same amount as in the good video? Don't you have some odd throttle body setup? Have you checked that its TPS is good, and that it correlates to the actual throttle opening?
That's all I can tell from the data presented in those short videos, everything else seems normal. If you can get the car to my shop in Santa Barbara, I could fix it
In the bad video I'm trying to Rev it but it's so lean and alot of popping. It's a Ford TPS on a 65mm TB
In the bad video I'm trying to Rev it but it's so lean and alot of popping. It's a Ford TPS on a 65mm TB
That's what I am saying----if throttle/TPS were OK and something else was causing a lean condition (large vacuum leak and/or lack of fuel), you'd still see the TPS % go up by the normal amount as you snap the throttle. The injector pulse width, MAP, etc look similar between the two videos, but TPS gets up to ~25% in the "good" video, and only about 5-6% in the "bad video."
I could be wrong, but this would be pretty easy to check.
That's what I am saying----if throttle/TPS were OK and something else was causing a lean condition (large vacuum leak and/or lack of fuel), you'd still see the TPS % go up by the normal amount as you snap the throttle. The injector pulse width, MAP, etc look similar between the two videos, but TPS gets up to ~25% in the "good" video, and only about 5-6% in the "bad video."
I could be wrong, but this would be pretty easy to check.
I was revving the throttle the same (at least I think I am) , in both videos. I highly doubt it would be a vac leak or lack of fuel, because in 3 to 5 restarts, I would get a good start condition again
. Seems almost like a huge voltage drop, causing settings to change. If you've been following what's been replaced so far. Tank outlet fuel filter, bosch 044 fuel pump, outlet filter and lines, aeromotive fuel pressure regulator, siemens deka injectors. Fae, facet, bosch speed/reference sensors. Ignition switch. If my voltage drop theory is right, then it would either be my battery cables or Nissan quest alternator. Will swap in my stock alternator and wire vems power directly to battery with a 3am fuse. But I'm still stumped at what would cause a good start condition every few starts. I really appreciate the brain storming
. Will test your theory once weather let's up. 🤙🏽
I was revving the throttle the same, in both videos. I highly doubt it would be a vac leak or lack of fuel, because in 3 to 5 restarts, I would get a good start condition again
. Seems almost like a huge voltage drop, causing settings to change. If you've been following what's been replaced so far. Tank outlet fuel filter, bosch 044 fuel pump, outlet filter and lines, aeromotive fuel pressure regulator, siemens deka injectors. Fae, facet, bosch speed/reference sensors. Ignition switch. If my voltage drop theory is right, then it would either be my battery cables or Nissan quest alternator. But I'm still stumped at what would cause a good start condition every few starts. I really appreciate the brain storming
. Will test your theory once weather let's up. 🤙🏽
I don't think you are understanding the point of my last couple of posts: the outlier is the TPS% data. The point is, your TPS reading should be the same if you are operating the throttle the same level, regardless of whatever else is going on with the engine. For example, if your actual problem was a fuel-related issue, the TPS readings would be the same in both videos, again assuming that you are snapping the throttle at approximately the same rate.
As for your voltage drop theory, there still could be a voltage drop somewhere (5V reference circuit, etc), but the voltage reading at the VEMS display is virtually the same in both videos, which means that the ECU itself is getting the required voltage.
Because of the wonky TPS readings and the fact that you have changed the throttle setup, eliminated the ICV, etc, I would at least eliminate that as a possibility. I am not 100% convinced that this is the problem, but that is the only obvious anomaly in the data that I can see in the short videos provided.
I don't think you are understanding the point of my last couple of posts: the outlier is the TPS% data. The point is, your TPS reading should be the same if you are operating the throttle the same level, regardless of whatever else is going on with the engine. For example, if your actual problem was a fuel-related issue, the TPS readings would be the same in both videos, again assuming that you are snapping the throttle at approximately the same rate.
As for your voltage drop theory, there still could be a voltage drop somewhere (5V reference circuit, etc), but the voltage reading at the VEMS display is virtually the same in both videos, which means that the ECU itself is getting the required voltage.
Because of the wonky TPS readings and the fact that you have changed the throttle setup, eliminated the ICV, etc, I would at least eliminate that as a possibility. I am not 100% convinced that this is the problem, but that is the only obvious anomaly in the data that I can see in the short videos provided.
Before starting the car, I verified vems is seeing tps correctly by tapping the throttle. Then after starting it, on the bad start, it won't read it correctly, idk if it's cause it's seeing rpm is alot lower than it is but it's obvious that when this condition happens it has to do with speed. Reference sensors no telling vems the proper rotation speed. There is also no trigger errors when the bad condition happens.
Originally Posted by H.F.B.
Your MAP reading (video bad running cond.) seems a bit strange to me. TPS 3%, RPM 821, MAP 37. I never get values like this.
Something not communicating right between speed sensors and vems. But every few starts, it gets the correct info. I'm stumped. A local guy who. Has vems on his supercharged n/a has agreed to try out my ecu with his config. We verified our injector and ignition pinouts are the same. As far as alternator theory goes, im getting 14v+ at the battery and 12.6v when car is off. Starter sounds the same every time I crank her over. Just when it catches is different. When I see the tach start below 1100 I know it will be a bad start. If it goes up to 1200rpm, it's always a good start. Injectors flooding cylinder causing slower rotation? I'll grab a tachometer at work to verify speed, just need to find an adjustable timing light to verify timing. And instructions on how to perform it.
I also assume that this issue the 3 of us are having is some what related. I think it's something we have in common causing this issue. Which is why I brought up Nissan quest alternator and hi Torque starter.
Your speed sensors are totally fine, trigger signals are clean as a whistle.
But TPS should read identical in all conditions, regardless of rpm etc. It HAS TO reflect actual throttle movement.
In the bad running video it is clearly running too lean, you can hear pops from the intake and lambda reads also very lean.
Where have you taken the vacuum signal? It has to be taken from intake plenum, as close as possible. On factory cars KLR boost line has correct signal and no noise but for example factory S2 models have FPR line tapped together with HVAC vacuum and they can occasionally run way rich even in stock form...
Your speed sensors are totally fine, trigger signals are clean as a whistle.
But TPS should read identical in all conditions, regardless of rpm etc. It HAS TO reflect actual throttle movement.
In the bad running video it is clearly running too lean, you can hear pops from the intake and lambda reads also very lean.
Where have you taken the vacuum signal? It has to be taken from intake plenum, as close as possible. On factory cars KLR boost line has correct signal and no noise but for example factory S2 models have FPR line tapped together with HVAC vacuum and they can occasionally run way rich even in stock form...
TPS is a new Ford tps on a 65mm throttle body. I calibrated it in the tps calibration screen. When I get bad start condition, it does not respond well, like lag when I press the gas and when it actually revs. On good starts it works perfectly.
Vacuum line has its own port off the intake manifold straight to vems ecu with nothing tied into it.
02-14-2019, 10:07 AM
