Trigger related page for MembersPage/EricN
Board is a v3.2 serial number=110
STARTING OVER
Take photo of the current state (both sides). Try to use natural orientation and good focus.
- vr+ wire goes right to the top right header pin and bypasses the EC 36 connector (overcautious)
- Soldered jumper on the bottom of the board (good; but take photo so we can verify)
- I removed the R30 pullup resistor (yes, it was necessary!)
- The black wire (now removed) was connecting LM1815pin5 to +5V (LM1815pin8) to eliminate the adaptive hysteresis (and set high threshold).
Now that I have the RPM constant set right, the thing idles excellent (maybe ign idle control is working) but the trigger drops out way more than before (I can barely get it to start).
The above suggests that you select the adaptive hysteresis (LM1815pin5 left open), but all connection to C38 is broken: the resistor in series with C38 is not soldered properly (or at all)'''. If you need the modification for the irregular missing-tooth shape, remove the ugly throughole resistor and follow the updated instructions on
- I noticed every now and then the lcd freezes or gets garbled when my drop out happens
- Also had the keyboard stop working when I was trying to drive it, not sure why, it works fine now on the bench.
The above suggests that the LCD supply shorts to GND due to shaking. Maybe the backlight resistor ? Try without PS2 and LCD (only MegaTune) to find out if this is the problem.
BACK TO FRUSTRATED
Replaced all my ground cables, added some new ones. The best I can manage is about 1100rpm safely, much lower than that and it will for sure start acting up. Here is a [pic of my board].
![[pic of my board]](http://www.vems.hu/files/EricN/lm1815area.jpg){kind=link}
- solder the trigger (under the board) instead of a movable jumper
- apparently you use a v3.2 and haven't removed the pullup resistor R30 from the VR input. See "setting up VR on v3.2" section on GenBoard/Manual/InputTriggerHardWare
- what is the black wire doing near LM1815pin7? What does it connect ot? Is it a GND, or LM1815pin5 for changing adaptive hysteresis, or something else?
Another issue that I think is related, if I hit any part of the engine with a tool I can make the ecu trigger. The closer I get to the distributer, the less force I need to do it. I need just to lightly touch the distributer with a tool and it fires away.
Incorrect RPM reading is caused by RPM constant misconfiguration: you used 3000 (the 4cyl value) instead of 2000 (the value for 6 cyl). See MembersPage/EricN/Config
Also drove the truck today just for the heck of it. The problem actually happens at almost any rpm, it just isnt as noticeable when you are free revving the motor, add a load though, all hell breaks loose.
MAYBE SOME HOPE!!!
Got bored/mad and went and bought a few feet of new 00 guage cable. I replaced 1 chassis ground wire untill it started raining BUT I did start the truck after. The trigger is almost perfect. Before, it would cut out at anything below 2800 rpm. Now, I can get it down to about 1000-1100 before it starts cutting out.
I have 3 more major cables I am just going to replace and ditch the battery cut out switch and try from there. I may adjust the vr sensor closer to the trigger wheel too.
Interesting thing now is, I can bang on the side of the distributer with the truck not running and I dont get any triggers, but I always get at least 1 error on the lcd when cranking and when I am trying to run the truck at really low rpm (I mean idle) I get an error count or 2 when the ecu cuts out. I rarely got errors before, and never while running, even when it would die.
crank_minper=0D will work for a 6cyl. It mean that any measured time for 120 degrees period less than 13*16 usec is considered garbage.
The minimum time it takes the crank to do 120 degrees. The minimum time happens at maximum RPM, (eg. 7000 RPM)\n
primary_trigger=01 secondary_trigger=02 tooth_wheel=17 trigger_tooth=01 another_trigger_tooth=04 crank_minper=0D tooth_wheel_twidth1=05 tooth_wheel_twidth2=19 cam_sync_r_edge_phase=8D cam_sync_f_edge_phase=21 reset_engphase_after=D8 ign_tdcdelay=6A ign_dwell14=2F ign_dwell6=B9 ign_crank_advance=14 ign_out=70 ignchmax=05
The full config is MembersPage/EricN/Config
And just to re-ask a question
- I was under the impression the mda.. command ADDED that much advance.
- It's not the case. mda28 forces the advance to be only 40 * 0.25 (=10)degrees. mda3c forces 60*0.25=15 degrees advance?
I GIVE UP
The VR trigger is killing me, I have tried many things, even shorted pin 5 and 8 on the LM1815. It definitely worked alot better, but I still get the same dropouts.
- I read and understood about the shape of the signal at the missing tooth having the amplitude too high, so I welded and ground until the scope showed a nice, even amplitude. I thought shorting those 2 pins would have solved it. The scope shows the trigger as an hourglass shape and when I freeze frame and measure, the peaks change from 7.5 volts at the shortest peak and 11.5 at the tallest. It is going in the garbage.
- the minimum amplitude (near normal teeth) compared to the maximum amplitude (around the missing tooth) is 65% (= 7.5 / 11.5)
- Stuck the distributer in the lathe, cut out all the runout. I now go from a highest peak of 7.4v to a lowest peak of 6.9v and it is not around the missing tooth. Even now, it still cuts out.
- Board is a v3.2. I tried the mod by cutting the trace off of pin 7 and putting a 100k resistor in its place. It didnt help. I also shorted pin 5 to pin 8. Would that not make the pin 7 mod completely unimportant?
NEW PLAN
I have a distributer with an optical sensor (eventually was going to end up in the truck anyways). Supply voltage to the sensor is 7 volts from the module. Connect the module and it is 1.24v. The output is 1.24v (while connected) when the window is blocked and 0 when it is not.
- Do I connect this just as if it was a Hall sensor?
- yes. the HALL input is designed for 0/5V signal, which is better than the 0 / 1.24V. Some hack might be needed to push down input threshold (offset with 2 resistors: onboard change or outside). Since - if going this way - you must change onboard jumper blobs anyway, don't assemble until you tested the input threshold to be around midway, that is 0.62V
- I realize I need to steal 7 volts from somewhere but seem to recall it is available on the board.
- not really. The max232's +8V (and -8V) are for 1..10mA or so, not for a module like this
- we use 3 diodes under the 78L05 (regulator) GND to make 7 volts. Optionally the regulator GND point can be connected to the midpoint of a 5k/2k (or so) resistor divider with a 5V regulator. See adjustable regulator's (LM317 ?) datasheet for hints. Don't forget 100..220nF caps from input and output.
BELOW THIS IS ALL GARBAGE, JUST WANT TO SAVE SOME FOR REFERENCE NEXT TIME I GET THE IDEA TO TRY IT
Started over with input trigger ideas. Took a VR sensor and 24 tooth trigger wheel out of a Honda Civic distributer. Ground off 1 tooth, pressed it on to a gutted Unimog distributer (took the whole advance mechanism out). Welded a plate inside, mounted the VR sensor on the plate. Now I have a 24-1 trigger wheel driven by the cam.
If I see right, this wheel is very prone to output bad signal at the missing tooth. If you can, record it with a soundcard. To be safe, divide by 50 (or so) using a 100k and a 2k (or so around) resistor. It might output just higher amplitude signal at the missing tooth, or maybe it has a ghost pulse too.
truck is a 6 cyl. I am firing cop coils and using a distributer mounted 24-1 trigger wheel
Distributor mounted ? Are you sure ? Many things below assumed (before I started to correct them) your wheel is crank mounted.
With distributor mounted 24-1 you can do full sequential, and fire the COP coils just once per camrot.
QUESTION 1
After a major ordeal with some dead spark plugs and bad grounds, I got the truck running enough. Only problem is every now and then I get a completely dead half second and then it comes back to life. When cranking, I notice that every now and then the rpm dies off to zero for the same half second then comes back. Likely trigger signal shape problem.
Other than that, the rpm stays pretty constant other than the 3000rpm blip when I hit the start button. If I touch the body of the distributer with a wrench (vr sensor in distributer is my primary input trigger) while the key is on but car is not running, it triggers the ecu and injectors and coils fire a quick shot, enough for big flames out the throttle body.
- I remember reading somewhere about installing a capacitor or some noise filter of some sort...
- The LM1815 chip that converts VR signals to a nice signal for the controller is autosensing trigger signal levels, and if you receive a large peak, it takes a while for this peak detector circuit to come down to your normal levels. This probably explains your behaviour. //Emil Larsson
- If you have a v3.2 or older, a 150k (or 100..220k) resistor in series with C38 might help. See InputTrigger/RunOut . This should be able to pushe down adaptive hysteresis threshold under 65%. TRIED IT, DIDNT WORK, HELPED A LITTLE
- Can you take a photo of the board LM1815 area ?
- Did the pics, batteries died, will upload when they charge.
- make sure the onboard arch between GND and GND5 is cut done
- draw your GND and GND5 connections, with realistic line-lengths and take note of wire-thickness.
- Dont have a nice program to draw it in but I measured it out. The gnd5, I have 4 wires, 26" long, 18guage. It goes to a lug with the 00 guage ground cable that leads to the battery. The other ground is 32" long, 16 guage, bolts to the intake manifold. The sensors meet it there. They are 18 guage and the longest one is 6 inches. The vr sensor is the longest at 38". The ground wire goes right inside the ecu and is soldered to the ground on the board above the input trigger jumpers. The only things loading up gnd5 are 2 injectors, the fuel pump relay and the wb heater.
A:
You most likely have noise problems with your trigger, make sure the distributor is properly grounded and the sensor too if it's supposed to, where do have you grounded the VR Sensor circuit? One pin goes to trigg1 input, other to ground, Near EC36 pin26 and not in a GND5 path.
MORE:
I tried to run a ground wire from the distributer housing to various parts of the block and chasis and eventually tried to the battery, I can still lightly tap the distributer housing and trigger the ecu to fire the some fuel and spark. Is it possible that this is normal? I ran the ground wire for the VR sensor right inside to the ecu so I dont think that one is bad.
The LCD mlp01 page show the trigger error counts as W..
- No errors show up on lcd. Once in a while I might get 1 when I first push the key to start the truck but not usually.
Here it is\n
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
Put the carb back on but left the coils and input trigger in place and just ran the spark on the ecu. The same problem still occurs so I am convinced it is a trigger problem. It happens maybe every 15 seconds or so. Gives me a good blast out the intake, caught my oil bath air filter on fire.
QUESTION 2
I thought I had the input trigger lined up but I had to move the distributer to get everything to fire properly. Just to confirm, this is what I did.
I tried to use and put the trigger area in between 2 teeth but it needed to be played with to start the truck, altough that may be related to question #1 with the trigger dropping out. With the engine running, I set the advance tables to zero (not aware of mda.. command? mda28 will force 10 crankdegrees advance, that is decimal 40 * 0.25 degrees; mda01 forces 0.25 degrees advance, mda00 restores normal advance calculation; see refcard on GenBoard/MenuSystem) and pointed my timing light at the crank, adjusted the distributer till #1 was firing dead on tdc.