Trigger related page for MembersPage/EricN
Board is a v3.2 serial number=110
Jan 06
Completely dead, gnd was broken, may have been my problem all along??? put ECU on my test bench, everything works fine, BUT no rpm reading, ign and inj channels all grounded all the time, fuel pump channel (and all the others) dead, wont respond to mdh command.
RUNS AGAIN, NO DIFFERENT, WORKING ON MORE PICS
- THE ETERNAL QUEST CONTINUES
- Can I just use 2 ceramic .1uF through hole caps in parallel for now until I can find the remaining parts or is there a better option.
- of course. Even just one 100nF should work OK.
- The only 0805 size caps I have left are 2 in a clear plastic holder with 2 positions (no missing), according to GenBoard/VerThree/RescueKit they must be "2*2.2u 0805 16V trans (tall)" which is a bit high: would work normally, but after a sudden RPM-drop, regaining RPM could need up to about 2.2uF * 1MOhm = 2.2sec after the _start_ of the RPM drop.
- if your DVM measures capacitance, you can measure it
- if you need the 220nF, that's the paper carrier with 8 (longest of all!) pieces
- we can send you rescuekit for free (to Canada, so I asked Jason to send from USA East Coast)
STARTING OVER
Take photo of the current state (both sides). Try to use natural orientation and good focus.
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).
- 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.
- Suspect this was caused by gnd wire coming apart at EC36 pin26
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}
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\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
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 a little 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?
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
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 split 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
- 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 VR 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.
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.
- 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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With the engine running, 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.