MembersPage/EricN/Trigger (2006-03-16 04:43:08)

Trigger related page for MembersPage/EricN

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.

inputtrigger.jpg


My plan is to run as a 12 cyl (engine is a 6) pretending to fire wasted spark so I can use the COP coils. I thought I read somewhere about setting the number of cycles that will trigger a reset (not sure if I worded it right but meant that engine sees the missing tooth 2 times then it starts over) Not too sure if setting that to 1 cycle would work somehow, need to try and find it again.


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. 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 capaciter or some noise filter of some sort, could that be what I need, and where did I see that?? My scope is at work so I couldn't check with that to confirm but it sure "feels" like that is the problem.

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

The 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

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. Unfortunately I ran with the fuel valve shut partially off and starved the fuel pump, murdered it. I am now second guessing my problems as being fuel pressure related, not the trigger. Where on the lcd does it show the trigger error counts? I have looked at page 1 and 2 and I am not sure what I am looking for. I definately dont see the word "trigger errors".


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.

The truck is a 6 cyl. I am firing cop coils and using a distributer mounted 24-1 trigger wheel. I have a trigger event every 60 degrees. If I understand right, with #1 cyl at tdc, my vr sensor needs to be placed less than 60 degrees away from my TRIGGER tooth (I used first tooth after missing). Is this correct?

I tried to use 53 degrees 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.