Any developments? :cool:
Nothing yet. Hopefully this weekend. Just got my coils and ecu but want to try some other suggestions first.
Back too the drawing board I obviously missed something. Not likely ecu Definately not the coil Checked coils and wires for resistance to ground and got 0 ohms
Michell said this some time ago and i think i jumped right over to testing the coils with the oscilloscope. And never tested cam phase signal What should the came phase sensor test oit at, and what settings on the scope Thanks
Mitchell said this again and i missed it. “ scope out the phase sensor signal at ecu” Everyone likely thought i did this. Will do it tonight and report back
Grant, The theory of operations for the cam sensor is below, and also the picture of the signal is below. You should look for a 12V signal, with a negative duty cycle of about 10%. The oscilloscope should be adjusted to 5V per division and a few milliseconds per division Image Unavailable, Please Login Image Unavailable, Please Login
I would think if there was a problem with the cam signal, the engine would not even be able to start. But it wouldn't hurt to remove it from the list. You mentioned in post 253 that its not likely the ecu. How did you arrive at this conclusion?
I think Grant may have been working on the assumption that two components would have to fail in the ECU to cause the both coils in the coilpack to fail. However, the power transistors in the ECU may have a single triggering component. Can the spark timing be varied on pairs of cylinders (and what would be the point)? It may also be a good idea if all the circuits are checked properly prior to the installation of the new ECU in case something blew up the old one.
Tried the new ecu and it mad no difference. Tried both new coils and no difference. As others have said before that it was not likely ecu i believe they are correct because replacements made no difference. Normally I would have check other components first but being my car was an f1 i have wanted a spare ecu for a while so i figured i might as well buy one now. Too late to not plug in the new ecu but i am quite sure nothing blew up the old one or the new one.
Image Unavailable, Please Login I found this in the wsm but not really sure of the scope settings Any help would be appreciated so i can check the cam phase signal at the ecu.
Have you already hooked up the oscilloscope to the pink wire on pin 21 and you're not getting a clear signal? The workshop graph seems to be suggesting 5 volts per division (which I find odd). The input voltage to the cam sensor is 12 volts, so I would expect no more than that as an output. The Ferrari graph is showing 17.5 volts! I would start with 5 volts/per division and go down to 2 or 1 for a better resolution. The period of the waveform will be related to cam rpms. Normally you should see at least one dip in the waveform on the screen. If you start at the 1 millisecond* (mS) increment (division) and progressively lengthen the time base, you should start to pick up multiple spikes/dips. Unfortunately, as you can't get your engine started, the cam speed will be related to starter motor speed (and that will depend on how healthy your battery is). The rpms may be erratic, so your waveforms may jump around a lot. *or maybe smaller (It depends on duty cycle and rpm). It also depends on what you are trying to see: The shape of the wave as it drops... or the time between two drops.
Grant, did you check the centre pin voltage of the coilpack with the engine cranking (or semi-running) with the oscilloscope? (as suggested earlier). We seem to be running out of ideas. Maybe the wiring is breaking down under load. I'll try to determine exactly which plug on the passenger footwell relay panel powers the RH and LH coil packs, then see what is in the RH and LH coil pack wire harness branches. The fuel tank vent solenoid is on one of those branches. Perhaps you could disconnect the plug on the vent solenoid to see if there is an improvement? Also on one of the coil power harness branches is a yellow wire which goes to the alternator. How easy is it check the wiring near the alternator? The yellow wire goes to the alternator via the 12 pin waterproof connector near the left rear shock strut (under the side cover). If I understand correctly, the yellow wire is a sense wire which boosts alternator power when the electrical system is under load.
Remember i jumpered 12 volts to the coil pack so it had lots of power and nothing changed I have the car on a battery maintaner each day after testing somlots of power on first start so likely not much to do with the alternator i dont think I will check that plug and also this reminds me i did partial damage a plug over in that area during the engine out so i will post a pic of that plug and maybe someone can see if it might have something to do with it.
No i have not hooked up pin 21 yet Mitchell politely asked me to do that 2 times. Him and Fbb have met me so they know i am kinda slow but unfortunately i missed it due to focussing on the coil packs once i got the oscilloscope. Will check to night. But will also take cover off an look at the piece that plugs on the cam, maybe a pin is broke. Will check signal first thought in case its good.
Please disregard the fuel tank vent solenoid theory. I pulled my car to pieces (the things we do for our fellow F-Chatters ) including removing some of the plugs from the back of the passenger footwell relay panel. I found that the fuel tank vent solenoid is actually powered by pin 7 on plug "I" on the relay panel (which is unrelated to coil pack power). I also found that I had reversed the coilpack power wires (at the relay panel) in my diagram. Anyway, since these wires are joined internally in the relay panel, they still have the same non-fused ignition power source. Here's an updated diagram: Fig11a_1997_5.2_Injection_System_Ignition version 16 My previous diagram wouldn't have affected your wiring tests (unless you started pulling plugs off the relay panel). I can't easily access my alternator, so I can't check which pin/plug on the relay panel is hooked up to the alternator. The point I was trying to make about the yellow wire going to the alternator is that it probably won't affect the normal operation of the alternator, but it tells the alternator to boost its output when the electrical system is under high load. However, if this yellow wire is perhaps shorting to earth (when the engine is vibrating), it might be dragging down the power supply to the ignition coils. No fuses will blow as a result of this because these coil wires are not fused, but it may draw power away from the coil pack/s.
Right Ian but if this was the case would applying power to the power pin on the coil would it not give more than enough power to overcome that?
Image Unavailable, Please Login I believe this is the plug I kind of damaged buut i thought i fixed everything on it Its the plug by bracket 43 and mounts to the car frame
Perhaps, but electricity still wants to take the path of least resistance. A short circuit to ground is "least resistance". A partial short circuit in house wiring may dim the lights even though you have the national electricity grid providing power
I'm not sure what that plug is. It may be the fuel tank vent valve plug, but it's oriented differently to mine. Mine is horizontal. I'll have a look at my car to see if I can follow the harnesss.
That is an important plug. Please go back and make sure all the pins are in tact and all both male and female connectors are good.
Ah, that's probably plug 41019. That has the following wires: PIN/Function 1 starter solenoid power from ignition key 2 speedo sensor power 3 water temperature sensor signal for gauge 4 alternator power sense wire (for sensing electrical system power load) 5 speedo sensor signal 6 oil pressure "low" light circuit 7 aircon compressor control 8 oil pressure sensor signal 9 small red wire going from alternator to battery (function unknown) 10 water temperature "high" light signal 11 something else related to the alternator 12 alternate power path for starter solenoid power (from ignition key) You've just given me a good idea.... be right back...
OK, I just confirmed that passenger footwell relay panel plug "I" (pin 9) supplies power to both the right coil pack and also to the alternator sense wire (via plug 41019 (pin 4)). Whether it is relevant to the fault, I don't know, but as John says, it's an important plug. Here's version 17 of my wiring diagram. I had to add some splices in the right coil pack wiring. Refresh browser as required to view the latest version: Fig11a_1997_5.2_Injection_System_Ignition Version 17 See the left hand side of the diagram for socket/pin configuration of the plug.
I believe we are talking about this plug (Plug 41019) Image Unavailable, Please Login The top half (female/sockets) goes to the relay panel. The bottom half (pins) goes to the sensors, alternator, aircon compressor, etc.
