Hi all - have an issue that I've not been able to solve. It is either something major or something stupid. Either way Paul and I need help.

Over the years we have been experiencing ECU failures - we have blown up 4 Power FCs in 4 years. We always assumed there was something wrong with our wiring harness so we decided to change from a V1-2 harness to a V3-4 harness and buy a ViPEC.

A couple of weeks later and we have pulled out the old wiring harness and fitted the new harness and now the car does't run on four cylinders. The front cylinders (1 & 2 on a wasted spark set up) work (the extractors on those cylinders are hot) while the rear cylinders (3 & 4) do not seem to be working but the car idles worse if you disconnect the coils on cylinders 3 & 4. It seems like they are possibly sparking at the wrong time?

The tacho reads extremely high. This is on both the dash and the ECU readouts. The car sounds like it is doing 1k RPM and it reads about 3-4k RPM. This is on both the older and newer cam and crank angle pulleys.

What we have tried:

• Changed the cam position sensor and pulley to the later model triggers - 2 triggers instead of 8 point triggers)
• Changed the crank pulley (to a later model pulley to match the 2 trigger)
• Changed back to standard injectors and 98 octane fuel (just in case we had blocked injectors - annoying feature of E85 and petrol is easier to start the car cold)
• Tested the ECU in Kat's car and it ran fine.
• Switched the dip switches in the ECU - changes the polarity of the cam and crank pickups
• Tested the coil on plugs and changed the spark plugs many times
• Tested all the wires coming out of the ECU all the way to the injectors and spark plugs
• Bypassed the harness wiring from the cam angle sensor to the ECU and hard wired another wire in just in case there was an issue in the wiring harness
• Double checked the coil on plug conversion - 1&2 are wired together and 3&4 are wired together and igniter has been removed as per the instructions.

Anyone else have any ideas with what we can try?

List of ideas going forward

• Keep at it and find out what is killing the car
• Give up and go Hyundai racing
• Go back to V1-2 harness and get ViPEC converted to fit V1-2 plugs (~$200)
• Buy a v44 or V88 ViPEC or MOTEC and Dash and get custom wiring harnesses (~4k?)
• Buy an Evo

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Geoff

APCV-R
AutoPro Canning Vale Racing

Geoff,

Plug in the laptop, connect to the ECU & turn the car over. There are trigger counts & trigger error counts, listed at the bottom middle of the screen in the live display.

Start the car & see if your triggers line up correctly or if you are getting error counts. I'm pretty sure trigger #1 is the crank & trigger #2 is cam

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Cheers,

Simon.

Make sure the cam angle sensor is picking up all 5 pick ups on the cam wheel, or the opposite, it's picking up more than it should.

So we figured it out - Thanks Simon!

Turns out it was the polarity on the crank angle pickup. Swapped the wires around and it worked perfectly.

Time to switch it back to E85 and tune the f**ker.

I didn't get any errors on the ecu when I plugged in my laptop but as soon as Simon plugged his laptop in we got some different errors and figured it out.

__________________
Geoff

APCV-R
AutoPro Canning Vale Racing

Simons my hero

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Fuck your signature

what was the polarity on the pick up as im trying to wire in a haltech and im scratching my head a little mines a 1998 gc8 if that makes any difference

You need to wire the reluctor sensor correctly (ie. positive is the signal wire and the negative goes to ground). The engine will run but as the revs increase you will run into problems. You need an oscilloscope to see the wave form to tell if its wired properly or alternatively perform this test:

Ref: Official Haltech Forums • View topic - Wiring stock reluctor crank and hall-effect home sensors

To check the polarity, remove the reluctor sensor and connect a mulitmeter to it on DC volts. Bring a piece of metal(iron) close to it quickly, and see if the voltage rises momentarily. If it does, then the positive lead from the multimeter is going to the positive wire/terminal on the sensor and that goes to the signal, the other is the negative and goes to ground. It will also read a negative voltage when quickly moving the metal away. If the opposite happens, switch wires around.

You maybe able to make your own osciloscope using an old laptop:
DIY: Turn your GNU/Linux computer into a free oscilloscope | Yann "Bug" Dubois