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Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 1:20 pm
by Steve M
Distributor sensor shield
Distributor sensor shield
Black is shield ground line
Black is shield ground line
Where should I ground the shield?
a. Distributor body
b. HEI module mounting screw (grounds to timing case)
c. Somewhere far, far away, engine, chassis or battery.

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 2:01 pm
by festy
Is that proper shielded twin conductor cable, or was that a DIY job?

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 2:05 pm
by Steve M
DIY job.
Sensor wire pair twisted with uninsulated copper cores. Heatshrink over the top.
Next mini project will be to do something similar with an ABS sensor.

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 2:19 pm
by delcowizzid
Do you have a normal bakelite rotor you can try in place of the see through one

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 2:22 pm
by festy
I'm not sure that will be doing much, the gaps between each turn would need to be just about zero. Jaycar sell a couple of different shielded audio cables by the metre - I think this is one of the types I've used with reluctor sensors in the past with great results.

I don't suppose you happen to have access to an oscilloscope?

Have you logged it cranking over with the coil disconnected? Either disconnect your injectors or pull the fuel pump fuse beforehand to stop flooding the cylinders. That log will help narrow down the source of the issue.

If the log still shows crazy, you could then try logging it with the reluctor unplugged too - if you get *any* RPM recorded in the log, then that would hint that there could be EMI entering the wiring harness somewhere between the ignition module and ECU, not between the distributor and ignition module...

Don't keep changing everything around or you'll be trying to hit a moving target.

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 2:59 pm
by Steve M
I do have a normal rotor, which had a smaller tip on it, more like the width of the camira one. I was using that when the problems started. Changing the rotor hasn't made any difference.

I picked up some shielded microphone cable the other day but wasn't too keen to cut my reluctor wires.
How close to the sensor did you start your shielded cable?
Where did you ground the shielding?

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 3:21 pm
by kojab
Steve M wrote:Hi,

Clipped

I have been having trouble getting my engine to start,
While running, there was a large amount of raw fuel coming from the exhaust (white cloud, I don't think it was condensation. It looked more like an old diesel on a cold start)
- coil spark was sometimes strong individual pulses when battery fully charged, sometimes continuous sparking on the 3rd or fourth attempt to start.

Clipped

Replaced ignition module (2nd hand spare)


Cheers, Steve
Hi Steve.

A few things I would do.

You say above "there was a large amount of raw fuel coming from the exhaust (white cloud, I don't think it was condensation. It looked more like an old diesel on a cold start)"

When spark plugs get that wet it unlikely to get the engine running again. Even cleaning the plugs won't help. Today's fuel can do strange things to sparkplugs. Replace them with new ones.

Make sure your ignition module is earthed. Check the two screws on module are earthed. Make sure the polarity of the two wires to the distributor are correct.

Good luck

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 4:00 pm
by Charlescrown
Yea I had a problem with the engine just cutting out and it turned out I had to use a shielded wire from the dissy trigger to the Camira module. It fixed my problem but you say your car was running fine before it sat for a while.

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 4:35 pm
by Steve M
Festy, I did a few test cranks with different things disconnected. Here are the results.

No reluctor, no injectors = no RPM signal

Distributor Reluctor but no Injectors = same RPM signal problems as before

Coil disconnected (grey and black plugs) = no RPM signal (as expected)

Fuel pump fuse & relay removed. = same RPM signal problems

The ignition relay gets quite warm, is this normal?


Charlescrown - where did you start and finish the shielded wire. Also, where did you ground the shield?

Re: Toyota 18R-G (808, NVRAM, USB) - died, help please

Posted: Fri Apr 24, 2020 5:10 pm
by delcowizzid
You would of lost power to the ignition module unplugging the coil if its wired as stock join the 2 plugs that goto the + on the coil and crank it