Tacho not working

[Juffa]

So, last Friday the fuel pump and the tacho stopped working. I had to jumper the FP to GND in the diagnostics connecter under the hood to get the fuel pump to work. I had dríven her the day before in 40+ degree heat without any issues.

I know that the fuel pump issue can be caused by the Circuit Open Relay, but that should not cause the tacho to fail. Later on Friday I removed the jumper from the diagnostics connecter and she started ok, but the tacho is still not working.

Last time something like this happend I had to replace the ignighter module. In that particular case the car was missing badly as it was only running of 2 cylinders.

I have cleaned the grounding point for the group of ground wire under the windscreen washer bottle and made sure the ground lead on thes battery is tight.

Any other suggestions?

[glen73]

Did you sort it, i dont think anyone knows otherwise someone would have a suggestion. I drove mine on that super hot day aswell, can definatley see the difference between hot days and nice cold days with the turbo.

[Juffa]

No, still not sorted. So far this is the only real issue......but it could be a sign of a bigger issue waiting to bite me. I plan on uncovering the ECU in the next couple of days and re-seating the wiring harness connections. That has worked on similar issues in the past.

J

[JBT]

As best as I can figure, tacho power comes from the ignitor and the \"meter\" fuse.

[SuperMazdaKart]

good ol mazda manual to help out. though, you pretty much know what to do

[Juffa]

Well I fixed the problem today. I bought a 2nd hand ignitor of 'wrecking' Jake and installed it. Everything back to normal...

J

[ampz]

Aren't you running a 'Link'?
What are your dwell times?
Maybe the Link is lunching your ignitor? Is it hot to the touch after a drive?

Maybe the hot day was enough to push it over the edge?

[Juffa]

Aren't you running a 'Link'?
What are your dwell times?
Maybe the Link is lunching your ignitor? Is it hot to the touch after a drive?

Maybe the hot day was enough to push it over the edge?

Yes I am running a FM Link ECU.

Not sure about the dwell times, or the heat.

This is the 2nd time this has happened to me. The cause seems to be the same in that I was having earthing issues with the ECU. In order to resolve these I needed to unplug the wiring loom from the ECU, fix the earthing issue and then plug the ECU wiring loom back in. This meant that I needed to disconnect the negative feed from the battery.

Next time I play around with the ECU I will disconnect the ignitor first.

J