MiataManiac

Hey guys,

just registered a few days ago and here comes my first problem - should I re-consider signing up at this board ;-)

I have an issue with my 1992 FM2 with a Link ECU. Sometimes, my Intake Air Temperature reading on the link keypad showes 100 C. The ECU won't let the engine go into bosst as a precaution, of course. Two days ago, I thought, I found the reason in a bad sensor ground on the IAT sensor. So I replaced the ground wire and terminal, cleaned the contact spots and it worked for one single day. Again, I have the same problem. Sometimes everything is good when I start the engine. Later, the IAT reading would go to 100 C again when I hit more then 4k rpm for example. And sometimes the reading shows 100 C already when I start up the engine. I have already been trying different spots to ground the sensor cable but nothing would improve the situation. So much about explaining my situation - I hope my english is good enough to explain to you what's going on ;-)

So my questions would be

1. Could this be a bad sensor? B/C sometimes it reads right and sometimes not - maybe vibration issue?

2. If it's not the sensor, what could I do? Run a new wire from the sensor to the ECU, I guess? Or is the grounding point on the intake manifold just a bad idea? I don't think so, since it has been working there for quite a while.

Thanks for your advice!

Take care
Axel

Juffa

G'day from Downunder Axel,

I had a similar problem with my FM/Link ECU. It was a bad earth. I just had a read of the ECU tuning manual, and as you have already said a badconnection will casue a reading off 100c and reduce boost. If it is not the earth connection then check that you have a good connection at the ECU end. Also check that the solders at the IAT sensor are not cracked or broken.

Worst case is that you may need a new IAT sensor, not sure if FM still sell them or if there is another type you can use with the FM/Link ECU.

Good Luck.

J