I just put in a new tach for my 88 2.5l and it still doesnt work. I need help the oil pressure gauge works fine like it did before. All the tach does is sit at 500rpm. Please help I'm getting sick of having no tach.

There's a tach filter that sits between the ignition system and the tach, in the engine bay. If it goes out, the tach does too.
And though I'm not too familier with the DIS system, I suspect some bad connections around the ignition module could cause the tach to drop out like it does on the older engines.

quote Originally posted by Jax184: There's a tach filter that sits between the ignition system and the tach, in the engine bay. If it goes out, the tach does too. And though I'm not too familier with the DIS system, I suspect some bad connections around the ignition module could cause the tach to drop out like it does on the older engines.

Not in the DIS system.
Do check connections at the ignition module, this is where the signal comes from.

Alright I'll check that tommorow

There isn't one on that version 2.5

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Not real familar with DIS either--if it has a C-500 block --go to the C-3 connector (white wire) thats the tach wire, on the 2.8`s they would get damaged/pinched by the protective cover.