Tach not Showing correct RPM when connected to DLC

[Gacinaz]

1994 4Runner Automatic
When I connect my tach to the IG of DLC1 it reads 250 yet the dash tach is reading 900. Is this an incompatible test tach that all of the manuals warn about or is this an ECM problem. The tach works fine on my 90 Corolla which has the same DLC1 hookup.

The truck idles fine but has no power on hills and absolutely no torque.

New Head Gasket
I have replaced the TPS and adjusted it. (it was bad)
Cleaned the TB and reinstalled with new gasket.
New plugs and wires
Compression 130 to 135, not great but
New ECM temperature sending unit, old one totally corroded inside
Measured resistance on Knock Sensor and cold start injector
replaced vacuum lines
checked O2 sensor
New fuel filter
Checked fuel pressure right on spec
Maf checks good

Anybody got any ideas?

[jetwhine]

Gacinaz,

I don't think it would even idle at 250, just my guess. On the power I would check the timing.

[Gacinaz]

That's the problem. It idles fine and the dash tach shows the correct 900 but when I connect to the DLC it shows a different low reading. The timing is set at 11 degrees.

[jetwhine]

Gacinaz,

With TE1 and E1 shorted it should be 10 degrees btdc. It is only one degree off but it could make just a little difference.

[fourwd1]

Have you tried connecting the tach to the ign coil to see if it reads correctly?