Tach not showing correct idle speed
09-18-2011, 02:48 PM
#1
Registered User
Thread Starter
Join Date: Aug 2011
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Tach not showing correct idle speed
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?
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?
Thread
Thread Starter
Forum
Replies
Last Post
