streetpirate
NAXJA Forum User
- Location
- Oregon City, OR
'87 always runs cold?
I bought a REM to diagnose this and I'm stumped. The dash gauge and the signal from the cts show that the coolant only ever gets to 160-170.
I put in a new thermostat and tested the old one and it opened near 195 where it was supposed to with no change in the running temp of the engine.
The radiator and water pump were recently replaced. I can't think this has anything to do with it but I never noticed cool running before that. The jeep rarely gets driven.
The REM shows the system running in closed loop from cold, never shows open loop during warm up. I thought the cts had to show at least 130 for the system to run in closed loop?
It failed DEQ showing it was running slightly rich, but due to virus DEQ is shut down for a while and I can't try again.
My thoughts were that it was stuck in open loop because the cts was showing cold, therefore running a little rich and failing emissions. It's odd that the dash sender and the cts both show running cold, that should be impossible if the thermostat is operating. I used my trusty Harbor Freight laser thermometer on the thermostat housing and upper rad hose (gets hot so I'm assuming the thermostat opens) and the surface temps are in the 140-160 range.
So the cts must be bad? But then why is it running rich while in closed loop? Why does it always show closed loop even when cold?
Im a little stumped and wanted to see if anybody has any ideas before I start throwing parts at it. Thanks.
I bought a REM to diagnose this and I'm stumped. The dash gauge and the signal from the cts show that the coolant only ever gets to 160-170.
I put in a new thermostat and tested the old one and it opened near 195 where it was supposed to with no change in the running temp of the engine.
The radiator and water pump were recently replaced. I can't think this has anything to do with it but I never noticed cool running before that. The jeep rarely gets driven.
The REM shows the system running in closed loop from cold, never shows open loop during warm up. I thought the cts had to show at least 130 for the system to run in closed loop?
It failed DEQ showing it was running slightly rich, but due to virus DEQ is shut down for a while and I can't try again.
My thoughts were that it was stuck in open loop because the cts was showing cold, therefore running a little rich and failing emissions. It's odd that the dash sender and the cts both show running cold, that should be impossible if the thermostat is operating. I used my trusty Harbor Freight laser thermometer on the thermostat housing and upper rad hose (gets hot so I'm assuming the thermostat opens) and the surface temps are in the 140-160 range.
So the cts must be bad? But then why is it running rich while in closed loop? Why does it always show closed loop even when cold?
Im a little stumped and wanted to see if anybody has any ideas before I start throwing parts at it. Thanks.