05-25-2017, 03:23 AM
New to me 97 Sport 1.8l. Clean southern car with nearly NO RUST!! YAY!! I'm in the NE US & everything here is rusty...
This 1.8 starts cold perfectly, holds 1500 RPM's for ~45 seconds, drops to 1200 RPM's as it should. Then it will start to drop out, instantly dropping 2-300 RPM's & sounds much like a misfire. It then keeps doing the same 'drop out' once fully warmed... it will hold 800 RPM's then suddenly drop to ~600 randomly... then right back to 800. The ECM is showing no misfire (or any other) codes.
It does not seem to 'lope' like an air/fuel issue but happens suddenly, almost like it's losing power, but again it's not throwing any codes.
I did read the 1.8 idle page here. I have pulled the ISC connector while running, & it dropped rpms to ~4-500 & kept running at that super low idle just fine... with no jump or drop. Reconnect it while running & it jumped to ~1500 RPM's & then settled back & 800 & started dropping out again.
I have inspected vacuum lines & found no obvious issues. I have not yet done a propane check.
I did put my analog multi meter on the ISC & it reads 1.4 ohms, though it may be actually 14 bc the meter defaults to Kohm scale. It reads the same if I reverse polarity. I have not yet tried to hotwire the ISC as I don't have any alligator clips atm.
It only does this at idle, while at speed there is no noticeable drop/power loss etc. It does occasionally stall in gear coming to a stop, but seems to have no issue while moving at any speed.
Thoughts/Advice/Next step?? Thanks!
This 1.8 starts cold perfectly, holds 1500 RPM's for ~45 seconds, drops to 1200 RPM's as it should. Then it will start to drop out, instantly dropping 2-300 RPM's & sounds much like a misfire. It then keeps doing the same 'drop out' once fully warmed... it will hold 800 RPM's then suddenly drop to ~600 randomly... then right back to 800. The ECM is showing no misfire (or any other) codes.
It does not seem to 'lope' like an air/fuel issue but happens suddenly, almost like it's losing power, but again it's not throwing any codes.
I did read the 1.8 idle page here. I have pulled the ISC connector while running, & it dropped rpms to ~4-500 & kept running at that super low idle just fine... with no jump or drop. Reconnect it while running & it jumped to ~1500 RPM's & then settled back & 800 & started dropping out again.
I have inspected vacuum lines & found no obvious issues. I have not yet done a propane check.
I did put my analog multi meter on the ISC & it reads 1.4 ohms, though it may be actually 14 bc the meter defaults to Kohm scale. It reads the same if I reverse polarity. I have not yet tried to hotwire the ISC as I don't have any alligator clips atm.
It only does this at idle, while at speed there is no noticeable drop/power loss etc. It does occasionally stall in gear coming to a stop, but seems to have no issue while moving at any speed.
Thoughts/Advice/Next step?? Thanks!