Hey all. Same old wagon: EA82 2wd 5 speed 2bbl hitachi carb.

 

I've been having this problem for a while, and have asked offhand in other threads I've started, but this problem is REALLY starting to bug me. Fixing it would be awesome possum.

 

My EA82 will change it's idle speed erratically for some reason. I set it at 800 RPM, but when I come to a stop sometimes, the idle will go waaaaay low like 500 RPM, causing the engine to knock and sputter. If I put my foot on the gas lightly and let off, the idle speed will 'hover' at 1000 RPM or more. Putting the pedal to the floor and letting off quickly will rev the engine a bit, but resets the idle speed to normal, but I have to do this at EVERY damn stop I come to, which is annoying.

 

The throttle cable is NOT sticking, and the carburetor was recently replaced. BOTH carburetors did this thing. I checked the vacuum advance on the distributor by giving it mouth-to-mouth (yuck!) and it seems to be working fine. No leak-down. But still the distributor is old...

 

Could this be the distributor somehow? ALSO I have my duty solenoids disconnected because my 02 sensor is bad and needs to be replaced...gotta get to that at some point. Could either of these things be causing the bad idle speed?

Being a CA model, this should have the feedback (ECC) carburator system. Does your ECS light come on after driving for a bit? If so read the codes you get from the computer under the drivers side kick panel and get back to us.

 

If the computer does not get you any codes, then likely you have other problems with the feedback system. It's a gigantic mess in there, with vacuum lines and at least 4 vacuum soleniods, various sensors and other junk. I would start with testing the coolant temp sensor (computer output side), and the manifold pressure sensor - both seem to be pretty common failures.

 

I see that you have disconnected the duty solenoids - well have you plugged the ports and the vac lines going to them? Big vacuum leak if you do not. Also - the system is still connected into the vacuum array regardless of the duty solenoids being connected or not - the pressure sensor for example may leak internally and when vacuum is applied to it cause a leak that will lower your idle. Best to just replace your O2 and get the computer working FOR you not against you. It's LED reporting system is there to help you - both to get better mileage and to track down and repair faults.

 

GD

On my '87 dl wagon with a Hitachi, it helped a lot when I put new vacuum hoses on; the hoses with heat hardened ends can be a source of vacuum leak. It is very easy also to miss a connection or to have one or more small hoses get disconnected when working on the carb - what a mess of hoses.

Try to ceck O2 sensor......