Hey all,

Back in the US. ?Got the car put of storage. ?1979 with CIS.

new injectors, fuel regulator rebuilt. ?Vacuum hoses replaced with silicon a few years back.

I have a surging idle when cold. ?Normally, this is the AAV. ?I have tried pinching off the output hose, but it makes no difference.

What else should I be checking?

Cheers

开云体育

Couple of quick thoughts.

Cold start injector on the front of the intake??

And CIS does not like to sit at all.? Even if the parts are all new, it gets finicky.?

I'd toss some Berrymans into the tank, jumper the fuel pump relay and cycle fresh gas through the system.? Make sure you have a charger on your battery.

It won't help the cold start injector so you may have to pull it and soak it or replace if necessary.?

welcome back...

开云体育

Hummm… 500 miles, that just about R/T up to you’re place Colin.

Colin,

I did a quick check on both the thermotime and the cold start. ?They appear to be working properly.

I do think a drive is in order.

Does this car have an oxygen sensor, or purely mechanical CIS? If the former, a bad ground (at the sensor or, more likely, at the feedback control unit) can mess with the accuracy of the feedback provided by the sensor, and have the frequency valve constantly overcompensating and oscillating back and forth rich/lean.

Joe,

Pure mechanical. ?Not even a connector for the fuel consumption gauge

I pulled the AAR. ?The connections were corroded, so I cleaned and de-oxed. ?It is getting 12v to the connector. ?The valve itself tested to work properly with cooling and heating.

The surge is mostly gone now.

Checked the vacuum work I did a few years back. ?Deleted the EGR and the amplifier. ?I also deleted the air pump, and removed the blowoff valve. I found the diaphragm for the dizzy vacuum advance was leaking, so I replaced ?that.

I did leave the decel valve in place. ?However, I remove the barometric valve. ?


One stupid error from my previous work. ?I left the connection from the back of the throttle body to the thermal valve (EGR) switch connected, but didnt blank off the other port on the switch. ?Capped that this morning.

I also found the vacuum line from the dizzy I had hooked up to the front port on the throttle body. ?That connection is for the dizzy retard. ?So I ran the line for the advance to the back of TB where it should be, and capped the front port.

I have checked the vacuum hose connections for both sides of the AAR, and they are tight. ?Both vacuum and atmospheric lines for the check out for tightness.

I have also adjusted the throttle plate screw to time the injectors via the opening pop of the injectors.

Now, I have a warm idle of around 1100 that I cannot bring down with the idle adjustment screw on the front of the throttle body.

Normally, this would indicate a vacuum leak. ?But having gone over the entire vacuum system, I cannot see where it would be coming from.

Any suggestions?

Update,

I found the barometric pressure sensor (#2) and put it back in-line between the throttle body and the decel valve (#3). ?Part throttle smoothed out, and this high idle came down about 200 rpm.

I had the fuel distributor rebuilt a few thousand?miles ago. ?I replaced the large gasket on the plenum

But not the O-ring under the throttle body. Imcan see that being a source of a vacuum leak. ?

Does this go bad?