emissions repair questions for an 87 5ktcs

Enzeder enzeder at comcast.net
Sun May 4 18:08:25 PDT 2008

I think that buzzing is from the CIS frequency valve.  There is a 
test that can activate this and other fun stuff: 

Another thought is the ECU temp sensor:
if it thinks the car is cold, then it will run rich.

And it's easy to clean the ECU ground wire:
Probably not an issue, but I've learned over the years to start with 
the easy stuff.

At 04:06 PM 5/4/2008, David M. Yentema wrote:
>As Huw said, I meant the cold start valve, but i'm not convinced  that is
>the problem... Same with the ISV, i tested it today, and it is working fine.
>I think it might have something to do with my ignition system. the
>connectors on my coil are corroded slightly, rotor is worn, and the spark
>plugs are the wrong ones. I put the dual electrode bosch plugs in there
>before i new any better...
>One other bit of info, sometimes when sitting at a red light or something,
>the car will sound like it is missing horribly for a few seconds and during
>this the fuel distributor buzzes at an irratic rhythm

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