Another 3.2 idle issue

[Quicksilver]

Originally Posted by GK81

A DME car will hunt upon start-up after the battery has been disconnected. It has an Adaptive Memory. After driving it this hunting goes away.


However, what the OP is describing sounds like a vacuum leak. I think if the idle micro switch is open the idle is much greater then 1000.

To be a little more to the point than Steve.

There is no RAM or RAM like memory in the 3.2 DME. It is very simply a "read the sensors and look up the values in a table" engine management computer. No magic involved.

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No one has mentioned the intake manifold as a source of leaks. A way to check is to get the car up on jack stands while dead cold. Start it up and use an IR thermometer gun to read how equally the various exhaust port temperatures rise. If the intake manifold gaskets are the issue you will see the effected port(s) heat up a lot slower because they are sucking straight air instead of air-fuel mixture. 18-ft/lbs if I remember correctly.

If they have been loose the gaskets probably cracked so they'll need replacing. Each port has 2 gaskets and a plastic "thermal" spacer. (The spacer will have eroded over the years so you will want to replace them.)
If the fuel line to the injector rails hasn't been replaced, while the manifold is off it is the perfect time to replace them.

[msterling]

Steve W. will always offer accurate advice. I have one of his chips and his instructions had me checking the operation of the microswitches before making any other adjustments. I still suspect a vacuum leak is the most likely issue. Previous botched service is often difficult to unravel and Steve makes a good point in his post.

[86911cab]

I had the same issue with my 86 It was a broken gasket at the intake runner spacers it was a broken gasket at the intake runner spacer