Diagnostic help - engine hunts

[JohnT]

Got the turbo engine running ok in the Civic body (we previously had a wire missing off the air inlet temp sensor which is fixed now)

Starts reasonably easily but hunts between 1,000 and 2,200 rpm on about a two to three second cycle.  Tried disconnecting the idle up solenoid, which was clicking away, but didn't stop the hunting.  Oddly enough, it seemed marginally better with the fuel pressure regulator vaccuum/boost line  disconnected.

As the engine warms up the hunt flattens out a bit, but still there.

Any bright ideas?

John

[Turbo3]

Yo John,

It seems as soon as there's any sort of air leak in the system, this is the result!
Check all the tubes going to the ominous black box for leaks or any sensors not properly earthed.

Pete

[JohnT]

Thanks Pete for the suggestion - quite right it is an air leak - actually a slightly misaligned throttle plate.

John

[PGNUTA]

If the vacuum advance canister is stuffed it will cause this.  Look for the thing of the end of the disributor with the two hoses going into it.  Pull these hoses of and block them up.  If the problem goes away then there's your problem.  Get a new one of those although i think they are quite expensive.

That was the problem with mine anyway and it was doing exactly the same thing.

[JohnT]

Thanks PGNUTA, but I found the issue - the misaligned throttle plate. We have a nice distributor with intact diaphrams, which was why I was very puzzled at the subtle air leak.

John

[Henry]

John T. think you are in Adelaide, want to compare notes sometime?  Henry

[JohnT]

Henry

Absolutely. I'm contactable at [email protected], or ( 08 ) 84189100. Not often in. mind you, but ....

John