High idle...no cel

[rah rah 986]

I just got my '98 put together after having it apart to do a laundry list of maintenance and repairs including valve job; Ims; Rms; aos; coolant reservoir; cam to cam ramps and chains; o2 sensors; clutch; and a variety of seals.

The car started right up with minimal clatter or smoke, and I am encouraged that I am headed in the right direction.

As of right now, my only issue is that the engine is idling at around 1000 rpm. It is smooth and steady, but higher than what is normal for my car. Prior to my tear down, th engine idled at a steady 700 rpm.

The reading that I've done suggests a vacuum leak could cause an elivated idle. Can I have a vacuum leak without having a code thrown?

Also, since the engine was apart and needed retimed, is it possible that a timing issue could cause an elivated idle? I can say with confidence that I payed special attention to timing procedures that I found outlined on this sight and others. All marks were dead on, and checked again, again, and....

Looking forward to your thoughts. Thanks

[jcslocum]

That's a huge list of repairs!!

The ECU needs to learn for a while to get the settings right, so be patient as you search for vacuum leaks. It may settle down but with all that work on the heads, you may have a new idle.

You can make a smoke machine quite easily to test for vac leaks.

[rah rah 986]

Originally Posted by jcslocum

That's a huge list of repairs!!

The ECU needs to learn for a while to get the settings right, so be patient as you search for vacuum leaks. It may settle down but with all that work on the heads, you may have a new idle.

You can make a smoke machine quite easily to test for vac leaks.

Thanks for your post. I'm interested in the smoke machine. can you describe how to make it? I'm sure many of us would be interested in having access to a smoke machine.

Well, I spoke too soon about being cel free. Shortly after starting this thread, my light came on. P1123, p1125, and p0506. The good news is that the light was off long enough that I was able to pass my emissions enabling me to get my plates.

[Gelbster]

You can find Smoke machines on EBay but they require quite some knowledge of the M96 vac system to be effective.I have one. I find a propane tester (You Tube) to be much faster and easier to use. You just use a small can of propane with a hose and wand. Obviously you don't light the propane!
A good example is finding a leak on a badly fitted cross tube - the flexible connectors that go between the banks.Easy to poke the wand under there and produce a rise in idle speed.Good luck doing that with Carb Cleaner!

[jcslocum]

I made on with a 1 gallon jug, a fish pump and a cigar. Cost $.50 to make, those little cigars stink!! Air in the bottom, goes thru the cigar, makes smoke and the rubber tube from the top delivers it to the intake. Ram a rag in the intake after the air cleaner and the same into the exhaust. Smoke will come out at the leaks. We only used 1 cigar from a box of 3.





Works a treat!!! Found our vac leak. Lots of youtube vids on the subject.

[rah rah 986]

Thanks. I'll give that a try.