Hey guys...are there many 3rd gen owners on here?

I have been working the bugs out on a 3rd gen for a few weeks now and I still have 1 issues I can't quite put my finger on.

Some details about the car:

1989 Preludi Si
175k miles (original engine)

Problem: Start car...engine idles normal for about 5-7 seconds. CEL comes on and engine revs to 3k RPM accompanied by a LOUD whistle.

Using starter fluid I found a vacuum leak at the intake manifold gasket to the head. Removed and replaced that. No more leak there. Loud whistle still occurs.

After further investigation I found the secondaries are staying wide open at idle. I'm not getting vacuum to that line. Using the Helms I tested voltage at the bypass valve solenoid and accoring to their flow chart the solenoid is faulty.

Has this occured to other 3rd gen members? I have a used, but supposedly still good, vacuum box assembly coming with that solenoid. Just looking for other ideas/insight from fellow owners.

 

yup, lots of 3g owners out there. not many on this site though. check out preludepower.com
the iab solenoid failing is a common problem with 3g's due to how they are wired: contant voltage at low rpm, no voltage at high rpm. which is the reverse of newer engines that use iab's.

have you checked what trouble codes are stored? the iab solenoid usually doesnt throw a code if it fails, so you probably have something else wrong. and the iab's sticking open wouldnt cause a whistling or a high idle

 

haha actually the CEL puzzled me for a bit. I couldn't figure out why it was coming on but when I turned the key to the 'on' position it would not flash a code. Then I read that you need to count the flashes from the LED on the ECU. That is part of tonight's work.

 

good luck man, report back with your findings

and FWIW i have a 3G and a suzua AP1 :D
/OT