BC

What about on the LH systems?

PorKen

I dunno, the factory deleted them in '83 on US autos. The pic above is of ACG's untouched engine, with factory caps.

They aren't cheap these limiters, and many are too sensitive from age. Also, if you remove the PCV, and vapor recovery systems, it will push an old one over the edge, and will make the idle variable.

My '86 blows some a puff of blue smoke (valve guides?) after a dyno run, so maybe I should put a 16V vacuum limiter on there (same part# for K/L/LH).

karl ruiter

I think they are not needed on autos, since you cannot really compression brake. ..Although if you are really hitting the BWAAA and you suddely shut down you might still pull a lot of vacume. The one from my '79 4.5 motor had an adjustment on the release point. I had to fiddle with this to get the idle under control.

Johnny G Pipe

Just to add to this thread, I had the same over-run smoke, which has gone now since I have re-fitted my previously deleted deceleration valve..79 euro 5 speed.

This thread fixed my issue..thanks

karl ruiter

Glad to hear it. However, I'm sorry to report that it may be a sign of other issues. Sometime in the last 13 years I pulled that motor apart and found the piston rings were brittle and some had broken. None survived being taken off the pistons. Not quite sure why that happened and I have never seen it before. I ended up replacing the block, pistons, and rings. I'm not sure, but I think I am currently running without the decel valve, the problem with this being only that, after decelerating to a stop light, the idle will drop for a while, then come back up. Sometimes enough to die.
My thought would be to drive and enjoy your car now that it is not billowing smoke, but keep an eye out for a motor you can buy right and go through at your leisure. Some parts (head gaskets? Rings?) are stupid expensive, but if you have time to troll you can get them cheap. For example, I got my factory new 4.5 block with pistons and rings for $300 off ebay.

SwayBar

What a score - what's the story behind that?

karl ruiter

Don't really know the whole story, but I'm thinking some dealership or parts distribution center had it sitting around for 30 years and decided they wanted to free up the space. Long since off the books and just wanted it gone. I know it was a replacement block, because the serial number pad is raw casting with no numbers, and I was the only bidder. This kind of thing can happen for me if I am patient and watch over a long period of time. I got my GTS stupid cheap because the dealer told the owner that the head cover gaskets and pan gaskets were leaking and it needed a $10K service. Turned out the be a $100 power steering hose. That happened because I check craigslist for 928 stuff every day for years and years, I was the first caller, and I showed up in a 928 tee shirt. I'm currently trying to close the deal on a pretty nice '91 that was offered to me for $1k. If there's an art to being a bottom feeder it has to do with patience and persistence. Fortunately, to me the 928 is timeless and I like them as much as I did when I started playing with them 35 years ago, so there is time to be patient.