'88 5kcstq overboost, racktime again

[Ken]

Well, I'm pretty sure my '88 5kcstq has a torn WG diaphragm.

I recently posted that it was getting more boost than it should, and that sometimes the boost is a bit "chunky".  Coming off throttle after high boost too quickly was causing some oscillation/stumbling type of behavior.

Well, this morning I confirmed that my car will indeed make as much boost as I desire.  I just about pegged my 20psi gauge briefly!  I don't think I broke anything.  I guess that verifies that my TAP ecu doesn't have much in the way of overboost fuel pump cutoff.  If only I had insight to the air/fuel mixture or exhaust temps, then I would know if I'm going way lean with the stock system.

Btw, what does knock sound like anyway?  Is it a bunch of repeating noises in quick succession?  Occasionally under certain circumstances I hear a noise similar to that when boosting, and I had previously thought it was the leaking exhaust manifold.  My theory was that somehow the exhaust backpressure is higher under boost, and it was coming out the leaking EM.  But I might be hearing knock for all I know.  Any sound files of knock on the web I can listen to?

And of course, I think my rack is indeed leaking now.  This is the rack from my donor car, after having the hydraulic lines briefly hooked up backwards upon installation.  If it is the rack, I'm not all that sad about it.  The rack replacement was minor in light of the clutch job, and the rack from the donor was already a used rebuild with unknown history.  The donor was bought for the motor, and the rack would have been a bonus.

I'm thinking the rack won't be so bad, since I was in there doing it before, and have a pretty good understanding of what is in the way and how it needs to come out.  I'll be going for a Jorgen replacement.

Part of me wants to investigate retrofitting a older non-high pressure hydraulic steering rack and system, like from an older car.  I wonder if it's worth it tho', since it seems people have good luck with their Jorgen rebuilds.  I don't have much info on this retrofitting deal, for example what happens with the brake booster side of things.

On a positive note, I got my 4ksq moved into the garage ready to start working towards installing the MC-1.  This weekends priority will be to get the swamp cooler replaced so the garage is cool for this summer.

Later,

Ken