Player0

Actually, I bought the new AOS seals, but I'm not sure how I'm going to get that thing off. It looks like I would have to remove the turbo down pipe?

I got all new vacuum and many new cooling hoses, all the fixens. I also ordered the Throttle body replacement kit. Are they difficult to reconfigure? I worry about messing with any of the set screws.

Yeah, witchhunter worked great (I've been reading the forums a lot) but I had to get a replacement injector since one was fubar.

I'm replacing just about ever sensor, valve, and repairing much of the wiring. Basically keeping busy so I don't have to face the sensor bracket :P

Unfortunately, I've noticed a lot of old oil all over the engine. Not sure which gasket/seals are leaking. It's not all from the AOS.

I did do a compression test. All four are testing at 120 PSI. I think new these engines were pushing 140 PSI. I'm not sure how that number is for a 25 year old engine with 90K. But it doesn't seem terrible so I think all this effort is worth it.

John_AZ

120 PSI is good on a used turbo engine.

Oil leaks on the top of engine can be a combination of AOS seal leakage out of the TB intake boot.
Cam housing cork gasket at the end of the cam housing is a normal leak.
Cam housing seal.
Dried fuel leakage from the injectors before you had them rebuilt.
Front cam seal
You may have some oil leaking from the oil cooler plate on the engine that is being forced up top.

GL
John

Player0

UUGGHHHHH finally got the bracket out. I gave up the hex wrench socket route and all I succeeded was rounding the inside of the hex head to bits, so I went to lowes and bought a cold chisel. I finally smashed the damn bracket out.

Now for the aftermath:

Some threads came out with the hex bolt. I was trying to snap the head off the bolt, but ultimately this just ended up pulling the bolt out with the threads.

A small shard of the engine block also broke off. This was part of the block directly beneath the allen bolt. It has maybe a thread and a half on it.

The bolt still threads in, but the threads will definitely need a repair. I was thinking of ordering a thread repair kit anyway. Should I go for the repair kit or go directly to a tap and die kit?

I'd like to avoid putting a new allen head bolt in this spot. Are there other bolt styles that would work here? A hex head or something?

Also, what is the exact size of this bolt anyway? Since I stripped the threads some, should I get a longer bolt?

The third sensor on the bottom of this bracket, what is it for? Doesn't seem to have a connector, just a wire directly in to the harness.

There was a small shim under the speed sensor on my bracket. The reference sensor has a bit of an offset. I figure I should reuse this shim. When using the shim, do I still need to gap 0.8mm?

Glad I had carpal tunnel surgery, or I'd be crying good today

Player0

Oh, looks like the bottom sensor is for Top Dead center. I thought that's what the reference sensor was for.

And its an 8x25mm pan head according to the spec sheet. Still not sure if I should go longer just so I can be sure I have threads. And anything other than an allen head would seem to be a good idea since they just strip like crazy.

John_AZ

I do not know why you would have wanted to chisel the head off a heat treated bolt attached to an aluminum block.

The idea was to break up the sensor bracket in pieces--softer.

Please take a picture of the shard of the block that chipped off.

Yes, use a metric hex head bolt the same pitch 8.8 and length of the old bolt.

I do not know if the hole is deeper--measure somehow.

The third sensor is a factory TDC sensor used in the build and factory testing. The part is NLA ---not needed. The wire usually goes to the rear of the cam housing by the engine lift bracket. Save it! The 924/931 guys want it.

The reference sensor has a small pivot collar in one of the bolt holes. This is necessary used to gap. Do not remove.

Late reference sensor brackets also had a sensor "sheild" in one of the holes.
The design was to eliminate some electro magnetic pulses from the high torque starter that would interfere with the pickup of the reference sensor. Keep the sheild if one was in the old bracket.

Threads

I would just try a heli coil thread insert to keep it simple.
Again, you only have one try to repair the threads--caution and go slow.

You might do a Time-Sert repair in the future.
http://www.timesert.com/html/faq.html

You have to regap to .8mm See Clarks for info.
http://www.clarks-garage.com/shop-manual/ign-02.htm

Get a similiar replacement sensor bracket from WTB parts section in the Renlist or Pelican forums.
Member Plyhammer does a lot of parts cars and may have one.

GL
John

Player0

Some pictures of the carnage. As for why I went after the bolt head, just plain old ignorance I guess. Included a picture of the bracket that shows just how much corrosion was in there. It took another hour of beating on the bracket with a vice and a hammer to get the old sensors out. I ordered another bracket already, but I think with some sanding, and since the third sensor isn't required, I could probably make this one work. Hmm.

John_AZ

Yes, a lot of corrosion. Usually caused by the heater control valve leaking.

Use some antisieze on the bolt threads and in the sensor bracket hole where the 2 sensors go.

I see the "spacer" you mentioned--the washer with a big and little hole.

You still need to gap the sensor.

GL
John

Player0

It's a good thing I got a new control valve then. I spent all evening on the dremel cleaning up the bracket (and then I got productive and did the intake manifold while I was at it). It cleaned up pretty good but the corrosion was much worse than I had imagined. It looked like there was a layer of 'glue' on the inside.

I've heard mention of a sleeve for this bracket. I didn't seem to have any sleeves on mine. Unless its the offset portion on the reference sensor side. Not sure if that's one piece or not.

Bought some helicoils tonight. I also found some M8-1.25 studs. I'm actually thinking of putting a stud in place. Looks like the nut and socket will fit here. What do you think, do you think this will make life easier?

I figured worse case scenario, since I'm probably not going to be able to drill this thing for a heli coil, if the threads are beyond repair, I may just JB weld a stud in place. If it has to be drilled out later anyway with the engine pulled, a little JB weld isn't going to hurt it anyway. This bracket doesn't need a lot of torque either I think.

John_AZ

Part 31

http://dcauto.gotdns.com/illustration/index/203490748

Remember to do the AOS seals

John

Player0

It's alive! Thanks so much guys, I couldn't have done this without you. Special kudos too John_AZ who must work here or something.

I found out today that I can develop over 2 bar of boost. Luckily I only did that once. This is a good reminder that after you rebuild your boost controller to set it to the lowest setting before installation.

Anyway, what is the maximum safe level of boost for this car? I've seen mixed reports but they mostly seem to point to about 15PSI. Maybe 18PSI.

That's about 1.1 to 1.2 bar. When I first bought the car, it was set to 1.5 bar, about 22PSI.

Again, this is a 86 944T with a Autothority MAF, larger exhaust, dual port lindsey wastegate w/ boost controller, and the K27-8 turbo (I guess).

The turbo is capable of making some seriously high boost but I just need to know the upper limit for this setting before my head gaskets blow to pieces.

Thanks!

Player0

Wow, it's really like driving a different car. Idle problems totally gone. No hesitation at high RPMs, and its just a lot more responsive.

I think the only issue seems to be that the heater valve is stuck in the on position. I'm about to go read up on how to correct that. The valve's arm is free and i can wriggle it back and forth, but it always snaps back in to the full on position. Does this thing default to full on if there's a problem with the vacuum line?