Hi All,

I have been pretty successful with my stalling problem. I found a bunch of things that would definately contribute to crawl & stall. Corroded terminals on airflow sensor, disconnected vacuum line, loose valve cover(s), loose spark plugs, etc. I am sure glad I went digging around in there. Car does not stall anymore.
Thanx for all the help and direction from my fellow sharksters. Simply would not have been possible without your input.
QUESTION - How far down is the airflow sensor supposed to seat itself into the intake? It looks like it should slide down further then it does. There is a lip on the bottom side of the sensor and it looks like the sensor should slide into the intake until this lip sits against something. The sensor is tight up to the bottom of the air cleaner but I can still hear a hiss coming from down there somewhere and I am wondering if the sensor is properly seated. Can't find any clear info on this in the manual.
Any help would be , as always, greatly appreciated.
I also have to replace the axle boots on my shark. Is there a good writeup on this procedure on anyones site? My main concern is getting things back on where they are supposed to be.

Thanx Again All

 

Hi Bernie,

2 sealing rings at bottom of Air Flow Sensor like this:

One is an inner doughnut which the MAF fits into and the other fits over the MAF. The MAF should fit all the way snug. Don't over-tighten the clamps. Make sure that the studs are coming through the airbox holes where the hold-down nuts fit.

Greg

 

Hey Greg,
Thanx for the reply.
The doughnut that the MAF slides into is there but I am pretty sure that's it??
Would this MAF sealing ring go over the outside? Seems to make sense? Can't seal anything on the inside?
I think someone omitted this other ring when they changed out the MAF. It is not the original (has markings on it)
As far as proper assembly is concerned, should the MAF be placed fully into the intake first and then the aircleaner bottom on last? When I took it out for a checkup, the whole assembly came out together. The top is clamped but the bottom just slid into the sealing ring in the intake. Should I seat the MAF and then slide the aircleaner over to just set the proper height for the top gasket/clamp combo? Or does the top side get mounted first and then slid into the intake.

Greg, you have been a big help with me and my Shark. Lots of replies and I really appreciate it. Hope to meet up with you someday for a big old handshake.

Cheers Mate

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

Bernie:

[quote]Would this MAF sealing ring go over the outside? <hr></blockquote>

Yes. Looks like a big O-ring. fits aroung the MAF and seals it to the airguide housing.

The other sealing ring, which I referred to as a doughnut, fits into the airguide housing. You should see a recess for the seal to fit into. Then the MAF (with it's seal in place) fits into the airguide housing.

[quote]As far as proper assembly is concerned, should the MAF be placed fully into the intake first and then the aircleaner bottom on last? <hr></blockquote>

Yes

[quote]Should I seat the MAF and then slide the aircleaner over to just set the proper height for the top gasket/clamp combo? Or does the top side get mounted first and then slid into the intake. <hr></blockquote>

Set the MAF in. It should got all the way to the seal. Set the both clamps and the boot over the top of the MAF. In my case., the boot is flush with the ring on the maf (as far downas it can go). Set the airbox (don't forget to hook up the temp sensor plug) onto the MAF. There is a large hose on the right side of the airbox bottom which needs to be attached (small hands and a cool engine help here). You'll see the nipple on the airbox bottom, and the hose near the coolant reservoir. As I mentioned in a earlier post, make sure the studs come throught the airbox housing. With all of that done right, the airbox should go well into the top part of the boot. Mine is fully flush as far down as the housing can go. Tighten (but don't over-tighten) the two clamps.

Bear in mind that the only thing holding the MAF in place is the airbox mounting nuts attached to the two studs. Without the nuts, you could pull the whole shebang straight up and out. Not good for sealing false air. Make sure the nuts are in place and snug.

I just ordered new seals and a new boot for mine today. All part of the total rubber renewal process I believe my 86 needs being 17 years old. Another thing for you to consider is a renewal of the intake boots accross the top of the engine. I did mine and noticed a improvement. The PO had bits of radiator hose there (dope!).

Let me know if I can help amy more.

Greg

 

Hi Greg,
Phoned 928Inter. for the outer sealing ring to the MAF. Jim said he should have one in for me by Tues / Weds....
I went back in to take a look and found a couple of extra things. Another broken vacuum line running from the multi connector towards the fuel actuator at the front of the engine. I have no doubt that I probably knocked and cracked this plastic line while messing with the MAF

Also found a intake booty with a sizable crack in it so I guess I need to add a new set of those to the order as well.

There is definately no way the MAF was seated. I had to use lube to get it past that doughnut. I still need the outer ring but at least its in the engine....

Problem now is, engine is back to stalling - dammit. I guess me and the mityvac are going to become good friends for awhile.

Does the vacuum for all the AC functions separate from the engine vacuum? For the purpose of isolating the leak, could I simply plug the vacuum line(s) that run to the AC components and concentrate my efforts on engine related vacuum?

Cheers
Bernie

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

Bernie,

Are you familliar with the procedure to cover the MAF with a innertube and lightly pressurize?

If not, let me know and I'll find the link for you. It's also spelled out in the shop manual. It's no doubt the fastest way to find some of those leaks. I did it and was quite pleased.

Also, you'll find an improvement when you relpace those intake boots. Mine loped when idling, stalled, etc. The intake boots and the vacuum leak I found with the innertube put an end to that.

Greg

 

Hey Greg,
Yes, I know the test using the innertube. There may be multiple leaks so I am wondering how to isolate different vacuum areas. I will be using the tube along with the Mvac to try and track this down.

Thanx For the help.
Off to work I go

Bernie

 

Bernie,

Pulling the blue/black check valve and plugging the nipple on the brake booster will remove cruise, ABS (if equiped) and HVAC. Take the line you removed, and use the mityvac. It may take a few pumps. See if vacuum holds at about 16.

If vacuum does not hold, isolate and plug HVAC line (goes to firewall) try again. If still bad, do thesame thing with the 2 lines running into fender, one at a time.

Also, the blue/black check valve is a funny animal. Mine was buzzing, I cleaned it with carb cleaner and it has worked for a few months. It now causes a drop in vacuum which is effecting my HVAC. I can put a vacuum gauge on it and pull through it with the mityvac. There is a substantial drop. Mityvac shows 16, gauge on other end of valve shows 10. I'm pretty sure that 10 will not allow HVAC flaps to operate properly. Time for a new check valve.


Before isolating anything, I would pressureize and listen. When you hear something, isolate or repair it at that point. Then pressurize and listen again. Light pressure, don't want to blow anything off it's fittings. If you have an automatic, the vacuum line from the engine to the trans. is often suspect. Breather line on engine was my biggest leak.

But again, I would pressurize and listen first, then chase down what you find.


Greg

 

Thanx Greg,
That's good info.
I probably wouldn't have figured that I would blow lines off their fittings by pressurizing the system. That would have been a live and learn event. LOL
Now the transmission vacuum is an interesting one. I always felt that my AT was shifting a little hard and I have read about shift stiffness with regards to vacuum leaks in other posts.
I will definately get back to you on my results. The good news in all of this is that one of my friends at Socal928 (Eric) has helped me to eliminate the idle stabilizer as a possible culprit. I also heard that it could also be valve seals? Hope it doesn't go there.....

Talk Soon
Bernie
<img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />

 

the next event at dave and jeanies is going to have my smoke machine at it. best tool for 928 air leaks i have ever used. if you can find a tech with one in the meantime do check it out,they are awsome. joel