I'll remove the booth/flex wrap that I have on it to check that out however since I can make it run OK by just varying the amount of air going into the MAF with my hand I assume it's OK.

 

Isnt there an O-ring both above and below the maf? (bottom one which i was referring to) I know theres definitely one in my 84 to seat the AFM. At work right now so i cant find a PET diagram to confirm
hope this helps.

Jonathan.

 

Johnathan,
On your '84, there is an O ring. On an S4 and above, a MAF boot "replaces" that configuation.

 

My bad . Thanks for clarifying!

 

Well I started and ran it few times through the adapter mode with the "Hammer".

Checked and cleaned the MAF connector and than drove it around for a while still getting the same results when stopped she idles at 1275-1350RPM so it looks like I do have an air intake/vacuum leak some where under need the intake.

So in order to resolve this issue I guess the intake refresh job I anticipated to do in 1-2 month may have to be advanced.

It would be nice to know what has failed before pulling the intake but it's hard to see under the intake with everything in place.

I'm not going to start on this until I have completed the refresh (paint) of my backup intake/valve cover set.

Again thanks for all the efforts to help and if anybody has some other bright ideas let me know.

 

use an inspection mirror on the plastic connectors that plug into both sides of the MAF boot.
mine had a small chunk missing and it was only visible with the mirror they are a PITA to re-place but new parts should be installed, they are pretty inexpensive.

also make sure that there isnt a leak in one of the vent hoses that go to the elbows on the cam covers

 

Stan

I spend some more time with the inspection mirror so far I noticed the lower hose on the "Y" at the passenger side has the screw head of its hose clamp facing the "V" of the block.

Did you manage to replace it with the intake in place?

I'll check the hoses, is the vacuum line that runs to the canister valve an open port into the throttle body?

Some time ago I made up one of those gismos that is used to apply a little air pressure through the MAF into the in take. Dwayne has pictures of it in his write up of the intake refresh and writes that it slowly looses pressure over a period of 4 minutes I have tried that but it has not worked for me air gets out through the cam vent hoses right away.

What am I doing wrong?

 

the plastic connectors will pull out of the boot .

you can check the canister valve see if its closed or open then apply 9volts to the contacts see if its condition changes.

also inspect the hoses by the brake booster maybe you jostled one loose ,

check the 6 way splitter for a vacuum leak its possible you removed a hose.

remove the flappy hose from the front solenoid and see if the flappy opens with a mytivac,
then with the rubber cap removed start the car see if the flappy is moving when you start the car

 

Since you were working on on of the coolant hoses just before this problem started, did you check the gas vapor recirculation switch/valve hose fitting that is right below the front of the waterbridge? If it came apart, that would serve as a vacuum leak into the throttle housing.

Yes. You would check whether that line is still connected to the throttle by checking for vacuum on that line when the car is idling. What is your idle vacuum reading? There is one vacuum line on the bottom of the throttle and two on the top. One may have come off, although with the idle RPM as high as you have, it seems like something more substantial. The bottom one usually goes to the air pump diverter valve, while one of the top lines goes to the canister valve and the other goes to a 4 or 5-way that feeds the fuel pressure regulator, dampeners, and auto trans if present.

 

Bill I will check that in the morning I was working around the coolant reservoir putting in a piece of longer hose from the reservoir to the pressure switch as the washer fill neck was to close to the hose clamp on the pressure switch.

 

Yes you’re right the bottom one goes to the air pump but in my case is capped off as I have removed the air pump. The canister one seams to be connected as well as the one to the 4-5 way I have a vacuum gauge but have not used it to test vacuum on any of these lines and that’s a good idea that I’ll also will try in the morning I appreciated that tip I didn’t even think about putting the vacuum gauge on.

Thanks

Does the canister valve have diaphram inside that could be leaking?

 

Herman,

You are almost certainly looking at a leak in the inlet system given your description ofa more stable tickover by putting your hand over part of the MAF.

I dare say it could be something else but no idea what. The idle stabiliser can only do so much once it is by-passed.

In your position I would have the inlet manifold off and find the culprit. I have had the inlet manifold off and back on again in an evening so it is not the biggest of jobs- just a PITA.

Good luck

Fred

 

Fred I agree with you since it runs perfect with just 1/3 of the MAF intake covered based on Bill’s and Stan’s last comments I’m going to put a vacuum gauge on each of the lines with the engine running and if that that turn out negative than I’ll take the intake of I’m not that concerned about the time frame that it will take just that I have an alternate set of top end stuff (manifold, cam covers, water bridge and metal oil filler neck) that I like to put on at the same time but so far I have not located a Soda or Dry Ice blaster in Dallas.

Thanks for you input.

I wish you well

 

Herman.....there are 3 ports on the throttle body and 2 plastic connectors on the rubber piece between the MAF and tbody.....all can leak.

Given where you were working I would begin my search there per Bills recommendation; the air diverter or the carbon cannister both of which are fed directly from the tbody. To verify the other end of these hoses are coonected properly to the tbody check for vacuum with a guage, engine running.

The same checks can be made of the third vac line off the tbody which goes to the 5way splitter.

 

Yesterday I had another look and I found that the bottom rubber elbow (the hose that runs to the air pump diverter valve – in my case capped as I have the air pump removed) had come of the throttle body – I managed to remove the rubber connector that fits between the MAF and throttle body with the intake in place on the engine (ask me how) – after replacing and reconnecting the hose with the engine running it pulls 21 Hg on that line.

However I get 0 Hg reading from the line that runs to the canister? The connection on top of the T-body looked good and blowing on the line I could hear the air come in to the T-body – however not getting an vacuum reading make believe I may have to go back in there and replace the hose and connector.

Before I’m going to do this today I’m going to check the gas vapor recirculation switch/valve hose fitting and take a vacuum reading on the 4-5 way that feeds the fuel pressure regulator.

The splitter that serves the HVAC system reads 21 Hg