I e tested 4 now and after 10 min none of them close completely or at all. Either way could it be because of a bad connection? Not hot enough? I know atleast one, the newest one was tested as good and is very clean. I know they can go bad inside but I do not think they all are.
But after 10 min of car at idle its still pulling air thru, suggestions please.

Phil

Yes, heat. I assume from the 12 volt source coming into it. There is an article from way back in the Club days about rebuilding them.

is that the l-jet or the d-jet aar?
I know the l-jet can be adjusted from the screw on the connector side.

Here is a link to Brad Anders DJet site. It outlines function and rebuild of the AAR

http://members.rennlist.com/pbanders/djetparts.htm

The AAR for D-jet needs two things to work on the car. +12 volts and a good ground.
If one was tested off the car and was good, I would check for 12 volts at the AAR connector and ensure the AAR is well grounded.
Tom

The AAR uses a bimetallic strip to rotate a step-cut opening. As that opening turns past the hose connection, it gradually seals off. They stop working because of two common failures:
1. electrical failure
2. corrosion

1 is harder to fix, but 2 can often be fixed with a liberal and prolonged soaking in PB Blaster or other penetrating oil. In extreme scenarios you can pop the top connection off with a hammer and mechanically work the inner piece back and forth until it's free enough to move on its own.

As long as we're on the subject. I've had 4 of them in a box. Not knowing if any of them worked. Then I came across a 12volt power supply. I set it up with 2 leads so I could bench test parts.
So I hook up one of the AAR's. Walk away and return in about 20 minutes. I want to pick it up to see if I can blow thru it. Its so warm I wouldn't want to put my mouth up to it.

How warm should they get?
I wonder how many amps the supply lead on the harness supply's? If I remember it didn't seem like the power supply had all that high of amps. Its not real big. Maybe the size of 3 DVD covers stacked together.

They get pretty warm, and the heat from the case adds to that heat to close it off all the way.

Most I have seen are just full of junk that gets in the way of the spring closing...
Even a little chunk of junk will stop the spring from coiling up all the way...so the AAR will stay open a crack.

Rich

I m going to bench test them tonight, see if the warm up and close up- but from what i am reading here and on the ander's site i think he says 10-15minute it can take to close up, i have not run the car long enough, but i will also test the 12v going to the unit from the harness and the fuses as well, and will report back.
Anders also discribes being able to change resistance to change the time it takes to warm up and close, i'm not going to mess with that but if the 12v is there ,on this new one it may be that it sat in a box for 21_+ years on the shelf, and the soaking in penetrating oil might do the job to loosen it up.

Phil

The AAR typically draws about 1 to 1.5 amps. They measure in the neighborhood of 12-15 ohms. The battery and alternator determine voltage. If you have 12 ohms resistance in your AAR and 12 volts running voltage, then you have 1 amp of current. More resistance = less current. More voltage = more current. Since most properly operating charging systems have the car's voltage running at around 13.5 volts, the AAR usually draws a little more than 1 amp.
I ( current) = V(voltage)/ R ( resistance) or I= 13.5/12 or 1.125 amps
Tom

I bench tested one with a Tek power supply, at 13.5 volts it pulled ~1.2 cold, dropped slightly after heated.

I just refurbished a couple of them recently. They were heating up so the electrical circuits were fine, but they weren't physically closing completely.

If electrically good (VOM = 12-15 ohms & it's heating up when power is applied), try the following:

1. Soak the innards of the stack in PB Blaster for a couple of days with some plugs or rubber caps to keep the liquid from leaking out of the ports.
2. Remove the caps, drain the fluid and blow out with compressed air, then fill with PB and caps again.
3. Apply power for 15 minutes. Shut off power and let it cool completely. Repeat this cycle several times.
4. When it's completely cold, remove the caps, drain & blow out with compressed air again and check to make sure the black coke residue is gone.
5. If not, repeat steps 3 & 4 again until the fluid is clean.
6. Drain the fluid & apply power for 15 minutes again. When hot, try to blow air through ... it should not pass any air.
7. Check to make sure air flows through when it's completely cold.
8. Spray a final quick spritz of PB or WD-40 in the top port to keep the shaft lubricated.

9. At some point in the future, remove the AAR and clean it out again just to keep it working properly.

Ok so I went thru and first off tested the 12v line to the a.a.r. and I do not find
Any voltage on that connector, so now what? Can I run a direct connection from the coil #15(+) or replace that harness. I just put a new Bowlsby f.I. harness on recently.??

Phil

The AAR is on the small FI harness - connected to the 12 pin connector on the AAR - pin 12. That in turn is fed from pin 87 of the fuel pump relay.

So can voltage be checked with key turned but not running or does car have to be running to take voltage reading? Fuel pump runs fine

Voltage is only at the AAR when the fuel pump is running.
Three times the fuel pump runs.
1- when key is turned to on, for about 1.5 seconds.
2- when starter is engaged
3- when engine RPM is greater than 100 RPM's.
Hope this helps,
Tom

You can check it with an ohm meter with power off. Just measure the resistance between pin 87 of the fuel pump and the spade clip for the AAR. Measure on the lowest scale should be 0 ohm or darned close to 0

I tested the electrical function using a VOM to determine if the resistance of the heating elements was within spec ... 12~15 ohms.

I used a 12 volt, 20 Amp bench power supply with a 10 Amp in-line fuse to power the heating elements.

AARs get extremely HOT when you power them up for 10~15 minutes! I used compressed air to check for full air flow when cold, and NO air flow when hot ... If you don't have a compressor, attach a short length of appropriate sized hose and blow (human lung power).

OK. so ran the car for 10 minutes- yes we are on the road and running, but the AAR gets hot, 12v and ground good, etc but is not closing so i still have idle surge at 1000-1300 rpm up and down when hot

- start cold good, idle strong 1500 right on no surge, warms up couple minutes comes down pretty fast at that point the, idle hunt begins it does not try to die outas before all this , but im sure its the open AAR that is the cause.


newer AAR - from respectable member here- this thing is in new so clean looks like concourse clean, gets hot- was in original box was obviously on shelf for really long time, i wonder if it still got stuck due to air moisture some surface rust in there? should i PB blast it?

what else can i do?

Phil

It is supposed to get hot. I would not worry about that. If it gets hot you have the second problem Andy described. Corrosion. PB Blaster might take care of that.

Take the AAR hose that goes to the air cleaner off after it is hot and surging. Put your finger over then end. This closes off the air that would cause high idle. If you still have surging ( and I suspect that you will), then the AAR is not the problem.
Tom

What is the current status of the MPS in use?

good question- i got the current MPS in a parts buy , tested by me on the vac-it hold vac, but the epoxy plug has been removed and someone has tried adjusting it, its been apart im sure, but the looks of the fasteners used to hold the 2 parts together. - my other one i had i sent back to Ecklers- Scott and i have discussed this already, on club site, and i was going to sent this one to you to set and check out but i have not got the one back from ecklers- had it for 6 months but after fighting surge, i bought a vac tester, and sure enough it failed so i called them , sent it back- that was in may- they are on "back order" from Fuel Injection Corp. in CA so i am sitting here with a questionble MPS- holds vac but..... and the other- i called and told them if i did not get it replaced by the end of the month i wanted my $299 back and my core i sent them. ( we'll see how that goes)

so if anyone has a tested good 75 2.0 d-jet MPS i can try to see if that is it i will by if it works!!!
but the AAR is still sucking air when hot- i know they are supposed to get hot if element is working- when i plug the end the idle immediately drops, almost too low, - i know i am fighting mixture and that might be the MPS now that i consider that it needs to be calibrated and someone might have messed with it without knowing how to do this.

Thanks for the help.

hey Eckler's(automotion)

So plug it in such a way that you can drive it, it is only for warm up anyway.
Let's find out how the car runs if it were closed.
Adjust the idle speed and mixture and let us know how it is running.
Warmed up it should be 100% if nothing else is wrong.
if it isn't 100% let's get it there while the AAR soaks in PB.

I tried what you suggested, scott. If i block the AAR off, as if it were closed, its hard to keep the car running, idle dies off too low and even if i adust the idle screw out quite a bit. So i imagine this indicates the richness is way off- ie. the MPS?

I had a thought on this, wondering if this makes sense.

If when i last set the timing the aar was partially open, would this not have caused the distributor to be placed different to compensate for the effect of the AAR, so now if i close off the AAR it almost kills it, and even if the idle screw is out its not there, and so i was thinking that maybe timing might not be where it should be, if i advance the distributor slightly this should bring that idle up a little with the AAR plugged(as if it were closed- when hot)- like it should be.

right now after running it 20 min last night idle was at 1100- 1250 while hunting and is running great down the road, and i could live with that - but i know its not right- with the a.a.r. half open it seems this is the best i can do - unless i can get a spare MPS to test(043).

PW

Hi Phil,
The timing is a mechanical setting indepedent of the issues we have here, but do check it.
So it is still surging indicating a lean condition? Does adjusting the idle mixture on the ECU have any effect (even if it isn't the desired one)? No part throttle surging down the road?
Considering that most all failures, even vacuum leaks, default to rich condition and because I know you already replaced FI points and most everything else, I think we are still looking at a MPS setting that your engine is not happy with.

Scott, i was playing around with that last night, - right now the ECU idle adjustment is set only one click clockwise, it is best there, - if i go 2 clicks more rich(clockwise) it gets worse. - so either the mps is way off or the ECU is off(my interpretation- do you think?

by the way you have played with these- someone has some unmolested 049 MPS for sale on this board. i believe that is set for 1.7, can those be recalibrated for a 2.0 ? i have not been able to find a reasonable 043 MPS(75-2.0)

Phil

Hey Phil, this is curious as that would indicate a rich condition, but you are saying it surges at idle still?
Yes that MPS can be recalibrated.

Update--

It was surging and very low idle with the a.a.r.plugged because it is not closing, scott suggested I adjust the mps to richen up the idle. The plug was removed by previous owner, . One turn out and the idle is smooth at 1150(according to the gauge - )

I will leave this way I think. Ran great! 3400 rpm no hesitation.