d-jet a.a.r. question, 8/18/ AAR open vs closed - effect on setting timing-advance Options

[DRPHIL914]

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

[ConeDodger]

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.

[Valy]

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.

[ConeDodger]

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

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

[Tom]

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

[McMark]

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.

[cary]

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.

[r_towle]

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

[DRPHIL914]

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

[Tom]

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

[underthetire]

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

(IMG:style_emoticons/default/agree.gif)
I bench tested one with a Tek power supply, at 13.5 volts it pulled ~1.2 cold, dropped slightly after heated.

[euro911]

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.

[DRPHIL914]

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

[swl]

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.

[DRPHIL914]

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

[Tom]

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

[swl]

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

[euro911]

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).

[DRPHIL914]

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

[ConeDodger]

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.