Hey guys it's my first time posting here so im new to this and i'm also new to my 1990 ha3 honda acty rwd, which i just bought about a month ago. It drives fine and ac blows cold, it's just when i turn the ac on the idle drops like 2000 rpm so i don't think the ac idle is working. To compensate for this, i adjusted the idle when the ac was running with the head lights on (because those drop the rpm a little also) and then raised the idle till it wasn't dying. It works fine it's just when the ac compressor turns off the idle goes really high. i also tried messing with the ac idle screw and didn't see a difference. i've replaced spark plugs, and seafoamed the carb and sanded the distributor cap and rotor metal parts (i know i need new ones soon) and it seems to run fine and it's pretty powerful and starts up really fast with out any throttle most of the time. Just the idle thing i want to sort out. I can post pics also if you guys need more info. thanks for any help
oh i also checked the 2 solenoids by disconnecting them when the car was in accessory and reconnecting them and i can here them clicking/moving. i know this isn't the best way to test but just wanted to put this out there.
read this thread https://minitrucktalk.com/threads/ha2-acty-high-idle.20660/ also check the fuses. Fuse Box: Is mounted on the firewall under the dash to the left of the steering wheel. Details https://robrobinette.com/Honda_ACTY.htm
yeah i've read that one and it doesn't seem to be the issue. i read abt every forum on here abt the acty relating to my issue and read the whole robinette book. I have yet to see anyone addressing the ac idle. i've seen u posted that your idle seems to go up when turning on ac (accessory idle) but mine doesn't seem to work as the idle drops when the ac turns on. the truck also sometimes when i turn it off seems to fire a few more times and stumbles until it stops. thanks for the reply btw
on any car system the engine idle RPM should go automatically up when the alternator does not produce enough power when high power consumers like AC, headlights , defroster etc are switched on. Did you check the alternator belt for slipping? Did you check the alternator output already? Because if the engine control unit does not get the required power, it might play a bit crazy also. For example on my 1988 BMW V12 engine: Low voltage will set engine control in limp home mode if voltage drops below 11V for more than 90sec. Low voltage will also cause problems with the heater, AC, memory for seats/steering, and transmission will go into limp mode. here some info on alternator function and testing https://aa1car.com/library/charging_checks.htm quote: CHARGING SYSTEM DIAGNOSIS: Always check the performance of the charging system when replacing or recharging a battery. A charging system that is working properly should produce a charging voltage of somewhere around 14 volts at idle (13.8 to 14.3 typically) with the lights and accessories off (always refer to the vehicle manufacturer specifications). When the engine is first started, the charging voltage should rise quickly to about two volts above base battery voltage, then taper off, leveling out at the specified voltage. The exact charging voltage will vary according to the battery's state of charge, the load on the electrical system and temperature. The lower the temperature the higher the charging voltage, and the higher the temperature the lower the charging voltage. The normal charging voltage on a typical application might be 13.8 to 14.3 volts at 77 degrees F. But at -20 degrees F, the charging voltage might be 14.9 to 15.3 volts. For a hot engine on a hot day, the normal charging voltage might drop to 13.5 to 14.0 volts. alternator: Charging output can also be checked with an adjustable carbon pile voltmeter and ammeter. The carbon pile is attached to the battery and adjusted to obtain maximum output while the engine is running at 2,000 rpm. Charging amperage is another number that can reveal the condition of the alternator. With the engine idling and no load on the charging system (lights and all accessories off, and battery fully charged), the amperage output should be relatively low (typically less than 10 amps). With the headlights and heater blower fan on and the engine running at 2,000 rpm, the output should jump to a higher reading, typically 25 to 30 amps or more. https://aa1car.com/library/2004/ic120434.htm Maybe someone with a Acty repair manual can chime in with more details.
here something from Bosch, same what I said above, if electric load is switched on = idle speed increases: When an electrical load, such as headlights or heater fan etc are switched on, the idle speed would tend to drop. The idle ECU will sense the load and rotate the Idle Speed Control Valve ISCV to increase the air flow through the valve and thus increase the idle speed. When the load is removed, the ECU will pulse the valve so that the air flow is reduced. Normal idle speed should be maintained under all cold and hot operating conditions. If the ISCV fails it will fail in a fail save position with the aperture almost closed. This will provide a basic idle speed. http://www.opel-scanner.com/files/DME_1.1_1.3.pdf Bosch Motronic was and is widely used by many car makers, but the systems of others are similar.
I read over whats been writen here. hoping this will help. there is a box of control stuff for the AC mounted on the frame just forward of engine, follow the vaccum lines to find it. I took mine out to study it and didn't but it back in. I am not using my AC, removed all of it, saving it. when you turn on the AC a vaccum switch send vaccum to a diaphram #17 on the side of the carburator, to pull up the idle. As for your "run on" when turning off engine. It may be that your idle is set so high, it is running from the main jet. when you turn off the key, power is turned off to the idle fuel solenoid #11 . this is one of the valves, veryone, has been replacing, when they are have carb promblems. I gave up long time ago trying to get people to understand that it isn't part of their problems. when your truck is running , try disconnecting this solenoid. motor should die. it controles all the fuel to the idle jets. Use to be called "anti dieseling solenoid" from the 70s. I saw a question awhile back where the truck would run when rpm was high but die when it was let into the low range, that was this valve soleniod not working. Anyway back to your situation, see if you have Vaccum on the diaphram on the side of the carb, when you turn on the AC. Take a good look at the linkages on the side of carb, you see how it all works. Has for diagnosing the problem, if the fix isn't simple. I have the manual in Japanese, if you need some pages, Let me know. its got a lot of stuff on the AC. I can't translate. but the pictures tell a story. (Google translate helps too)
Thanks for the help man. it seems there isn't vacuum going to the diaphragms. i followed the vacuum lines and i saw a box near the center of the truck which had vacuum lines going to it and i also see a black box to the left of the battery mounted on the frame which seems to have wires running to it. i also checked and it seems the solenoid w the green wire stopped working. i was driving it today and all of a sudden it would die when i gave it throttle and i had to take the air box cover off for it to drive just enough to get home. do you know why vacuum wouldn't be going to the diaphragms?
how do i test this accessory idle iscv? it seems mine isn't kicking on as it doesn't compensate for the extra load when ac is turned on. thanks again y'all for the help idk where else to look. ur help is like a light of hope haha
actually i looked at the attached images and i know what part u are talking about. i don't want to delete it though as i live in florida and would like my ac is there a way to diagnose it?
the black box to the left of the battery mounted on the frame which seems to have wires running to it is probably the fusible link, 45A the solenoid with the green wire could be this https://yokohamamotors.net/product968.html google search with Honda acty idle speed control valve and more info comes up like https://minitrucktalk.com/threads/ha2-acty-high-idle.20660/ old Machinist mentions: Only the Honda's with AC or automatic transmissions had solenoids or vacuum pulls to increase the idle. https://minitrucktalk.com/threads/t...ops-idle-speed-a-lot-how-do-i-fix-this.13733/ https://minitrucktalk.com/threads/trouble-shooting-carb-wont-idle.14407/
How to test the solenoids I posted above. I recommend to buy a Honda Acty English Factory Service Manual , good investment, you need it anyway for the future. The Honda Acty repair manual mentions on page 58 carbureted idle setting: run engine up to 3000 RPM for 2 minutes and let idle remove carburetor cover and disconnect fast idle roller (re-connect after idle setting) on the carb there is a fast idle roller, fast idle lever, fast idle cam set idle at the adjustment screw MT vehicle 1000 +/- 50 RPM, 1150 +/- 50 RPM for 4ED truck UL/UR AT vehicle 950 +/-50RPM Note: AT set in D if idle does not set properly, check ignition timing if ignition timing is set properly, check Pilot screw page 59 explains AC idle up adjustment Note: only AC equipped vehicles remove cap from AC idle control diaphragm under the cap there is a adjustment screw idle speed AC engaged MT vehicle 1350 +/- 50 RPM truck, 1100 +/- 50 RPM Street, Van AT vehicle 950 +/- 50 RPM with "D" drive position Note: erratic idle can be caused by incorrect timing setting. VACUUM leaks can fail to open diaphragm.
found some more in the repair manual, re-typed from page 126: idle control unit on carbureted vehicles is behind the dash, left side of the instrument cluster, between instrument cluster and the air grills Note: improper grounding can cause failure, check pin # 3 for ground. unit check: ignition switch to on position check pin #1 for power and pin # 3 for ground note: to reset unit remove turn signal light 15A fuse for 10 seconds heater fan switch: start engine, check pin #6 (+) and pin #3 (-), failure, replace unit radiator fan switch: start engine and warm, check pin 7 (+) and pin 3 (-), fan does not engage, replace unit rear defroster equipped vehicles: start engine and warm, test defroster switch, test pin 5 (+) lighting switch and idle control unit: ignition switch to ON, check pin 4 (+) and pin 3 (-)
I tried turning the ac idle screw on the diaphragm and it doesn't do anything. it seems like it's not getting vacuum
check the vacuum lines, maybe brittle, diagrams are shown in the repair manual or click here https://minitrucktalk.com/threads/honda-acty-vacuum-diagram-1995.14400/ or the diaphragm is defective? Download these 294 pages Acty repair manual https://img1.wsimg.com/blobby/go/4c...ed Honda Acty Manual_1989-1997_Danko, Jam.pdf
[SOLVED] Thanks for all the help. i replaced the solenoid and it seems the wire connecting to the solenoid is whats broken so i hard wired it to my battery. Seems to idle great with ac and with out but i just wonder if my battery will die by having this direct connection to the battery. i also found out that i needed to back off the ac idle screw as it seemed it was to far in to work and when i u screwed it, it raised the idle.
good to hear that you found the cause, but hard wiring to the battery is not ideal, it might drain the battery. Check the original wire, maybe you can repair the broken part or replace the wire complete, or at least wire the solenoid to a wire which is only hot with ignition on.
