[Jay52395]

Hello all, I’m new to the forum, so thanks for having me! I come from a family of master techs, and performance engine builders, and previously worked for a few local dealerships, and currently do some auto mechanic work on the side. I would consider my auto mechanic knowledge/skill level intermediate at best, still learning!!

On to the A/c issue with the V.
First off I replaced the wife’s A/C compressor earlier this year due to the old one taking a dump on the V.

After installing the new compressor, we got about 5 good months out of it before this new issue formed.

The issue: at norm Op temp the clutch will cycle on, then back off about 10-15 seconds later, as if it’s low on Freon. (No codes present or stored on ECU)

So I swing by the local auto parts store, grab myself a handy dandy can of 134a, and get back home. I keep the car running so it’s nice and hot, turn the air to max with re-circ on. And I can’t find my manifold gauges...... soo luckily I have a low pressure feeder hose with a gauge on it (yawn). I hook the bad boy up crack the bleeder screw open barely and the needle instantly jumps to 45 PSI, and holds there. I wait for the compressor to cycle and it drops to about 39-40PSI for a split second, then right back when compressor clutch re-engages.

So next I throw a temp gauge in the vent. She blows steady 39 degrees with 97 out side ambient air temp.

With all of this said, I’m looking for anyone that might have had the same issue, what did you do? My plans are to start with finding my 134a gauges to check the high and low system psi, next the Idle sensor, because often when it’s warm and the vehicle comes to a stop, the RPMs will fall to about 550-575 and the clutch will cycle out. I’ve heard this is a common issue. Next the EVAP temp sensor? Compressor relay seems to be in working order (will still inspect for correct operation though)..

Any input would be greatly appreciated!

 

[kloker]

I highly recommend you get yourself a factory service manual. It contains a 145-page section on troubleshooting and repair of the system. Mine has already paid for itself easily. I got my copy in CD (pdf) form from, eBay, for $45. One thing it contains is instructions for how to run the built-in self-diagnostic test. Then it goes into great detail on everything, including how to diagnose every relay, sensor, and component of the system. Keep us posted on how it goes.

 

[Jay52395]

I highly recommend you get yourself a factory service manual. It contains a 145-page section on troubleshooting and repair of the system. Mine has already paid for itself easily. I got my copy in CD (pdf) form from, eBay, for $45. One thing it contains is instructions for how to run the built-in self-diagnostic test. Then it goes into great detail on everything, including how to diagnose every relay, sensor, and component of the system. Keep us posted on how it goes.

Do you possibly have a link to that? If not nbd I’ll find it.

Thank you!

 

[Dave J]

that low side is a little high,I would check the fans make sure they work,overcharge can do that also,air in the system could do that also , the high side pressure will tell more,I was just looking at specs on an 07 and 100F degrees outside and 80% humidity 45psi would be in spec for the low side,also it was put under a vacuum forat least 15 mins before the oil and 1.1 lbs of r134a right, -29 vacuum for 15 minutes minimum 30 mins is better is a must whenever the system is opened and the receiver dryer or condenser with dryer should be replaced when ever the system is opened,also if you hold the RPM's at 1500 does it still cycle like that because a low idle could cause that if it gets too low,may need a throttle body cleaning and idle relearn ,here's some idle info 575 with loads on is too low,PDF below

 

[Jay52395]

that low side is a little high,I would check the fans make sure they work,overcharge can do that also,air in the system could do that also , the high side pressure will tell more,I was just looking at specs on an 07 and 100F degrees outside and 80% humidity 45psi would be in spec for the low side,also it was put under a vacuum forat least 15 mins before the oil and 1.1 lbs of r134a right, -29 vacuum for 15 minutes minimum 30 mins is better is a must whenever the system is opened and the receiver dryer or condenser with dryer should be replaced when ever the system is opened,also if you hold the RPM's at 1500 does it still cycle like that because a low idle could cause that if it gets too low,may need a throttle body cleaning and idle relearn ,here's some idle info 575 with loads on is too low,PDF below

Dave thank you for the information I will look into that tomorrow, I just ordered my new gauges today and should be here Monday morning.

- I would lean towards the idle air, but as you’ve asked: if I bring the vehicle above 1500 rpms; the symptoms still exist. I timed it today at 14 sec intervals while doing 55mph on the highway. Never looses cold air though so that’s a plus I guess lol.

At an idle the fans come in with the clutch engagement every time it cycles. I’m probably going to do the cleaning anyway as it’s currently sitting around 142k miles, and hasn’t had it serviced to my knowledge.

As far as the pressure, i was thinking it was pretty close (slightly high) as I’m in middle Georgia, and the humidity this time of year rarely drops below 95%, and temps of 95-100 lol!!

 

[Jay52395]

Dave thank you for the information I will look into that tomorrow, I just ordered my new gauges today and should be here Monday morning.

- I would lean towards the idle air, but as you’ve asked: if I bring the vehicle above 1500 rpms; the symptoms still exist. I timed it today at 14 sec intervals while doing 55mph on the highway. Never looses cold air though so that’s a plus I guess lol.

At an idle the fans come in with the clutch engagement every time it cycles. I’m probably going to do the cleaning anyway as it’s currently sitting around 142k miles, and hasn’t had it serviced to my knowledge.

As far as the pressure, i was thinking it was pretty close (slightly high) as I’m in middle Georgia, and the humidity this time of year rarely drops below 95%, and temps of 95-100 lol!!

Also a side note: I noticed from the PDF that your using identifix, how do you like it compared to all data? How’s the pricing work? Ive been out of the dealership service world for about 6 years know so I’m trying to figure out how well identifix is for automotive work on the side/hobby work.

Thanks for all of the information. This forum is definitely a lot different from others I’m apart of. People actually seem like they enjoy sharing knowledge and helping people! It’s refreshing!

 

[Dave J]

i like the identifix ,in the past 16 years I have used alldata and mitchell and Identifix seems to be better the wiring diagrams have been correct so far for 2 years the other 2 had a lot of bad info on wiring colors,and identifix has technician input on codes and symptoms,example on a ford transit with a vent solenoid code I found no power to it and in identifix they show that about 3 foot up the harness a common spot for the wire to break but the insulation is still intact sure enough thats where the problem was so it does help speed up diagnosing a problem,you know every vehicle has some kind of common problem,so it helps a lot because I work on all makes all models.guys at the dealer can diagnose problems when its still on the tow truck LOL,I never checked the cost I have it through my work,sounds like it may be overcharged a little the high pressure cutoff specs is 455psi but above 215 cycles the clutch,here's PDF below,2005 and newer they did away with an idle air valve so the throttle body does all the idle speed work except for the cold air bypass valve that lets some air past below 160f coolant temp. i think

 

[Jay52395]

i like the identifix ,in the past 16 years I have used alldata and mitchell and Identifix seems to be better the wiring diagrams have been correct so far for 2 years the other 2 had a lot of bad info on wiring colors,and identifix has technician input on codes and symptoms,example on a ford transit with a vent solenoid code I found no power to it and in identifix they show that about 3 foot up the harness a common spot for the wire to break but the insulation is still intact sure enough thats where the problem was so it does help speed up diagnosing a problem,you know every vehicle has some kind of common problem,so it helps a lot because I work on all makes all models.guys at the dealer can diagnose problems when its still on the tow truck LOL,I never checked the cost I have it through my work,sounds like it may be overcharged a little the high pressure cutoff specs is 455psi but above 215 cycles the clutch,here's PDF below,2005 and newer they did away with an idle air valve so the throttle body does all the idle speed work except for the cold air bypass valve that lets some air past below 160f coolant temp. i think

Thanks for all of the information! It helps a lot, my new gauges should be here any minute now. I’ll get on it as soon as they get here and update the thread!

 

[Jay52395]

Alright alright! Finally some answers.... some answers.. not all answers.. lol

For all those that gave me information, and would like follow up:

First off thank you for the help!

Secondly: my gauges finally came in, so I took the car for a drive, got it nice and hot. Hooked up my new gauges and the system was low. At 88 ambient air temp with 83% humidity; it was sitting at 39psi low and 223psi high. After adding some Freon I got the high up to 275, and low wouldn’t go over 45psi without overcharging the high side. ( all within spec according to Honda) however the low pressure is at the lower end of the minimums for the listed ambient temp/humidity.

Potential causes of this? Clogged expansion valve? Still air in system? Idk.