Need some help


ALEX-CY

Active Member
Joined
Mar 17, 2009
Messages
790
hi. when I switch on my a/c on and the engine is gold the idle revs is ok. after the engine start to get hot I have very low revs(500-400) and the engine is start to shake. when the engine is on normal temperate everything is ok. I have an ek with ek9(1999) loom and b18cr 96spec engine and oem ecu(dc2)
I already full service the engine, check TPS, replace idle valve, check timing
I also replace the a/c compressor(old has oil leaking) replace the a/c drier and service the a/c system.
any ideas?
thanks.
 
You need to do idle Relearn procedure pal .
1,Get engine up to temperature fan on&off
2, unplug iacv and purge control valve .
3. Adjust rpm to 500 rpm from idle screw.
4. Turn car off and pull the battery fuse
Let car cool/cold
5. Reconnect all plugs and fuse .
6.start car leave for 5 minutes with everything off !
Then put lights on for few minutes then ac and leave for 5 minutes,
7 . turn car off keys out .
Then take for a drive and let's us know how that went .
 
I adjust the idle like the manual write(almost like you set)
I have no problem with my car at all. the idle and everything else is working perfect. I have this problem only when I use the a/c.
it fells like the engine is weak when is gold and it cant handle the extra power from the a/c
 
Your altanator might be at fault or battery ,
Check your earths also .
 
Your ac pulley wheel spins freely ?
Strange one alright
 
yes. I have the same problem with both a/c compressor(old and new one). I don't think the problem is the a/c..
 
since you mentioned that you replaced the ac compressor, this "may" be worth checking.
1. In your old compressor, one thing that can cause your idle to go down is that your ac system is on high pressure.
2. In your new compressor, one thing that can cause your idle to go down is over filling the ac system with freon..i forgot how much but it's in the manual. Basically, the compressor is taking much more power than usual due to more freon to pump. in my opinion, it's worth a try to check these since you'll just attach those pressure gauges and fittings in an ac shop or something..
 
since you mentioned that you replaced the ac compressor, this "may" be worth checking.
1. In your old compressor, one thing that can cause your idle to go down is that your ac system is on high pressure.
2. In your new compressor, one thing that can cause your idle to go down is over filling the ac system with freon..i forgot how much but it's in the manual. Basically, the compressor is taking much more power than usual due to more freon to pump. in my opinion, it's worth a try to check these since you'll just attach those pressure gauges and fittings in an ac shop or something..
thanks. I have the same problem with the old and new compressor. The Freon and the a/c service is made by professional . all the pressures are ok. don't forget when the car is on normal temperate is working ok. have this problem just before the car take the normal temperate.
 
I replace the dizzy and spark wires but the still the same. when the engine is cold very low idle with the a/c on. after the engine gets hot is better and better until the normal operation tem. is everything perfect.
with a/c off no problem at all
any ideas?
 
Do you have a way of checking your voltage, your problem my be you ek9 loom and each component not talking to each other.

What car is the engine in?

I had a similar problem with my ek9 after an engine swap, the ek9 electronic load detector (eld) is in the fuse box and on usdm and edm civics it is in the alternator. Just for those who don't know the eld provides extra power when other systems drain big power etc lights, power windows, air con

I noticed my car was only at 12v and not the 14.2v it should be and when I had lights, wipers and fans on it was at 9v and eventually started to loose charge. All the electrical parts on your engine need the full 14.2v

My problem was I had a usdm ecu a edm engine and a jdm fuse box, alternator and loom so all these didn't speak to each other, i tried new alternators and no fix untill I replaced the loom and alternator and it's been at full voltage since.

Check your voltage first as new alternators and looms aren't cheap
 
Do you have a way of checking your voltage, your problem my be you ek9 loom and each component not talking to each other.

What car is the engine in?

I had a similar problem with my ek9 after an engine swap, the ek9 electronic load detector (eld) is in the fuse box and on usdm and edm civics it is in the alternator. Just for those who don't know the eld provides extra power when other systems drain big power etc lights, power windows, air con

I noticed my car was only at 12v and not the 14.2v it should be and when I had lights, wipers and fans on it was at 9v and eventually started to loose charge. All the electrical parts on your engine need the full 14.2v

My problem was I had a usdm ecu a edm engine and a jdm fuse box, alternator and loom so all these didn't speak to each other, i tried new alternators and no fix untill I replaced the loom and alternator and it's been at full voltage since.

Check your voltage first as new alternators and looms aren't cheap

Agreed- I recently had goofy voltage issues, headlights would dim below 4,000 RPM's, and so forth- pulled an ELD out of an Integra and installed in my Hatch, and all problems were solved. very strange since the only thing I replaced was the ELD strip, which is just a piece of metal connecting two contacts. But it worked...
 
thanks for the replies. I check all the electrics on my car and they work perfect. I have led and is working good. I have 13,8v to 14,1v all the time. when the car is on normal temperate the idle with a/c on is ok.
next thing I will check is the oxygen sensor. what do you think? Maybe when is not very hot is not working good.
 
Would doubt the O2 sensor, but it is possible.
Normally when the A/C is turned on, it sends a signal to the ECU-at that point the ECU ups the % of the Idle Control Valve to increase the incoming air and slightly changes the ignition timing to compensate for the extra load. The works just like the power steering High Pressure Switch- when pressure in the high side hose reaches a high enough point, the contacts close, sending voltage to the ECU, and thus it increases the RPM's to compensate. It sounds like either your ECU isn't getting this signal input, its not reacting to it, or the out puts aren't responding.
If you disconnect both your cooling fans and the one wire connector at the A/C compressor ( so the compressor doesnt engage ) after the car is warmed up, start the car and press the A/C button on your dash, you should notice the RPM's increase a bit. If it doesnt the the ECU isnt doing its job ( weither its an input, or an output issue takes more testing ), but if your RPM's do increase then you know that the ECU functions are correct ( input and out put ), and there is eccessive load on the mechanical portion of the A/C system.
 
Would doubt the O2 sensor, but it is possible.
Normally when the A/C is turned on, it sends a signal to the ECU-at that point the ECU ups the % of the Idle Control Valve to increase the incoming air and slightly changes the ignition timing to compensate for the extra load. The works just like the power steering High Pressure Switch- when pressure in the high side hose reaches a high enough point, the contacts close, sending voltage to the ECU, and thus it increases the RPM's to compensate. It sounds like either your ECU isn't getting this signal input, its not reacting to it, or the out puts aren't responding.
If you disconnect both your cooling fans and the one wire connector at the A/C compressor ( so the compressor doesnt engage ) after the car is warmed up, start the car and press the A/C button on your dash, you should notice the RPM's increase a bit. If it doesnt the the ECU isnt doing its job ( weither its an input, or an output issue takes more testing ), but if your RPM's do increase then you know that the ECU functions are correct ( input and out put ), and there is eccessive load on the mechanical portion of the A/C system.
I check all i/p and o/p signals to ecu and are ok, I replace the ecu and still the same. I check the idle valve when the a/c is on and you can see that is open more(take it out from the t.b)
 
I order obd2 reader with Bluetooth and I will check all the sensors how they work until the engine gets hot. I hope it will help me
 
hi again. I notice that the revs is not very stable when the car is not moving. lets say that I press the throttle to 2000 rev you can see that is moving from 1900 to 2100. any ideas?
 
Is the engine note actually changing, ie the revs actually going from 1900 to 2100 or is it just the needle moving on its own?
 
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