Question for auto mechanics

[rage]

i have a 92 honda civic LX and am having trouble with the AC. When i turn on the AC it works fine. However, when i stop at a stop sign or red light and try to move again it seems like no fuel is getting to the engine. The only way i have found to get moving again is to shut the AC off and restart the car. After that it runs fine, until I turn the AC back on. Being summer and all and living in the south it really sucks driving without AC. Any ideas on what can be causing this?

 

[NOSLEEP]

Re: Question for auto mechanics

It sounds like the Idle sensor may have gone<br />bad on you, could also be a mass air flow sensor.<br />Maybe there is an adjustment to bring up the idle<br />so the engine doesnt stall when the a/c is turned<br />on.

 

[Spidybot]

Re: Question for auto mechanics

Right - a number of setups have been used. Some AC's interacts with other devices like setting the fan on, adding idle etc.<br /><br />The rpm reported to the ECU should make the ECU compensate for the AC load - provided all works as supposed to. Hate to say this, but a call to dealer to hear his advice is needed (not saying he is gonna get the job ).

 

[mellowyellow]

Re: Question for auto mechanics

think UU nailed it... is the electric fan coming<br />on?

 

[Spidybot]

Re: Question for auto mechanics

Another thought: If your ECU is 'adaptive' (learns it's working conditions and manages the engine accordingly) it may simply need a reset as <br />done by workshops during normal service.<br /><br />Instead of paying them to this you just disconnect the battery negative and count to 30. Then refit.<br /><br />All tasks from here has a price, so better know what the pro's suggest to avoid waste of $$'s.<br />Before going on from there I'd call the dealer.<br /><br />Does the ECU adjust idle if it's slowed by other means (cold start)? The idle is maintained by a small stepper motor that opoens a valve. Cleaning thes valve/seating could do the trick (cleaning by special purpose spray can work although a little dismantling makes it easier and better).

 

[SeaMasterZ@aol.com]

Re: Question for auto mechanics

if all else fails, could always bump the idle for the summer months, 150 more RPMS should do it<br /><br />cheap easy effective ... my favorite adjectives!<br /><br />

 

[rage]

Re: Question for auto mechanics

Thanks for the help fellas but i have a question. 1: How would the idle adjustment help when it idles fine. It stalls when i try to go again, like it is not getting enough fuel to drive. But idle is fine, it will idle forever, for now anyways. 2: I found a guy that said I could his scanner to see whats wrong for a small fee. Do you think that would help to find the problem? Thanks fellas

 

[Spidybot]

Re: Question for auto mechanics

We're pretty much guessing here.. If your idle is ok while idling but cuts out one second before the running system should take over, the fault still sits in the the idle. <br /><br />In your ECU those areas merge - you have running conditions where part idle and part running conditioins makes mix the system. A proper faultfinding routine will point out some sensor or sending unit that does not comply. <br /><br />If your friends 'scanner' is compatible with your system and the fella knows how to read it, it may very well point out the faulty device.

 

[SlowlySinking]

Re: Question for auto mechanics

Hi Rage, scanning the computers's memory for trouble codes is always a good idea. The idle speed is computer controlled, as you put more load on the engine as in turning the AC on it automatically adjusts the idle speed to compensate. If you have a tach watch the RPM's as you turn on the AC, it should stay steady, if it drops and stalls then you can see your problem. One point on trouble codes, when you get any or more than one be careful to analyse before replacing sensors, could be something else and they can interact with each other. My wife's car produced 7 codes which indicated that both oxygen sensors were out of range and not switching, the mass air flow meter was bad, and other sensors were bad, about $600 dollars worth. The probability of this is about the same as winning the lottery. A check of the schematic indicated a common ground connection, it was loose and a quick cleaning and tightening eliminated all the codes.

 

[clanton]

Re: Question for auto mechanics

Some of the Hondas of year that had a corrosion problem with the connection to intank fuel pump, sometimes the fix was to just clean the termial. The outside termial close to the tank. This is a longshot, but worth a check. Some of them also had a switch that turned off the AC during full throttle, then back on as soon as you let off the throttle, may be a problem in this area. Check Alternator, may not be enough power to run AC and pump, when engine is loaded.

 

[rage]

Re: Question for auto mechanics

I think i understand what you're saying. Friend is bringing scanner and we will go from there. Thanks for the help fellas. I hate trying to work on these new cars

 

[SpinnerBait_Nut]

Re: Question for auto mechanics

Rage, if I am reading this post right, you say it will idle fine without the a/c on, but as soon as you turn it on, the motor boggs down or dies.<br /><br />Do you hear any strange noises when this happens, like a belt squealing?<br /><br />Will it do this in neutral also? Or just when you put it in gear?<br /><br />If this is correct, check the a/c pulley to make sure it is not trying to seize up on you.<br /><br />One dragging on them small engines will draw it down to where it will not run as in stopping engine.<br /><br />Turn the key to the on position and turn a/c on, then take belt off a/c unit and spin the pulley to see if it is free.<br /><br />It will have a little tension to it, but you should still be able to spin it by hand some.

 

[mellowyellow]

Re: Question for auto mechanics

clanton reminded me of something on my old honda.<br />the a/c would shut off temp. when motor needed<br />extra HP....maybe check that switch/sensor as he<br />reccomends?<br />good luck,<br />M.Y.

 

[Skinnywater]

Re: Question for auto mechanics

I'd stick closer to basics on this one, rather then ECM's and sensors. <br />I'd be looking real hard at battery cable, fuse and relay connections. Check the dedicated engine ground cable. <br />The blower motor and condensor fans can tax a weak electrical system pretty hard causing low voltage, spikes and resistance <br />If memory serves me, most Asian fuel pump relays are looking for an excited alternator/regulator.<br /><br />Check all engine connections for tightness and integrity.<br /><br />BTW, a '92 will still be OBD1, very limited memory and no adaptations.