I did a simplified sequential and had to remove all the stuff but i doubt that could be causing it... i believe something similar happened to me last time and it was something regarding the throttle body gasket... I am at a lost any suggestions?

Alex

 

You probably blocked off the ISC. You need that to bump the idle up.

 

How do I unblock it...

 

It wasent happenning before I removed the Warm up system, which i also cut the wires off to it and cut the wires coming out of the yellow and other plus from the vacuum lines ( I went simplified sequential) I tried two different idle speed controls and no change. I have a power fc installed I tried raising the fuel to 100% at 1000 rpms and still no change. could it be a leak somewhere? what powers up the idle when the a/c is on... it doesnt happen with the lights on or radio only with a/c butoom even at low

 

Did you check your idle speed settings on the PFC?

 

yes, they were already preset i got it tuned by steven kan.

So this is where I am at so far

I adjusted /checked the clutch switch. No change.

I checked the resistance coming from the idle speed control it was 1.2 whether the AC was off or on

The PFC shows a hike in rpms as soon as i press the a/c button from 800 where my idle is to a little over a thouand but its only for a blink of an eye then it crap shoots really quickly to 600-650 or so and keeps itself there not completly dying but about to.

The wideband shows 12.5 at idle with A/C off and it drops to 11.2 when A/C is on at any level

I checked all the check valves and they are all pointing the right way.

I adjusted the idle with the air bleed valve, moved the dashpot, adjusted the top screw and no difference...

TPS is set per PFC to .40 value1 and .95 value 2 - Runs perfect without AC button on and good idle.

I think either something is blocking the air from getting to whatever lets more air in to keep the idle high. Which vacuum line should i check to see if something is getting blocked off? Even though I went simplified sequential I did keep the double throttle and i blocked off the following:

A. I blocked off the two long nipples coming out of the manifold facing the tranny.
B. I got JDM upper and lower so NO EMMISIONS.
C. I cut the connectors off for the 3 other solenoids i wasent using and i also cut off the plug for the AWS.

I have the MAP connected the right way and again everything was working fine prior to the simplified sequential.

 

Try setting you idle speeds higher than the norm, You may need 1000 rpm for no EL or AC. I had to play with the settings on a customers car, before I got it to it's sweet spot.

 

interesting i have the same issue,

 

I will post my setting I found to work well for me, it may or may not help but something to work off of I think .

 

But it was idling fine before I like my idle at 800

 

Check to make sure that you didn't bend any of your AC pipes. I speak from experience that when an AC pipe is bent/crimped the car idles like **** with the AC on.

 

Do you mean voltage? Resistance of the IAC solenoid should be 10.7 - 12.3 ohms (ours is 12.1 ohms). Resistance does not change with switch settings.

Voltage (when connected) should rise when A/C compressor is turning. This info comes from the Electrical Load Unit thru the stock PCME (don't know about how the PFC works) to the IAC valve.

If you are including the IAC solenoid valve in that statement, there is the problem.

 

Update: I set the power fc to 500 rpms and backed off all the idle inputs and started the process of initiating one by one to see if there was any change and nothing...

Sorry let me specify.
The resistance on the iac is 11.9 but the wire that attaches to it read 1.2 voltage... whether the ac was on or off.

Alex


OMG!&@^#%^&@ I did bent one of the lines... ill try to open it up and see if that could be what is causing it.

Thanks!

Alex

 

okay so its not the a/c lines being bent. I did notice that the plug coming out of the a/c is doing something weird or maybe its always been like that... Anyways when i disconnect it and turn the a/c on the idle jumps to 1000 and stays there but no cold air comes out. when i plug it in the idle drops but i have cold air...Pic below!

 

Update: I changed the MAP - no change. I unplugged the 02 sensor no change. I cleaned the ground by the oil pan - no change.
I CHECKED THE VACUUM lines i can see going to the chambers and they are right. - I have a feeling it might be something blockign the air from the throttle body to keep the rpms high... WHAt keeps the rpms high while the ac button is on?

Alex

 

Back the air bleed out on the bottom of the throttle body under the intake elbow, this feeds the air to the ISC. If you have it screwed in all the way the ISC has no air. The ISC is a controlled vacuum leak to raise the idle.

 

its unscrewed 2.5 turns... but ill back it up all the way and see...

I backed it up 10 turns.... now my rpms are at 850 no ac and 950 with a/c on.... i will keep adjusting and see I believe this is the answer for over a decade of a/c stalls....

 

If you are having to back it out that far I would say the hole is gummed up. 1.5 turns usually does the trick. Regardless it sounds like the problem has been identified.

 

And make sure 02 feedback is turned OFF in the PFC settings

 

The picture you have circled is the wire for the ac clutch activation. So unplugging that disengages the clutch = no compression from the ac unit.

 

I cleaned the hole with alcohol and throttle cleaner and used a wire to try to get any risidual from it but nothing... if the screw is all the way in i counted 10 full circles could somethign else be causing the screw to be backed out soo far?

Alex

 

Wait, is the ISC valve blocked off or not? Take a picture of the back of your throttlebody and UIM area.

 

The Electrical Load Unit will sense when the AC compressor is turning and "tell" the PCME to increase the duty cycle of the voltage to the IAC valve. With a PFC, I have no idea.

 

the Idle speed control valve is a constant frequency, variable duty cycle valve. It cycles 244 times a second (244hz) according to the Service Highlights document from Mazda. The ratio of ON to OFF time, the duty cycle, controls the flow through the valve. It's a typical design of that era and plenty of piston engines used it.

The PFC has a solenoid driver for it just like the stock ECU or any other standalone. It does not vary the voltage (like 0-12V linear output). It only switches the ground on or off.

 

that makes no change...


I replaced it with 3 different ones... and to no avail... The ISC's i tested were not blocked off and neither is my throttle body

I see thanx...