Does the same on my car. D20. I know my idle w/o ac is in 900 range. When ac is on the car increases idle to compensate for the extra load. As for what your idle SHOULD, idk.

 

The air conditioning issue is problem an entirely different problem and isnt liked to the rough low idle. I'm going to change out the filter of my intake, and work back to the intake manifold cleaning the sensors as I go before i replace anything. The previous owner lived down a massive dusty road, so im hoping i find a clean intake, and not caked up..

 

After work I fired the car up (Cold). Idled decent at 1000 rpm, 1-10 scale 10 being car died, i give it a 2 in roughness. Before the car warmed up, i tested the AC buttom and listened for the compressor to engage. It did, and didnt impact the idle. I than turned it back off. As the car warmed up and the temp gauge showed in the middle, the idle dropped down to 750/800 with a rougher idle. I'd say 5 out of 10. I let it sit and idle for another 5 minutes and nothing changed. I than moved to test out the AC once again. This time it surged up to 1400 rpm, and than came down fast, killing the car. Odd that while cold and high idling at 1000rpm it has no impact, but at warm idle its enough to kill car. Ill work on uploading some vids.

Also while at low idle, the back-lit odometer thats illuminated in green can be seen pulsing to the naked eye.. hmmm

 

https://www.youtube.com/watch?v=f6YeQS8cydo&list=UUkT29rfgUcSLfE781BEes0w

Audio of the exhaust (what i'd call 5/10). sounds more burley than in real life.. haha

 

Low rough idle and pulsing lights sounds like your alternator might be going out, or the wiring pigtail coming off of it is loose. The a/c compressor and fan kicking on is a major drain on the electrical system and a weak alternator can't compensate, so that would account for the stalling. I have noticed the alternator is a weak point on these cars.

 

Cleaning the battery grounds. Super corroded. At one point someone swapped oem battery terminal connectors and did an absolute horrible job. Going to buy new now and test again.

 

Moved to General Tech Chat

Welcome to FF!

 

update...

Ok, first thing i did was replace some horrible looking battery terminal connectors the previous owner did. Checked to make sure air filter was clear and clean. Pulled intake tube off and checked for debris, checked throttle body for wear or buildup, appeared clean and ok. removed TPS and checked for range of motion and spring function. Measured the resistance from A to common, and B to common and each were the same. checked resistance over a range when turning with screwdriver and did output different values of resistance (still cant verify that its good although not throwing engine light). when i unplug it entirely engine light comes on (just a test). After 15 minutes of idling, and the temp gauge in the middle of the range, never ONCE did the cooling fans turn on.
I found some type of flowmaster style exhaust welded up (horrible welding job with leaks, taking it in to get the exhaust changed back to OEM). Another thing was i smelled A lot of gas when my head was over the passenger side engine compartment above the fuel rail. Is that normal, or is it running really rich??

Also cleaned mass airflow sensor with electronic spray, it was pretty clean to the naked eye, but sprayed it down anyways, and inspected that it was clean.

The previous owner also said he changed out the PCV valve and the brittle hose to the new factory hose if that makes sense to anyone..

 

Might have to search Vac. hoses for problems, PCV is the most common one so recheck that first.

 

update #2

didn't get to the smoke test yet. I will be doing that tomorrow. I did however spray the leaving heck out of the engine with WD-40 looking for leaks, than moved to a small propane bottle and hose probing looking, than moved on to a full size propane bottle and weed burner blasting propane in the entire rear engine bay and no throttle response.. When i do the smoke test where is the best place to inject the smoke, straight in the intake where the rubber hose from valve cover goes into?

After 30 minutes of idling, never did the fans come on, gauge showed ok, but i looked into it anyways. Found Fan 2 relay fried, and plastic was melted. Fuses both looked ok. I later found online that someone else had the same problem found here:

http://www.sparkys-answers.com/2009/10/2003-ford-focus-runs-hot-cooling-fans.html

I also have to check the fan resistor which in his case fried also (didn't check yet). Ill check tomorrow and order the parts up.

Since the gauge did show ok (not overheating), should i even believe the gauge, or should the coolant sensor be checked also? I am really surprised it didn't overheat at all.

R9 Cooling fan relay (2.0 engine only)
R10 Cooling fan relay (2.0 engine only)

More fun to come..

 

They don't usually warm up too bad at idle, has to get fairly warm before fans kick in.

 

Do you think that this has any relation to my idle problem? After this is fixed I'm bringing the car to autozone to have the battery and alternator load tested also so I can Atleast rule that out of the issues.

I may pick up a nicer scanner to see what's going also.

 

Maybe something like..

Saw a guy on YouTube use this seemed like it worked alright. Any other suggestions are welcomed.

 

5 pin relay is low fan, 4 pin is high fan, both fans work together as one either high or low.

 

Ok. Per my picture the burned up one I have is the low speed relay than. I'll check the fan resistor an pigtail tomorrow to see what condition it's in. Thanks for the help.

 

Incase someone else needs this info I'll post it. Going to check out the plug and harness now.

 

Any chance to repair the exhaust system if you like the note and not rusted?

 

Confirmed that it does need the engine system cooling resistor and pigtail plug. Both are shot.

Started up without relays installed, resistor, and cut off bad pigtail. did not impact idle. Popped the passenger side cap off the "hydraulic mount" pressed my finger on top, and it was squishy and could feel fluid. Is this suppose to be rock hard with fluid or semi saggy but fluid filled?

I think for now, ill closely examine the exhaust that's on there and see if its capable of being patched up. if its just a couple holes, no big deal. If its extensive ill be money ahead to go with new. Local shop charges about $100 with labor.

Next move is rent a OBD2 scanner from autozone and check out what the computer sees. may give me a clue for whats next..

 

Autozone part number for relays:

Low speed: 16003 $34.99
http://www.autozone.com/autozone/pa...Cooling-Fan-Motor/2003-Ford-Focus/_/N-jk8uuZ9cj89?itemIdentifier=518265_0_1132_

High speed: 19273 $14.99
http://www.autozone.com/autozone/pa...Cooling-Fan-Motor/2003-Ford-Focus/_/N-jk8uuZ9cj89?itemIdentifier=12861_0_11503_

engine cooling Fan resistor and harness plug from ebay (not autozone), $39.99

edit..
Should have looked a little closer, autozone is saying both of those relays are 5 pin relays..?? why was mine a 4 pin and 5 pin?

 

Mount should just be fluid filled, "semi saggy" sounds still OK - rock hard would be weird.

 

Ok good. I havent checked the other two mounts yet. Going to need to pull it in for that. In the holding pattern until my parts show up. Called autozone to confirm i can rent their nice scanner. Hoping that will expose something else.

 

Talked with previous owner. He replaces the idle air control valve . Didn't verify it's good off the shelf, just assuming. He didn't replace the TPS though. Well use the scanner to see if it's responding and reporting.

 

Replaced both relays, replaced the engine coolant resistor unit. Seemed to be doing a bit better (maybe in my head). Pulled negative cable, let sit for 10 minutes. Than took on a drive so engine could learn (5miles). Seems to be doing much better, honestly I need the repair manual to know I did it correct. When the previous owners replaced all the sensors they never reset ecu which I was thinking may have been the issue. It does seem better, although the air conditioner "on" will still kill the car and lower the rpm significantly when turned on even when my foot is on gas in neutral. Will hookup AC pressure gauge and see what's going on.

 

Hard to take off the AC belt? Maybe I should try and spin it by hand and see if is seized up?

 

Sure, that would be a good first check. (Center of A/C clutch assy)

With just one serpentine belt, removal isn't the easiest.