Ford Mustang Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
So, we have a 1993 LX that has just started giving us idling problems. The idle is super-low, almost to the point of killing the engine. When in drive and accelerating it is fine, but in reverse and park (or when stopped), it barely keeps going.

I did a self-diagnostic test and got codes 334 and 411. I've never dealt with EVP/EGR issues before, so any help would be greatly appreciated. When the car is off and I'm running the test, it only gives me 334. When started, it gives both 334 and 411.

From everything I've read, 411 is usually for a high idle -- but this is not the case here. I'd take it to a mechanic with the codes, but we're flat broke, so PLEASE HELP!

-Note- We recently had the timing belt replaced, but haven't had any issues in the 2 months since (until now).
 

·
Registered
Joined
·
335 Posts
Don't have a shop manual in front of me but if I recall the 334 is a voltage over expected code meaning the egr valve isn't closing. If the egr valve is sticking open at idle it could give you a low idle.

If you're capable of taking the egr valve off, try to do so and clean the carbon from inside. If you're not comfortable taking it off try to lightly tap on it while the engine is running.

Afterward you may need to clear the KAM (keep alive memory) by disconnecting the battery and leaving the headlamps on for 10 mins. I prefer to do this after the engine is at operating temperature. This will also clear the code.

Start it and allow it to idle for a few minutes in each gear. Let us know :)
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
Still Nothing... :(

I've cleaned the EGR valve out (with carb cleaner) and checked the EVP Sensor - Both look like new parts installed in the past few years. I reset the KAM and let the car idle in each gear and ran another test. Same codes.

When the car is running the diagnostic test (while on) it seems to run much, much smoother and idles between 1K and 1500. Once the test is over, the idle falls back down around 750 and struggles to stay alive (in all gears -- Reverse is the worst). It sounds like it's missing until I reach 2K RPM -- then it smooths out.

I also put a dollar bill up to the exhaust, and it's definitely missing, as it sucked the dollar back in continuously. Checked the plugs and wires, and one of the metal connectors in the wire stuck to the plug and I crimped it too much taking it off, so now I'm down a spark plug, but the car seems to run about the same. The plugs were clean though.

I'm so confused -- I feel more lost now than when I started trying to fix the damm thing.
 

·
Registered
Joined
·
30 Posts
Not sure if this will work for you, but i was having a really bad idle myself. I would start it and right after starting it would drop to 500rpm and then just die. So I went around and talk to some guys and 2 of them told me the same thing about the coolant temp sensor.

Buy BWD Coolant Temperature Sensor WT5058P at Advance Auto Parts

Both told me if that goes bad the car will think that it is always starting dead cold and will add in more fuel then what is needed. I change it out reset the computer. I started it the first time and the idle still sucked was kind of mad at the moment. So I ran the car around town for about 30 minutes. Went back home and let the car sit over night. Went out to start it the next day and it stayed idling around 800 to 1000rmps. No idle problems sense then. The location for this sensor for me was on a metal pipe between rubber hoses going to the fire wall. If this doesn't help you you could always check your air charge temp sensor.

Buy BWD Air Charge Temperature Sensor WT385P at Advance Auto Parts

As I said not sure if this will help you because the only code i got off of my car was 111 which is a system pass. Test was done when car was not running. The other code I got was a 224 which is erratic IDM input to processor. that one happens when car is running. Also I don't know how to check if these sensors are bad or good. So you might want to find out from some one else if there is a way to check them before you go spending money.
 
1 - 4 of 4 Posts
Top