Stumbling Idle

[FR-425]

Another mod I'm thinking of is making a reducer plate for the EGR valve itself so even when it's wide open it can't choke the engine with hot exhaust gasses so bad that it starts pre-detonation like it does now.

I tested my theory by pinching off the vacuum line to the control servo so the EGR valve would remain closed, and presto no more knocky knocky.

CEL codes like mad but no pre-det.

If I do the restricter plate I think I can have it both ways, No CEL, emissions pass and a fail safe for when the EGR goes bat-nuts.

 

[Wolfie_85]

I still have my issue after changing the DPFE. Not sure what else it could be, short of the EGR valve itself. I -really- don't want to have to replace it after reading the tube bending expensive nightmares.

 

[FR-425]

Did you disconnect the battery to clear the code?

Next question: do you still have the 558?

 

[Wolfie_85]

I've replaced the DPFE. It still had the 558 code, I noticed the connector to the solenoid was missing and had been rigged with slide-over connectors that fit over the prongs. Thinking they may have been hooked up opposite of how they should be, I switched them. The code went away, the pinging did not. Put them back as they were, code came back. Still pinging.

I'm officially lost if changing the PCM coolant temp sensor doesn't solve it. Seriously, what else could it be? The idle issue stopped with the new DPFE. But that's the -only- thing that improved. The MAF is new as well. So is the PCV valve. The pinging has reached an unsettling level.

 

[FR-425]

What kind of spark plugs do you have?

The reason I ask is that these engines are known to be easy to get into a ping situation by simply using the wrong plug. Or just when the plugs get to much carbon deposits on them. Even just normal looking but aged plugs in mine and the pinging gradually gets worse. So now I change them every 6 months or 10k miles or so.

I stupidly put some of those e3 plugs in mine and it pinged straight away. Had to go.

The preferred plug is just stock autolites.

The other possibility is that the EGR valve itself is stuck open. (rare as hens teeth but possible) Some gentle taps with the BFH may just break it loose.

 

[FR-425]

Removing the right front tire makes spark plug changing much easier.

You can get at the right bank from the wheel well far better than from the top.

 

[Wolfie_85]

The plugs aren't anything odd or fancy. I keep it OEM. I shall try tapping the EGR valve.

 

[FR-425]

Maybe you just got a load of really bad gas?

 

[2stroke]

You can simply take the vacuum line off the EGR valve and plug the vacuum line. The EGR will stay closed.

 

[Wolfie_85]

I replaced the PCM temp sensor, and tapped the EGR with a hammer to see if there was any change. None really. Though the temp sensor seems to have boosted performance a bit, it still pings more than it should. I did notice that the EGR valve itself looks a bit rusty on the outside. Not sure if that indicates anything about the inside...

So...gonna get some (different) gas once it gets a bit lower and see if that helps the pinging.

 

[xplorernewb]

not sure if this has been covered yet, but if your egr valve has a diaphram on it, just squeeze the diaphram and cover the vacuum and if it holds vacuum (you'll either hear it or feel the vacuum diminish) its good, if it doesnt its bad. if there is no diaphram, you can hook up a small amount of air to it via vacuum pump with gauge and see if it holds. just dont do too much pressure or the diaphram could tear and it will become bad if not already. just block the passage way. done this on other cars, just not on an ex so dunno if its the same

 

[Wolfie_85]

So, how common is it for a bad IAC to cause ping?

 

[FR-425]

IAC won't affect pinging.

As soon as you touch the throttle it has no effect on the mixture at all.

 

[FR-425]

I replaced the PCM temp sensor, and tapped the EGR with a hammer to see if there was any change. None really. Though the temp sensor seems to have boosted performance a bit, it still pings more than it should. I did notice that the EGR valve itself looks a bit rusty on the outside. Not sure if that indicates anything about the inside...

So...gonna get some (different) gas once it gets a bit lower and see if that helps the pinging.

Rusty EGR is par for the course.

So is ping on this engine.

I run mine with the octane shorting bar removed from May through September here in Phoenix. Once were off the ethanol I can go back. The power loss is negligible. Fuel econ drops a tiny bit but that's because I can push it to the floor without fear.

 

[Wolfie_85]

Oh yeah, I wouldn't worry about the ping if it was light and at highway speeds when I gas it. This is now at the point where I get heavy pinging accelerating at 35 or 40 mph. Not comfy with that.

No code currently being thrown, octane bar is pulled. It also stalled today at a red light when the AC compressor engaged. The compressor is fine. It did it later when I put it in reverse and turned the wheel to back into a spot with the air off.

 

[FR-425]

I replaced the PCM temp sensor, and tapped the EGR with a hammer to see if there was any change. None really. Though the temp sensor seems to have boosted performance a bit, it still pings more than it should. I did notice that the EGR valve itself looks a bit rusty on the outside. Not sure if that indicates anything about the inside...

So...gonna get some (different) gas once it gets a bit lower and see if that helps the pinging.

Yet to see one of these EGR's actually fail.

Note: when my DPFE goes the EGR goes wide open and I can't even get to half throttle before it starts bang'n scary loud.

So if your just getting short rattles at shifts it's as good as it's gonna get.
(except for pulling the octane shorting bar.)

Even with it out I still get some pinging but not severe. Ford say's this is normal and is not gonna kill the engine. (at least not a low mileage engine right?)

 

[FR-425]

Oh yeah, I wouldn't worry about the ping if it was light and at highway speeds when I gas it. This is now at the point where I get heavy pinging accelerating at 35 or 40 mph. Not comfy with that.

No code currently being thrown, octane bar is pulled. It also stalled today at a red light when the AC compressor engaged. The compressor is fine. It did it later when I put it in reverse and turned the wheel to back into a spot with the air off.

Now that would be a bad IAC, when the compressor engages the IAC is supposed to bump the idle to prevent stalling. (also when shifting at idle)

Not sure if that is going to deal with the bad pinging though.

I'm staring to suspect the ICM. If the ICM has failed into "limp mode" the pinging gets out of control as well. But other wise runs "normal" If it is bad you are going to be in for a nice surprise when you get back about 80 missing horse power!

 

[FR-425]

A bad ICM will not throw any codes.

And there is no real way to test it, but to swap it out.

Huge oversight on the OBDI set up.

I now carry the "limp mode" one as a spare. It'll get ya out of the woods kinda thing.

 

[FR-425]

It's worth saying that mine is gradually developing a stronger ping between 2200 and 2700 rpm. I suspect the Fuel Pressure regulator and/or failing fuel pump causing it to lean out at higher rpm.

So those are next. I have not replaced them since I bought it and their on the "used car and you didn't replace that?" list.

 

[Wolfie_85]

Now, ICM is something I didn't think of. Gonna try cleaning up the IAC.