Stumbling Idle | Page 3 | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Stumbling Idle

Crazy thought: Can the TPS cause pinging? Because I know it can cause it to stall or idle weird, which it is doing.
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





TPS usually causes deadzones during acceleration. Like you hit the gas and it will stumble and then clear up at a point. Think of it like a volume knob (it's a potentiometer) but at 11 o'clock there's no volume then 12 is normal.

I guess it COULD cause an idle issue. Easy to check though, stick a multimeter on it. You don't even need the engine running, just the key on.
 






Right now, I am thinking it could be one of four things. I haven't worked through them all yet. The TPS, IAC (doesn't directly address the pinging), EGR valve, or ICM.

Here's a rundown on new stuff: New DPFE, new MAF, new PCM temp sensor, ruled out EGR solenoid for now, fresh ethanol free gas. It will stall occasionally (like if the AC compressor kicks on at a red light, or going from forward to reverse, or sometimes it will die when it's first started if you don't give it gas for a few seconds). Also, the pinging is a bit extreme. I get ping accelerating from a light in town, not even really pushing it. The limit is 35 mph. :p I'm hoping it's one thing that fixes both problems...I will check out the TPS.
 






The TPS takes 3 minutes with any voltmeter to test, so definitely do that. As I said earlier, take the vacuum line off the EGR valve and plug the line with a screw. If it gets better, you have an EGR problem. The EGR valves are spec'ed to be replaced every 50k anyway, although most people wait for a problem. Another test to see if the EGR valve is stuck is to take the vacuum line off, and plug it. Then take another hose and put it on the EGR valve. Start the engine and suck on the tube. If the engine starts to run rough or stall, your EGR valve is free.
 






I'll definitely be trying that, as I still suspect it. Thanks!
 






Pinging spark knock and detonation are all having the same symptom.
1. Weak spark (cause by spark plug, wire or coil pack)
2. Unburned air inside the combustion chamber. (cause by vacuum leak, exhaust leak) "lean condition"
3. unburned fuel or raw fuel in the combustion chamber -can damaged catalytic converter. Caused by leaking fuel injector or exessive pressure from fuel pressure regulator or fuel pump..)"rich condition"
temporary fix is: to add some octane booster to your fuel tank
 






Beginning to think I'm just getting some gawdawful gas. Everything checks out. So, I'm going to run this gas out and try something different, unless I stumble across something I missed. Or things worsen (please don't worsen). :p

Oh yeah, also going to replace those double platinum plugs I learned were in it with OE Motorcraft single point platinums.
 






You are trying 91+ octane correct? If it still pings with 91, its not the gas.
 






No. Not at the moment. I was trying to go down to the recommended 87 octane, as it -should- be able to handle it. This last tank must have been bad, though (got it from a different place, was in a rush). So, back to better gas.

I was thinking since it was so severe that it could have been another issue. But, I will get better gas and monitor for improvement. On Premium, it pinged far less. But, all things seem to be working. If it continues, I might take the intake apart. But as of now, my plans are changing to Motorcraft plugs. The guy who did my head gasket used simething else. That could be it, too. (I assumed he would use motorcraft)
 






Normal pinging that I have always got in the 4.0 is under full throttle, at around 3500 rpm it will start to rattle a tiny bit. I did have a problem once where my 94 x would start pinging under load at cruising speeds. Going up hill made me cringe. Sure enough my DPFE quit. Vacuum leaks, EGR, and carbon build up are the biggest causes of pre-detonation in my opinion. Bad gas can certainly do it too, but you can usually smell it if you cant see it. Gas turns piss yellow, and smells like varnish when it goes bad.
 






I have to say the smell coming from the exhaust has been potent. Not like a bad cat at all, but "different", and only simce I bought gas there, come to think of it. But the pinging, like I said, was alarming enough to make me think something gave up. I did replace my DPFE, though. I still want to replace those damn double platinum plugs, though. That irks me.
 






Oh yeah, also going to replace those double platinum plugs I learned were in it with OE Motorcraft single point platinums.

Don't bother doing single plats. One bank will wear worse than the other and you'll end up having to replace them just as soon as regular plugs. Go double platinum or copper. Single plat is a waste of money on these DIS systems.
 






Go for OEM spark plug.
 






I just go with regular plugs. NGK, Autolite, or Motorcraft are good, but I've ran others without problems too. NGK TR55 is my first choice.
 






Just use oem parts to your igntion. double paltinum or e3 they're a bunch of crap.
 






I agree there. I have nothing but bad luck with "upgrades". It gets what it came with from here on out.

I did learn that much of what I experienced was -horrible- fuel. I filled it with Premium. All symptoms are improved. I consulted a mechanic I've known for years, and his advice was to burn Premium. Said he knows someone who has the same issues with the same engine.

I've read the Ford TSB, but with the fuel available here, Premium might be the best option. So, to combat the carbon buildup Ford cites as a potential issue, I will just Seafoam it every so often. Perhaps every other oil change or so.
 






Back
Top