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The motor makes no noise, except rough at idling and misfireing.
I have not done a compression test. That will be next I suppose.I'm not a mechanic obviously, but I do try and can do a few things. A compression test I have never done. I'm thinking about having a mechanic look at it and do a compression test on it.
A question, can a vacuum leak create misfiring? I know It can cause rough idle and poor engine performance.
I'm missing something. I cant afford to throw parts at it. Cleaning throttle body maybe? I'm just guessing here.
nothing worse than the wife saying I need my explorer back and I cant get it up to par.
Last edited by mapleleaf1773; 11-12-2018 at 11:24 AM.
Just went back and read... forgot about the PO174 code. One thing you could have going on is a bad intake gasket or crack in the intake runners for those 2 cylinders. You could start by pulling vacuum at idle to see what you get.... IIRC, the 4.6 should pull around 20 hg's at idle. Cleaning the throttle body does no good here for fixing a misfire. It is something specific to the 2 cylinders. A mixture of soapy water in a spray bottle is also handy here..... spray down cylinder 4 and 6 intake runners while it is running and look for bubbles. Some guys use propane and listen to see if the rpm's go up when the gasses are pulled into the intake. You may be tempted to use carb cleaner here.... don't.
Ok, stopped raining for a few, went out and sprayed soapy water on the intake runners cylinder 4 and 6. Doesnt seem to be the issue. No bubbling at all. Good idea though
I cant find any vacuum leaks. I really dont know where too look exactly. I'm just tired of starring at this engine. I need to take a step back and a break for the day, ugh. I'm not making any progress here.
I've decided to replace the 12 year old fuel injectors. 1 because they are old and I (and the wife) haven't kept up with occasional injection cleaner. 2. I've replaced the spark plugs (recent) and coils ( in the last 1.5 years plus 1 brand new last week). 3. I dont think I have vacuum leaks. Although I got a P0174 code once, but not at the moment.
In swapped coils and fuel injectors this week the engine light started to flash (aka not constantly on). I'm taking this as zero fuel being sprayed in at least 1 cylinder and/or alot of fuel being sprayed in at least 1 cylinder. Either way, those injectors are getting replaced.
I gotta start somewhere. Im thinking I have multiple fuel injector issues. Might as well be the parts I've never replaced.
only thing left is a compression test and that will be my last ditch effort before I go crazy....ugh. No engine noise, just vibration on idle and driving.
Last edited by mapleleaf1773; 11-13-2018 at 09:38 PM.
One nice feature with EFI is that if you crank it over with the pedal at WOT, it won't start. It is a great diagnostic tool for "listening" to compression. If you crank it, and you can hear a nice consistent crank, chances are the compression is fairly decent. If you get a little hiccup as it cranks, it's definitely time to do a compression test. Fast forward this video to 3:18 to see what I mean by that.... some people call it a compression surge. He pulls the fuel pump relay (which I believe is for video purposes), but you can do the WOT trick.
One nice feature with EFI is that if you crank it over with the pedal at WOT, it won't start. It is a great diagnostic tool for "listening" to compression. If you crank it, and you can hear a nice consistent crank, chances are the compression is fairly decent. If you get a little hiccup as it cranks, it's definitely time to do a compression test. Fast forward this video to 3:18 to see what I mean by that.... some people call it a compression surge. He pulls the fuel pump relay (which I believe is for video purposes), but you can do the WOT trick.
thanks white, I'll try this this evening and listen. I pulled the fuel pump fuse when I moved the fuel injectors around to relieve the fuel pressure. So I'll pull that again and crank it and see how it sounds.
I do appreciate your help white. Unfortunately I had a compression test done. Cylinder 1 and 3 are testing 35 and 40. The range should be 80 to 100. To beat it all, those aren't even the misfiring cylinders.
so sad, but this 4.6 engine is one foot in the grave.
my wife is not happy. Neither am I as we are down to one car. I have a motorcycle, but damn cold.
Last edited by mapleleaf1773; 11-16-2018 at 06:19 PM.
11-12-2018, 11:06 AM
