Explorer v6 still acting up

[Papasmurf]

Hey guys been lurking for awhile and I thought I would sign up. Well I picked up an 02 explorer 4.0 for real cheap and the exhaust valve spring on cylinder number 3 was broken. It honestly drove fine except for being a little down on power and having an off idle.

So what I did was replace the spring after doing a compression test and put in new intake manifold gaskets. Guessed on the torque but it was probably too tight.

Well I took it out for a drive thinking the computer needed to relearn and I just new something didnt seem right. So I replaced this hos that goes right behind the throttle body, along the firewall and into some emmisions part under the fuse and relay box.

So I went for a drive and everything was fine at first got it up to higher speeds and all of a sudden it starts bucking and stuttering like its running out of fuel. Someone told me the guides were broken and the chains stretched, it does not sound like that at all, cause at an idle it seems fine, as long as it doesn't die. I tore the top end all apart and redid the gaskets and checked connections. The intake is properly torqued too. When driving around slowly it sounds like slight pinging but no codes, knock sensor maybe?

what I have done-
Motorcraft plugs gapped to factory
wires
intake gaskets now torqued properly
cleaned maf
cleaned iac valve, I also hooked it up to power to see if it was working
cleaned intake and throttlebody
replaced valve spring
new fuel filter

what it does-
bucks
surges then dies
feels underpowered
slight pinging when driving around the block or slow speeds

Ive searched and searched and tried alot of things on this site so if anyone could give me any other ideas I would appreciate it so much, thanks guys


-Shawn

 

[Papasmurf]

Before I redid the intake gaskets I was getting some codes for misfires and some code fore something about a problem before 1k? And a p1131 but no codes right now

 

[Papasmurf]

I will add that the engine shakes quite a bit at idle and never smooths out

 

[Papasmurf]

alright so now I have codes p1132 and p1151. But IM gonna run another compression test just to make sure everything is fine on that end. Anyone know what's a good range? Didn't find a number but it does have 177,000 miles on it

 

[Papasmurf]

Looks like I'm the only one in my own thread. I have well the compression on bank 1 is 120,120, 100 on a cold engine. On the shop floor beneath the tail pipe where it's been idling, it's kind of sooty only after I started revving it a little bit after being warmed up so I wonder if some carbon is being broken up from the #3 cylinder.

The only time it starts acting rough is when I put it in reverse or drive. If it doesn't die right away like it has been it will run very rough and stumble and miss. Anyone have any ideas? The iac valve is clean and it works but I have not tested power to the valve yet. Hopefully someone will have an idea or I come across something I didn't before.

 

[Papasmurf]

ran some seafoam through it, maf sensor is working, cleaned out the iac valve but ordered a new one through work just in case, checked fuel pressure and the pump is putting out 63 psi with the vehicle running. Still acts like it wants to die in gear but not as bad as before. Kinda has a little chug when cruising and that pinging around the 2k to 2700k rpm range.

Gonna dig further into this

 

[stoogefan]

P1132: Bank1 is too rich.
P1151: Bank2 is too lean.

It’s possible that one or both of the upstream O2 sensors is bad. Also check for vacuum leaks. I have read that the rubber elbow leading to the PCV valve sometimes develops a crack. Possibly check EGR valve to make sure it isn’t stuck open. Check for clogged or bad fuel injectors on bank 2. I used a mechanic’s stethoscope to locate a bad injector in my Crown Vic but I threw a can of fuel injector cleaner into a half-full tank of gas and it fixed the problem within 15 minutes.

The “pinging” is most likely the timing chain rattle that our 4.0 V6 is blessed with.

 

[Papasmurf]

The codes are not present anymore. I will use my stethoscope to check the injectors but I will say I have not done any inspections or cleaning of the egr valve or the two little tubes. I will also check the pcv valve and the tube coming from it. Carb spray resulted in no changes when sprayed around the intake and other places. Thanks for the reply

 

[Papasmurf]

Well the new iac valve fixed the problems, feels like a totally different vehicle now.

 

[Sedition]

Looks like I'm the only one in my own thread. I have well the compression on bank 1 is 120,120, 100 on a cold engine. On the shop floor beneath the tail pipe where it's been idling, it's kind of sooty only after I started revving it a little bit after being warmed up so I wonder if some carbon is being broken up from the #3 cylinder.

Your compression is quite low on bank 1 (assuming right bank) on all 3 cylinders. next time you have your valve cover off check the rear timing chain guide, if it is completely missing then your right camshaft will be over 10 degrees retarded (late). With your camshafts this far out of phase it is no wonder your engine is shaking on idle and giving you a poor power pulse.

This can be corrected with a simple timing adjustment. please see my following post. It starts at post #87

http://www.explorerforum.com/forums/showthread.php?t=271605&page=5

 

[Papasmurf]

Yeah I plan on ripping the top end apart again just to double check things but every problem I was having before is gone, noises, shakes and driveability problems. I also want to make sure the lifters are clear of any foreign matter