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From: Ashton Crusher on 21 Mar 2010 18:21 On Sat, 20 Mar 2010 06:12:04 -0700 (PDT), willy <danceswithbeers(a)embarqmail.com> wrote: >On Mar 20, 9:03�am, PeterD <pet...(a)hipson.net> wrote: > >> You've replaced the cap/rotor? One real possibility is moisture in/on >> the cap/rotor causing a mis-fire, when the engine warms the moisture >> evaporates, then re-condenses when the engine cools. >> >> (OK, I hope this engine does have a cap/rotor!)- Hide quoted text - >> >> - Show quoted text - > >It isn't, "the moisture evaporates, then re-condenses when the engine >cools." > >These are noted for vacumm leaks at the plentum, blown head gaskets >and fuel pressure problems. All of which will cause your symptoms. You >need to diagnosis it, instead of guessing. > I am trying to diagnose it by starting with some educated thoughts.
From: Ashton Crusher on 21 Mar 2010 18:23 On Sun, 21 Mar 2010 05:50:43 GMT, "Jim Warman" <mechanic(a)telusplanet.net> wrote: >Codes? Is it using more oil than normal? Check plugs #2 and #5 > > >"Ashton Crusher" <demi(a)moore.net> wrote in message >news:f139q5pqoneubqpu8066a75eamlufajvm3(a)4ax.com... >> 92 Ford Explorer 4.0L OHV V6 130K miles, 10K on double plat plugs, >> nearly new plug wires. O2 sensor was replaced about 40K ago >> >> Sometimes Runs rough when first started. Not just first start of the >> day, but even when warmed up and then shut down for 15 minutes it will >> often run rough initially like one cylinder is missing. >> >> Roughness usually goes away after it's warmed up but lately it's >> started to have a bucking/missing/popping under light acceleration. >> Giving it more gas usually smooth's it out. It will run on up to >> redline and shift into the next gear and has no problem running up to >> 90 mph. So unlike what I think of as the typical 'worn out plug" >> misfire that shows up at high rpm and high load, this show up at >> medium rpm light to medium load. >> >> It has not turned on the check engine light >> >> Any ideas? >> >> Things I'm thinking it might be.. >> >> water in gas >> bad gas >> bad injector(s) >> bad coil > A couple people have suggested fuel pressure regulator. For some reason it's been getting somewhat BETTER gas mileage lately, which perhaps is a symptom of low fuel pressure? And the popping, missing perhaps is also a symptom of low fuel pressure? My fuel pressure tester is loaned out so I will have to get it back and take a look.
From: Ashton Crusher on 21 Mar 2010 18:26 On Sun, 21 Mar 2010 11:23:18 -0700 (PDT), ben91932 <benteaches(a)gmail.com> wrote: > >> >He said it doesn't turn the light on, so there isn't going to be fault >> >codes. >> > >Not all faults light the MIL. You can still get useful stuff from koeo >and keor routines. >Time to cover the basics... Compression and vacuum, frp, egr (if >equipped) , alt for a/c output, vacuum leaks, ect vs act, sludged >intake/pcv, dirty maf, lazy 02's, ign stuff etc >These can be a pain as the scanner doesnt always narrow things down >well. >I have fixed dozens of these by shoring up the grounds, especially the >02 ground under the intake manifold. >HTH >Ben Can you provide any more specific info as to where that ground is located?
From: Vic Smith on 22 Mar 2010 08:20 On Sun, 21 Mar 2010 15:23:21 -0700, Ashton Crusher <demi(a)moore.net> wrote: > >A couple people have suggested fuel pressure regulator. For some >reason it's been getting somewhat BETTER gas mileage lately, which >perhaps is a symptom of low fuel pressure? And the popping, missing >perhaps is also a symptom of low fuel pressure? My fuel pressure >tester is loaned out so I will have to get it back and take a look. Not sure, but a rich mixture should throw a code, probably through the 02. No experience with Ford, but the only time I had that bucking on acceleration new injectors fixed it. Rough idle in drive at a light too. That was a 2.8 in a Celebrity. Think I had my mech replace all 6 of them, and it cost me about 5 bills. I'm a little hazy on it, but it fixed it for good and I drove it until about 190k miles before rust ate it up. Did the injectors at about 140k miles I've tested injectors (Deltac II's I think) on a couple of my other cars with an ohmmeter and always got readings all over the place, but within the spec range. The ones that came from the car that was running good (for example I pulled the injectors on the cars I sent to the boneyard due to rust) worked fine in the trouble car, though you couldn't tell from the ohm readings. Just a thought. --Vic
From: CWLee on 30 Mar 2010 05:15
I had the same set of symptoms on a '99 Explorer. It took almost 2 years, and $1,400, of replacing/repairing one thing another until the "upper and lower intake manifold gaskets" were replaced. The mechanic tried that after allowing butane or propane to be released in various places as the cold engine was idling, and the fact that the engine speeded up when the butane/propane was released in a certain place suggested to him that there was a leak there, and that the leak was allowing the butane/propane to be sucked in and burned with the gasoline. His theory was that this leak was only there when the engine was cold, and that when it warmed up the metal expansion closed the leak; when the engine was cold, and the leak was there, additional air was being sucked in and diluting the gasoline/air mixture so much that the missing and stumbling was being caused. (What I'm reporting here is my experience, and what my mechanic told me. I have no automotive skills, and thus offer this only for consideration.) Best regards to all. ============================ "Ashton Crusher" <demi(a)moore.net> wrote in message news:f139q5pqoneubqpu8066a75eamlufajvm3(a)4ax.com... > 92 Ford Explorer 4.0L OHV V6 130K miles, 10K on double > plat plugs, > nearly new plug wires. O2 sensor was replaced about 40K > ago > > Sometimes Runs rough when first started. Not just first > start of the > day, but even when warmed up and then shut down for 15 > minutes it will > often run rough initially like one cylinder is missing. > > Roughness usually goes away after it's warmed up but > lately it's > started to have a bucking/missing/popping under light > acceleration. > Giving it more gas usually smooth's it out. It will run > on up to > redline and shift into the next gear and has no problem > running up to > 90 mph. So unlike what I think of as the typical 'worn > out plug" > misfire that shows up at high rpm and high load, this show > up at > medium rpm light to medium load. > > It has not turned on the check engine light > > Any ideas? > > Things I'm thinking it might be.. > > water in gas > bad gas > bad injector(s) > bad coil |