3.0 valves AGAIN

[crf250r6]

What your sayin about the valves makes sense, I just don't see how the cats can be pluged up that fast, but ill still check them, I guess I should try to find out what ford changed in these years and that will probly be the problem. I don't see why they would change the tune of the engine, I do know the intake on mine is plastic to where on 03 and older its aluminum, so theirs got to be other stuff diffrent.

 

[stmitch]

I think they changed the valves in 02 maybe. They went from like 8mm stems to 7mm stems or something like that. Also switched to "beehive" style springs. I don't see how that would make a difference in fuel burn, or cause a lean condition though.

As for the cats, I think that your previous problems have had quite an impact. Dumping fuel into the exhaust after burning the valves, will melt cats pretty quickly. So if they're the original cats, and they haven't been checked, they could be damaged as a result of your previous issues, and also could be contributing to your current problems.

 

[crf250r6]

thats true, but how can they get burnt so easily the first time, seeing is how i know 3 people it happened to.

 

[rurouni20xx]

the plastic upper plenum is supposed to breath better believe it or not. thats part of the reason i bought one for my 93 ranger the other day, that and the throttle in my upper plenum (throttlebody and upper plenum in those yrs was one piece and you cant get it anymore) liked to stick wide open. the chamber was redesigned on the flex fuel models with the valves/valve springs (i forgot about the diameter stem change thank you for reminding me). this was in an effort to run the e85 which required a little tighter compression to run correctly. the tune for the fuel was also leaned. now that you mention it there is a flex fuel sensor somewhere on the truck that determines which fuel you have and changes the tune. e85 requires a lot richer tune (or compression from hell) to run well in a motor, if that sensor is skrewd up and your tune is off there that may have something to do with it. for example your gas stations say that they can contain up to 10% ethanol, but when you actually test some stations its been recorded as low as 2% and as high as 20%. i have an ethanol tester at work (pretty neat actually just a test tube with marks on it you add tap water and the gas/ethanol/water seperate and tells you the percentage) and ive recorded as high as 15% before. if this trips or partially trips the sensor then you could have an issue there. your truck isnt flex fuel tho is it?

 

[McCormack]

Stiffer valve springs will not cause the valves to stay on their seats longer... the cam profile decides how long the valves stay on their seats, and all the valve springs do is to keep the valves (via rocker arms, pushrods, and tappets) pressed against the cam. If the valves were floating and staying off their seats on a regular basis because the stock springs were weak, then the valves wouldn't last very long and would destroy themselves and their seats in short order.

Beehive valve springs main purpose for being is to control spring resonances at very high RPM's, and high RPM's is not a problem that stock 3.0 owners have to worry about.

 

[crf250r6]

Right I don't think rpms has anything to do with it, and I don't know if its flex fuel, I don't think it is. So it sounds like its a combination of the head change and it running leaner, and it also sounds like maybe a sensor started goin out around 50k then causing the valve problem at 60k, and since it didn't get fixed it happening again 10k later, but after the heads were fixed the cel didn't come on at all untill the problem came back, so how do I find what's triggering this.

 

[rurouni20xx]

start with simple things, have your cats checked, change o2 sensors and check your egr (if equipped). make sure it is not a flex fuel model and clean your maf (just in case there may be some air filter oil on it, just a hair too much on the filter can ruin anybodies day.) then after having the truck repaired to monitor your own afrs i would install a wideband o2 sensor that gives you direct feedback from the manifolds afr. if it is still lean then you can go have it programmed and richen it up to help. little experiment for you, find a heat gun (not the kind you use to remove stickers the one you point a laser at something and it tells you how hot the object the laser is pointing at) and point it at the base of your heads, around the spark plug holes is a pretty good place. take a reading after driving say 10 miles, if you determine the truck is lean and have it programmed to richen it, take another reading and see what temp the heads are. a few degrees goes a long way in saving an engine. what temp is your thermostat for shits and giggles? where on the gage does the needle stay when driving? if it just says c-normal-h like mine if you can remember tell me which letter on normal does your gage read. mine stays around the o/r and if its hot around r/m ive never seen it go above m. my dad never changed antifreeze in my truck just put in colder thermostats. it got to the high side of m and i decided to change the antifreeze since it was never done. the dam thing after changing it (had to pull the lower hose to drain the draincock was full of rust and needed out bad) would not come off cold, had a 160 degree stat in it. went back to the 195 stat and runs great around the o/r after 280k. changed antifreeze at 230k btw.

 

[wvfarmboy]

do you think when the valves were refaced thay were ground to thin... or timing is off.or exhaust restricted.. i have known these 3.0 motors to go way over 200 k even known a coupel to go over 300k these are good little motors

 

[crf250r6]

http://rogueperformance.com/IntakeAir.html, go check that out, that sounds like it could help me, but i dont know what it is im putting in lol.

 

[crf250r6]

and how do you tell if its flex fuel and what is e85

 

[stmitch]

I wouldn't suggest adding new mods (other than maybe a tuner) until you get your current setup to work without problems, and you know everything else is working properly.

E85 is a fuel mixture of 85% ethanol (alcohol) and 15% gasoline. I run it almost exclusivley in my truck. It's typically cheaper than regular unleaded, and at about 103-106 octane can give a small boost in performance. It's also GREAT at cleaning the fuel system out, because of the alcohol. The primary drawbacks are lack of availability, and a drop in fuel mileage (which usually offsets the price difference). Because Ethanol is made from an organic base (typically corn, but cane sugar waste seems to be a better long term option) it is readily available here in the corn belt. You may have more difficulty finding it.

To tell if your truck's flexfuel, there are many subtle signs. Most have a sticker on the inside of the gas door that says you can use e85. Many of the older trucks have a small leaf badge on the tailgate but I'm not sure about the newer ones, and the most definite way to determine if your truck is flex fuel, is to look @ the VIN. If the eighth digit is U, then it's not flex. If it's a V, then you are the proud owner of a flex fuel ranger.

 

[Rearanger]

It's typically cheaper than regular unleaded,

Thanks to federal tax subsidies.

 

[rurouni20xx]

u sure that shit is cheaper? regular unleaded is 2.54 a gallon and last time i see e85 (when it first came out and they only had it at one gas station in baton rouge) was 5.44 a gallon. granted at the time gas was 3.23 a gallon here and diesel was still cheaper than gas (which it should always be since diesel is a byproduct of producing gas in the first place) but i havent priced it lately. then again ive never found another station and that one closed. ive heard it is an excellent race fuel for high compression engines or turbo cars, wanted to try some in a few quads and see how it does. the only thing that turns me off about alcohol based fuels is the fact that when they burn they produce a sugar that eats aluminum. ive torn down many race bikes that run oxygenated and alcohol based fuels to do top ends. all of which had half the piston top the chamber and intake/exhaust ports ate to pieces. you can rehone the nikasil cylinder and reuse it, and you can also reuse the head, but i really wish i had some pictures to show you the carnage after 200 hours alone. i mean 1/4 inch pits in places esp around the valve seats. the other thing is even in the manuals they tell you if its a flex fuel vehicle and is designed to run regular grade fuel, the lower compression ratio makes it to where you have to run 2 tanks of e85 to make the same mileage as one tank of regular gasoline. this is whats written in my fiances 2005 chevy silverado manual, look it up yourself. its just like running premium in a low compression engine, the fuel is designed to atomize better and lean itself. to make the same fuel burn slower and kind of diesel like regular octane does you have to richen it to thicken the mixture. thats why when you pump premium in your truck that calls for regular the mileage goes down, the system richens itself up so it doesnt ping.

 

[rurouni20xx]

aha you found the intake air temp sensor mod (resistor in the sensor line makes the engine think its running colder air and richens the system up). so your looking at richening the tune without a programmer using the stock tune? well heres one problem with that, ever seen a dyno sheet? you notice its not all smooth curves its got fluctuations and such in it? thats from imperfections in the fuel/spark tune. if youve seen a dyno sheet with an afr chart below it you will see what im talking about. to accurately tune the engine out across the board you need to be able to modify portions of the map to get rid of these imperfections and smoothen out those lines across the board. hell you can even make a perfect 14.7 across the afr line with a tuner. the iat mod however your simply richening the whole tune, moving the entire imperfect curve down a few clicks. the problem with doing that is you still have lean spots in your tune, you just richened the whole curve a hair. if you put your truck on a dyno and tuned it that way, to get a 14.7 (thats lambda or perfect tune, 13.8 is about as rich as you would like to go without too many plug problems) depending on how bad of a lean spot you have you may have to drop the intake air temp reading down as far as 10-15 degrees (ive seen spots that bad.) what you then have is the leanest spot at 14.7 or 14.5 depending on what you choose and the rest of the tune can be as low as 9.5 based on the curve. this in turn will give you rough idle, fouled plugs, cylinder washing (excess fuel washing the oil off the cylinders) and overall loss of performance and fuel economy. what that mod is is a blind tune that helps a hair usually after installing an exhaust or intake mod. the tuner on the other hand can accurately tune the whole engine out perfectly with very little headache and you get the best of both worlds: richer map and performance gain. you even get peace of mind knowing the truck is tuned correctly, not lets stick this in there and hope this works...

 

[Viper Command]

just wondering but, did you bleed out your hydo. roller lifters before installing the pushrods and rockers?