TOPIC: Re: No improved gas mileage

HI Dan, I took the egr line off from the intake and plugged the intake but it didn't make any difference in vacuum. I just went through my fourth tank of gas since the groove and the mileage still hasn't increased actually it's gotten a little worse.
Do you have any more suggestions of what might be wrong?
Nathan

okay put everything back to norm egr pcv everything but groove.If you have access to car scanner give me the fuel trims the ecu is not cooperating reset the ecu by taking off batt cables. next test drive and see if gains start the car scanner will tell us without driving but if no acess then you must drive. if you check fuel trims check at idle and 2000 rpms no load is ok this will really help us. dan gadgetman mo.

Hi Dan I put everything back to the way it was before except the groove and I took it in to get the fuel trims.
The short term at idle was -1.6 to 1.4, at 2000 RPM it was -7.8 to 0.
Long term at idle was 3.3 and 0.4 @ 2000 RPM
Nathan

looks like those numbers are going to cut fuel, test drive for awhile and I think you`llproably see some gains.dont be agressive for the first 100 miles or so so the ecu has time to lock in fuel trims. dan gadgetman mo. keep us posted

Nathan,
I just grooved my 2005 Chrysler 3.3L van and am not getting any mileage increases. I set plug gap to .060, replaced both oxygen sensors, disconnected the pcv and blocked the EGR valve. I also conditioned the ECU. I have ran one tank of fuel thru the van but haven't seen any increases yet. My engine light did come on. I have an engine scanner ordered and will read the code when I get it. I checked vacuum on the brake booster, it held 20". I checked vacuum in the intake manifold at the brake booster nipple, the manifold held a solid 20" when idling. I'm not sure where to go or what to do from here. Did you ever get your 3.3 to show some reasonable gains and if so, what additional did you do ? Thanks

Roger - how did you block the EGR? also, please show pictures of your re-routed PCV system - I would just like to verify that it has been implemented as per the manual.

On the EGR line, I cut the pipe that went from the engine block to the intake manifold. I then plugged the portion that went into the manifold. The other end appeared to have a pump mechanism on it. I put an angled fitting onto it and routed it toward the bottom the engine compartment. I know the manual stated to leave it alone but when I opened up the throttle body, it was absolutely filthy with a brownish, tarry substance covering everything engine side of the butterfly. I just couldn't see letting this filth continue to be drawn inside the engine. A side note, I have a 2007 Chev duramax pickup and they strongly encourage owners to block the EGR system. I didn't until at 75,000 miles my turbo froze up from the same tar filth. $2,000 later I'm back running but with an EGR blocker plate. That was my reasoning for messing with the EGR on the van.

The PCV valve, the manual addresses several spots that I found. One said to simply put JB weld into the PCV valve, effectively plugging it and then put the hoses back in place. The other talked about rerouting the system. I understood, leaving the valve functioning but not going into the intake manifold, instead, reroute it so it enters the airstream between the air filter and the TB. I split the difference. I took the hose off the manifold fitting and plugged it securely but then installed an elbow fitting and just vented the PCV into the open air.

There is 180,000 on the 05 Town and country. I put both new oxygen sensors in it, opened the plug gap ,010 to .060 (.050 recommended), checked all the vacuum lines coming out of the manifold and they all held 20" vacuum. After warming up the engine, I attached my mityvac to the brake booster nipple on the intake manifold and the vacuum held right at 20". So I'm assuming my intake manifold gasket is good if it will maintain that solid reading. I also did the ECU reprogramming, following the manual precisely.

The good news is that on the third tank of fuel after the grove, the mileage came up. The van, pregroove, on paper was getting 24 mpg and that is also what the digital overhead gauge was reading. Now the gauge is reading 32 on level going. I've noticed the fuel gauge is dropping substantially slower also but I haven't put enough miles on it yet to figure it out on paper. It appears that something positive is happening mpg wise. Appears it just took the ECU some time to reprogram. Thank you for responding to my issue, which it seems may now be a nonissue. I'm open to any suggestions.

I've got a 2014 T & C, 3.6L I've looked at grooving but there are about twice the wires and plugs and cables on that one vs the 05. I'm a little intimidated to start that project. Has anyone done one of those with decent results ? Anything to pay particular attention to ? Thanks

Thanks for this expansive replay, Roger! It demonstrates exactly the thought processes and actions (reporting) that every Gadgetman should follow. (+2 Karma!)

Now, on another note, I have been cogitating quite a bit on the PCV valve issue of steam causing apparent soiling of the oil inside the engine. This is true, but only to a limited extent (it rises, so it doesn't actually mix with the oil-it only mixes with what's coating the surfaces OUTSIDE the oil stream).

I have been working with a gentleman (pre-groove) who has been following my pointers. He's driving an 03 Chev 2500 with that glorious 8.1 L with the internal PCV valve. Following my instructions, he was able to increase my a meager 15% or so, and in the process of exploring how to eliminate the PCV system's main negative effects, it was revealed that he has been leaking about a quart of oil every 1,000 miles. As I thought on this, I realized that we may be able to solve for his poor mileage (7.9 mpg's is his record high) AND for his leaky system in the same move.

Instead of plugging off the PCV end of the system, I recommended he plug off the intake portion at the breather opening. In this model it's very simple and can be accomplished by simply removing the intake air tube from the throttle body, exposing a rather large hole in the left lower quadrant. Simply insert an appropriately sized rubber vacuum cap into the hole and (to ensure it doesn't wind up in the intake manifold) insert a bolt to expand it beyond the point it can move inward.

Not only will this still achieve at least a portion of the goal (complete elimination of the vac drain), but will allow enough vacuum to reverse the pressure on his seals, retarding his leaks.

He did so, and called me within fifteen minutes of being into his test drive, reporting already seeing noticeable increases in all dynamics.

The reason this is relevant is the goal if DECREASING intake pressure by all possible means MUST be attempted. Every time we do, our engine efficiency AND LONGEVITY will increase.

Gentlemen, I salute you all for your efforts. Especially you, Roger.

I could not be more happy to call you my Brother Gadgetman.

Ron

Ron - If I understand what you're saying here about this PCV re-route/mod, you're letting the stuff the PCV system is there to evacuate leave, but you're not bringing clean air in through the breather.
To put it another way, by eliminating the "supply side" (clean breather air) from the system, the vapours move of their own volition within the system, but also in a variable fashion in conjunction with the movement of the throttle plate, keeping the system dynamic, but also negative pressure.
Do I have that right?