TOPIC: Jeep 4.0, 4.7, 5.2

I want to ask if anyone has results in mileage increasing on these engines of JEEP 4.0, 4.7, 5.2 Please write here.

The 5.2 in a dodge ram showed about a 20 percent increase 4x4. A jeep maybe diff as it could be geared lower,but the engine should be the same. If you do any of these please keep us all posted. dan gadgetman mo.

Hi from Saskatchewan. Just finished mileage check after first groove on a Jeep TJ 2.5L. This was the 3rd time trying to get the angle right because of the venturi style throat below the plate. I ended up opening up the throttle plate about 1/16" to increase the angle and slid the cutter straight down the plate. 0 to 60 mph was over 1 sec. faster, 60 feet shorter, LTFT down to -8 from 4, and mileage up 25% (17.5 to nearly 22mpg). Plugged pcv and re-routed IAC.

Just working on my 4L Cherokee. Started with +4 LTFT, went down to -12, but for some reason back up to +4, with power the same: probable new major vacuum leak. Will check hopefully today.

Luke

Hi there,

I have a 1998 TJ Wrangler with a 4.0 engine. I installed the Groovy TB on it 2 weeks ago. So far in 1 tank (12.5 gal) I have increased MPG from 10.13 to 12.26.

My engine MODS are as follows:
*Edge trailjammer cold air intake (Using an OEM grooved TB instead of the 62mm that comes with the kit)
*Edge computer chip for 1998 Wrangler TJ's
* AirAid TB spacer

I like the increase but was hoping for more. I capped off the CCV (has 2) locations on the valve cover and left the TB spacer and computer chip installed. I now have pressure in the oil pan and get sprayed with oil when removing dip stick. Did not have this issue before capping CCV lines.

Anyone have a clue as to how this is fixed?

Jetmech3

Are you sure your not blocking the passive and pressure lines from engine? only plug the vac and take pressure to air snout. As far as mpg did you try without chip? Some of these will limit the mpg increase as they are preset maps for ecu to follow sometimes you get better mpg stock with groove.
As far as the spacer Id take it out as it will change the waveform, the only reason for them is if you can`t groove due to lack of room after butterfly. Ron had a pile of them he`d taken off when I was in Arizona with him. I would expect about 18mpg plus. Happy grooving.

I second Dan, pull the spacer, think about using stock chip. Definitely don't seal the crankcase, follow the PCV re-route procedure. Block off PCV manifold vac. source. Run PCV valve hose into passive breather hose that goes from valve cover to air intake duct.

Tracy G

Thirded.

Anything The Groove hits will diminish its impact. Any electronic modifications can limit/eliminate gains. Ensure the crankcase can be allowed to vent.
You will want to do the recommended research, and follow the links in the training manual. The more you know, the stronger your abilities.

And please, use your real name. At the very least, please sign your posts, Eddie. We want to get to know you! If you like, I can change your Username for you... Let me know.

Ron

Hi Ron,

Copy the "name on posts" request..

What I have changed to date:
*New "OEM" header on today. I had a "Banks" and it cracked in 3 years. Original took 10 before going bad so I figured...what the hey...go original.
* Removed the TB spacer and the Edge computer chip
* Reinstalled the crankcase VENT
* Installed a new brake booster and master cylinder
* Reset the computer (again) and filled up the tank
* Changed the oil pump and rear main seal (had oil leak at rear seal. Jeep has 111,120 miles and the oil gauge was starting to fluctuate more than normal, so I changed the pump while I was down there with the pan off)

I have done all the above in the last 7 week. That is why I rest the computer again. I will start monitoring the MPG as if I just installed the TB mod. Already (new parts) I can defiantly feel more power to the wheels.

Will post again in a few weeks and report 2 tanks of gas results.

Later gators! Keep a MOD'in!!

Mr.Ed (AKA....EDDIE)