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HP Tuners MPVI3 and a Jeep

CharlesC83 said:
I also have my 2006 LJ 4.0 licensed on my mpvi3. I haven’t done much tuning with mine yet. I have no mods to my engine. I just licensed mine cause I had the mpvi3 and wanted to be able to adjust it.

If your comfortable pulling a valve body this shift kit from transgo cleans up the 42rle shifts quite a bit.
transgo.com

TransGo - Chrysler 604 SHIFT KIT® Valve Body Repair Kit

This TransGo 604 SHIFT KIT® Valve Body Repair Kit fits 1989 and newer Chrysler, Plymouth, Dodge, Eagle, Ram, Jeep and Mitsubishi vehicles equipped with
transgo.com transgo.com
Click to expand...
I'm good with pulling a valve body but I'm on the fence about doing anything to stress this old transmission at this point. I'm *probably* gonna chance that kit when my transmission fluid is due but I'll be on the fence till I get a good case of "F-it" the week before. LOL

Really good test drive today. Couple hours at various speeds yielded a very noticeable improvement in power with just the 3 degree timing bump.

I'm going to drive it this week and next weekend I'll do a nice long log and make some more adjustments.
 
CharlesC83 said:
I also have my 2006 LJ 4.0 licensed on my mpvi3. I haven’t done much tuning with mine yet. I have no mods to my engine. I just licensed mine cause I had the mpvi3 and wanted to be able to adjust it.

If your comfortable pulling a valve body this shift kit from transgo cleans up the 42rle shifts quite a bit.
transgo.com

TransGo - Chrysler 604 SHIFT KIT® Valve Body Repair Kit

This TransGo 604 SHIFT KIT® Valve Body Repair Kit fits 1989 and newer Chrysler, Plymouth, Dodge, Eagle, Ram, Jeep and Mitsubishi vehicles equipped with
transgo.com transgo.com
Click to expand...
Are you still running the factory ECM? If you are, would you pull the tune and send it to me?

Comparing mine with a factory ECM for a 2005 MT it looks like there's a lot of timing pulled from some parts of my timing tables. I would like to compare it to a factory automatic tune.
 
Today's changes.

Added timing to the start table. +3 degree on hot and cold start.

Increased the Intake Volume by 76cc to account for the TB spacer. (varying reports of necessity online but figured I might as well)

Bumped WOT timing table by 3 degrees.

Upped the injector PW Offset up 5%.

Results: Fuel trims got very funny with the offset adjustment. I did a pretty good test drive and they really didn't trend in the direction I was looking for them to.

Also picked up some spark knock at WOT around 3600rpm on a steep hill in 3rd gear.

I came home, reset the offset table to original and dropped the WOT table back to stock. On the following test drive trims went back where they were and I still have a touch of spark knock I was able to capture with a quick log during the knock. I'm going to pull a couple degrees from that part of the spark tables and hopefully cure that.

I'm doing my tuning on regular since it's what I plan to run until I really modify the engine enough to need something else.

It appears my B2 O2 is failing. Response is getting very slow and I had a pending performance code on it last week.
 
Over the weekend I noticed my fuel trims zeroing out at 30% throttle on the interstate. It was suggested that I was going into Catalyst Over Temp and I verified that this evening.

I bumped the limits and rates up a little and made some more timing adjustments. I'll give it a treat drive tomorrow to see how I did. Supposed to go wheeling this weekend so I'll probably dump some mid grade in to play it safe with the higher Coolant and air temperatures and increased heat soak.
 
If you don’t have it yet. The heat guard kit from DEI is really nice on the 4.0l. To prevent cylinder 3 misfire hot. I used this kit and the Mopar fiberglass sleeve.

It fits the 05-06 models just fine.

Amazon.com: DESIGN ENGINEERING Fuel Rail & Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) - Our Accessories Reduce Vapor Lock & Keep Fuel Injectors & Rails Cooler : Automotive

Buy DESIGN ENGINEERING Fuel Rail & Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) - Our Accessories Reduce Vapor Lock & Keep Fuel Injectors & Rails Cooler: Heat Shields - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
a.co
 
CharlesC83 said:
If you don’t have it yet. The heat guard kit from DEI is really nice on the 4.0l. To prevent cylinder 3 misfire hot. I used this kit and the Mopar fiberglass sleeve.

It fits the 05-06 models just fine.

Amazon.com: DESIGN ENGINEERING Fuel Rail & Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) - Our Accessories Reduce Vapor Lock & Keep Fuel Injectors & Rails Cooler : Automotive

Buy DESIGN ENGINEERING Fuel Rail & Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) - Our Accessories Reduce Vapor Lock & Keep Fuel Injectors & Rails Cooler: Heat Shields - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
a.co
Click to expand...
Actually installed that when I did the 4 hole injectors. :waytogo:

20250406_125314.jpg
 
When I put the hard top on for winter, the spark knock was much more audible and I pulled a bunch of timing out of the tune for safety.

My middle daughter got her learners permit last week and she got roped into some driving for me today so I could do some logging and get my timing back.

We did a couple high RPM, high load interstate hill climbs and after a couple of flashes, I think we got it pretty dialed in on top. There MAY be a little knock down low but without a knock sensor it's hard to distinguish from, well, normal Jeep noises.

I've been waiting for the 14point7 WBO2 to come back in stock but in the mean time, I've been looking at the Innovate LC2 as well to help dial it in.

I'm not sure what engine is in this thing and what shape it's really in. It doesn't use oil and the oil is very clean, even at neatly 4000 miles. But it kinda acts like it has a weak cylinder occasionally. Not a full on miss-fire, but just a miss-esque surge.

It also REALLY doesn't like turning over 4000 RPM. It just falls flat on its face. With 5500 red line, I would think it would get closer. But I haven't had a 4.0L in years so I'm not sure. But I think a little head work, a cam that focuses less on idle power (automatic) and a header wouldn't hurt in the future.
 
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