2001 4.0 to 2003 5.9 Magnum V8 swap
- Thread starter AlaskanTJ
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- 5.9 magnum
I know you just had it done but other Magnum swap people have found that they gained some power by doing 2.25" or 2.5" Y-pipe into a 3" pipe to the cat (if you run one) and 3" into and out of the muffler... And I can attest to this allowing the engine to breath better.
I'm running the factory cat from the donor, and I'm happy with the power I've got now. My more pressing concerns are figuring out why I have some misfire codes, and why the transmission isn't shifting properly.
I misread the dipstick and accidentally overfilled it by quite a bit, which gave me quite the shudder when it tried to shift into overdrive. When I got it back home I dropped the pan to get the excess fluid out and check for debris. Thankfully I didn't find any, but while I was in there I decided to do the band adjustments, since this transmission has ~143k miles on it without any real service other than a solenoid replacement done on it. I also adjusted the TV cable as it wasn't aligned properly after I replaced the cable end. With all that done and the fluid level set properly, I'm still getting weird behavior from the transmission. Even very light throttle applied at speed will drop it out of overdrive and at low speed it doesn't seem to know whether it wants to be in 1st or 2nd. I'm gonna mess with some more throughout the week and hopefully it will be running good enough to take it back out this weekend.
That's cool I'm just passing on what others have found...
I know you said that you had adjusted your TV cable but if you haven't verified it I'd go back and readjust it just for grins & giggles...
Misfires can be caused by spark plug wire routing or a blown plenum gasket.. Here's the TSB's I found on this.
I adjusted the TV cable this weekend while I was doing everything else, but I also tried making it tighter to see what would happen today, so I'll probably just put it back where it belongs again.
I did the plenum gasket on the truck a year or two ago so hopefully it's not that again. At least if it it'll be a lot easier to get the intake manifold out this time.
While I was working on the Jeep this weekend I did find one of the spark plug wires resting on the exhaust manifold, so I had to swap that out with one of the old wires.
When I first did my swap with the 5.2 I ended up with 3 bad PCM's before I finally got a good one. I understand yours is not that issue since it came out of a good running/driving truck... Which would also most likely exclude things internally with the transmission... So I would look at wiring since I really don't think the TV cable could be the issue but I also can't say it isn't.
But I don't know what wiring since 1-3 gears are hyd controlled from what I understand and it's only O/D that was electronically controlled.
I had a plenum gasket blow like 14 months after I'd replaced it on my 5.2. Then I'd found out one of the reasons they would blow was that the bolts used were just a smidge too long & were bottoming out so wasn't clamping the plenum plate enough. I switched to a Hughes kit after that and didn't blow one again.
Then my next issue was the overheating caused by the cracked valve seat.
I used the TSB for the plug routing and it seemed to help but honestly in the 7 years I had the 5.2 running in my TJ IMO it never ran correctly. But I was also ignorant about the fuel sync. Mine ran rich enough that it clogged up a brand new cat in 3 years.
Hope you can figure it out as I know how frustrating it can be.
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