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The Wranglers and Grands had 4.0 engines in 02 and beyond. If that is what you are referring to, yes it will bolt on. Then you will have to adapt your power steering pump mounting to it, adapt the Renix throttle body and sensors, reroute the serp belt, and redo all the vacuum lines. Plus a lot more I'm forgetting...........

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Why do folks keep answering these threads that make about as much sense as asking how long a piece of string is?

:dunno:

 

Can you use the early 91-96 intake manifolds on a Renix? I know the ports may need a little massaging and throttle body mods. If you can, then you can use the better flowing 99-04 intakes also as the ports are all the same throughout the 91-04 4.0 years

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So using a 99+ intake on a Renix should wake it up better than the 98 and below square HO intake it seems. It sure helped my 91. 

 

Don, Know you used to dyno you truck every so often.  Do you have a dyno post before and after just the late intake manifold you could share?  Stuff I have read on, puts the gain at next to nothing or up to 50 horsepower.  I tend to think it may make for a litter more responsive low end, but no additional horsepower.  Think it was more emissions related than anything else, much like the later heads with the smaller exhaust ports to heat the cats quicker.  Cam was also changed around the same time, for the same emission reasons.  Total gain was 4 horsepower and small adjustments in the torque curve if I remember correctly.

 

Suppose I should look out for the later power steering bracket for my long planned Stroker motor.  Have the 2000 and later exhaust manifold and the intake manifold.  But don't want to choke the Hesco head with the 2000 exhaust manifold.

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Yes, I had it dynoed at Hesco after the 01 manifold install about seven years ago. Just the manifold resulted in a 12HP gain. This was on a stroker engine though with intake, exhaust, cam, etc. mods. It's unlikely a NA engine will see anything close to that.

 

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http://www.jeepstrokers.com/forum/viewtopic.php?f=5&t=387

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Thanks Don!  Bit nicer bump than I had remembered.  As long as I have the manifold, may as well get the power steering bracket and use the manifold when I finally build the stroker.

 

The other thing your link points out is the value of proper pcm tuning.  My next junk yard buy is going to be a complete engine compartment harness and pcm from a 96 OBD2 Cherokee.  Once that is installed in the Comanche, we will see about a retune just for the stock 4.0 and see what that does for the current engine.

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My next junk yard buy is going to be a complete engine compartment harness and pcm from a 96 OBD2 Cherokee.

 

Why 96? for the OBDII? Myself, I steer clear of 96s if possible, kind of a bastard year, rather not throw anything else into the mix that I don't have to. FWIW, you can flash the codes on an OBDI just as well as pluggin in a scan tool on an OBDII. And not sure but since it's the first year of OBDII, I think you have to swap the complete dash harness because that is where the ECM and OBDII connectors are.

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My next junk yard buy is going to be a complete engine compartment harness and pcm from a 96 OBD2 Cherokee.

 

Why 96? for the OBDII? Myself, I steer clear of 96s if possible, kind of a bastard year, rather not throw anything else into the mix that I don't have to. FWIW, you can flash the codes on an OBDI just as well as pluggin in a scan tool on an OBDII. And not sure but since it's the first year of OBDII, I think you have to swap the complete dash harness because that is where the ECM and OBDII connectors are.

 

 

Want to avoid the complete dash swap of going to the 97+.  More work than I want to do.  So that leaves me with the 1996 OBD2 bastard.  My main goal here is to get the engine pcm/ecu into the truck. That OBD2 pcm will allow the me to get the ecu reflashed for more power and more timing advance.  That is why I want to do it.

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John, Hesco has a CPS for OBD1 (unadvertised) that will give up to 10* advance. You just have to solder the proper connector on from your old CPS.

 

That is a whole lot of advance!  What does it do for the rest of the distributor curve?  Advance the whole thing?

 

Since you got rid of the UniChip module, what are you using now and did you take a performance hit.  You gained a whole bunch of torque with the Unichip and it changed the whole ignition curve.  Not just an advance bump. Right??? 

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The Unichip allows you to tune the MAP, TPS, CPS, and IAT outputs to the ECU. The Unichip maps are proprietary, but you can buy the program and tune yourself if you want to. I never did though; always went to Hesco for tuning on the dyno, otherwise it's just guesswork and I don't believe the butt dyno, not even my own.   :yes:   After a few years my truck started cutting off intermittently, and after troubleshooting it turned the Unichip was causing it. It would run fine bypassed, but when the bypass plug was pulled the cutoffs soon started again.

I sent the Unichip back to the factory in WA for testing, and a tech I know there retuned it for his BMW. It worked great for him for three months. He sent it back to me with a milder Jeep 4.0 map loaded in and I plugged the Unichip back in. Soon the random cutouts started again. I got sick of it, put it up on Ebay, and sold it to a guy in Brazil. He's still running it today on his Wrangler and loves it.  :dunno:

You can tell the Unichip is gone on the stroker, but not so much under 3K RPM. But over that is when the tune really kicks in. I'm older now, and don't drive as stupidly? as I used to, so I really don't miss it. Oddly enough, the Unichip gave me about a 2MPG mileage improvement.

The Hesco 10* timing advance CPS was developed to go with a lumpy big-lift cam Hesco sells, but according to them the CPS works well in some stroker engines too. I've got a spare CPS I'm going to modify one of these days so I can slide the pickup on the mounting bracket and adjust timing incrementally to see what works best. Altering the CPS pulses' delay to the ECU is the only practical way you can change the 4.0's ignition timing. Rotating the distributor only changes injector pulse timing.

As you know, the 96 was the in-between year for OBD1 and OBD2, and uses pieces from both systems. The MAP sensors are the same for 91-96, except the 96 is throttle body mounted and is the one I use on my OBD1 engine. The 91-99 distributors are the same except for the sync sensor pickup location; I use a 96 distributor.  Also the 91-96 CPS's are the same and just use different connectors. 1997 was the year the full OBD2 system was fully utilized. I can use my Actron reader/analyzer to read and reset fault codes and also run test programs just like you can with OBD2 readers/analyzers. So I have no need for OBD2 since it's pretty easy to vary the tuning inputs to the ECU that matter (including timing) with OBD1. But as far as I know, OBD1 ECUs can't be re-flashed. Anyone know?

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John, Hesco has a CPS for OBD1 (unadvertised) that will give up to 10* advance. You just have to solder the proper connector on from your old CPS.

 

Does that CPS "look" like a factory unit? or is it a custom kind of bracket that relocates the physical location of the sensor a few CM?

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