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Renix/HO mashup questions (fuel pressure)

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I'm assuming you've not got it running yet and if so I've got a couple questions:

Does the 0331 head use ignition coil packs? If so, how will that work with Renix?

 

Since you're using the 0331 head, why not use the high-flow 0331 "horseshoe" intake?

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I have a quick question for this thread, even though its pretty old!
 

My Manche has an '01 HO swap into it, electronics and all. I have an XJ tank, but I'd rather reuse the original tank. The HO fuel rail only has one fuel line running to and from the fuel tank, while the old MJ renix tank has both a fuel sending and fuel return line port on the sending unit(fuel tank side).

 

So is it wrong to plug the fuel return line? (I feel it is 100% the wrong choice).

If I shouldn't do that, how can I fix this issue? Or am I stuck, and have to use the XJ tank? I saw one posting about cutting into the top of the tank and creating your own mount spot for the XJ sending unit, and I'm not comfortable doing that.

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The ‘01 XJ fuel pump assy. has a built in pressure regulator.  You will need that to work with the fuel rail from an ‘01.

 

The gauge sender is different, of course, on the MJ fuel gauges😢

 

The perfect setup would be to somehow mount MJ fuel sender onto your XJ pump assy., and then mount that whole thing into you MJ tank.  
 

The last part is the toughest, and I suspect that’s why most guys wind up putting in a tank compatible with the late XJ style pump assembly.

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On 3/27/2018 at 6:29 AM, Kickin’Chicken said:

Does the 0331 head use ignition coil packs? If so, how will that work with Renix?

 

the 0331 uses coil packs and no, it doesn´t work with renix...

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Ok.... as I’m new to the Comanche/ Cherokee thing.... all 11 of my other jeeps were from 43-68. What is RENIX and does my 87 2.5 manual Comanche have this?  

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3 hours ago, Comanche1 said:

Ok.... as I’m new to the Comanche/ Cherokee thing.... all 11 of my other jeeps were from 43-68. What is RENIX and does my 87 2.5 manual Comanche have this?  

 

RENIX was the partnering of Renault and Bendix.  In the 80s, AMC was partially owned by Renault.  AMC gave the Jeep 4.2/258 engine to Renault to "fix it up" with fuel injection.  Thus, the RENIX fuel injection system.  Some Jeepers swear by it; others swear at it.

 

I believe yours is a RENIX. 

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11 minutes ago, 87MJTIM said:

 

RENIX was the partnering of Renault and Bendix.  In the 80s, AMC was partially owned by Renault.  AMC gave the Jeep 4.2/258 engine to Renault to "fix it up" with fuel injection.  Thus, the RENIX fuel injection system.  Some Jeepers swear by it; others swear at it.

 

I believe yours is a RENIX. 

Thanks. So the 2.5 throttle body is Renix. 

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I am no expert on the 2.5.  I believe it has much of the computer electronics of RENIX.

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2.5L is TBI Renix. They were the first of the two Jeep engines to get this computer system. The other being the 4.0L with Renix MPFI.

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The 4.0 has port fuel injection and the 2.5 in that year would have throttle body injection.  The biggest difference is where the injectors sit.  In the 4.0, there is one fuel injector for each cylinder, stuck into each intake manifold runner right before it enters the head.  In the 2.5 you have only one injector (or maybe two) sitting on top of the throttle body instead.  It's like they took a carburetor, cut out the fuel bowl and venturies and attached a fuel injector or two on top of the throttle plate.

 

Both systems are computer controlled and have things like oxygen senors, pressure or airflow sensors (depending on how the computer is set up), throttle position sensors, idle air control valves, etc.  The parts may not interchange, of course, with each having a unique part to accomplish the same task.

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