Renix or HO, that's the question... Advice needed

[knever3]

So with the stroker out again and going back to the engine builder to see what's making noise I have a few decisions to make.

 

As some of you know it's a '87 Renix with a stroker with a '99 intake and fuel rail.

 

I have had a heck of a time finding a Renix flexplate that will work so I bought the Hesco relocation kit with crank damper so I can run just any flexplate.

 

Now is the time to decide if it's worth it to ditch the Renix stuff and go HO.

 

 

 

Less problamatic with more accurate gauges (mine are all off and I can't trust them for anything)

Updated parts so finding them will be easier.

Expensive and time consuming

 

I would have to change all my sensors, the gauge cluster, the fuel pump and all wiring.  Not an overnight task, but the entire drivetrain is already out.  Speaking of drivetrain I would like to go with something newer, getting away from the 21 spline stuff and going to a 231 instead of the 242 because the Novak cable shifter doesn't work with it.

 

 

There are a ton of things to do, basically find another donor and strip everything and make some stuff, relocate everything under the hood etc.

 

Question is, would you do it?? and why?  Make me a believer, to be honest I am not impressed with Renix anymore.

[AeroNautical]

While we wait for cruiser to chime in, I'd say if the option is available, and your willing to do the work, go for HO. OBD2, all the benefits you list, easier to find parts for, that whopping 8HP over the renix. I love my renix to death, but at the same time it's killing me. Granted it's my fault after I hydrolocked it, but damn if it's not one thing it's another. 

[HOrnbrod]

That's a no-brainer for all the reasons you mentioned and many more. Go HO, OBD1 is fine and a much easier conversion. If you're a masochist, stay Renix and deal with a new adventure everytime you start it up. If it starts. .

[fiatslug87]

[HOrnbrod]

Hey Don, don't hate.

 

I've had them Mike. Never again. Don't need the aggravation anymore. It's a shame MJs were deprived until 1991 when the MJ had low production numbers and there are not many stockers around anymore. But it's not too hard to convert to OBD1, thanks to the many XJ survivors. 

[glundblad]

Mine is very solid.  Bulletproof in fact.  But I don't think I would trust it enough to stroke it.

[Jeepman]

My first conversion of my MJ was switching from Renix to OBD and the change was well worth R and that was like 8 years ago however my recent conversion to OBDII was the best so I'd say concert to the OBD for sure.

[AeroNautical]

 

Hey Don, don't hate.

 

 But it's not too hard to convert to OBD1, thanks to the many XJ survivors. 

 

I thought the Renix units were OBD1 and the HO OBD2? My mistake. 

[Eagle]

I have had a heck of a time finding a Renix flexplate that will work so I bought the Hesco relocation kit with crank damper so I can run just any flexplate.

 

Now is the time to decide if it's worth it to ditch the Renix stuff and go HO.

I don't think now is the time to decide between Renix and HO. Thew time to decide would have been before you bought the HESCO relocation kit. The size, shape and distribution of the notches and bumps on the flex plates are different between the Renix and the HO because the CPS for each operates on a different principle and generates a different type of signal. The relocation kit would have to be configured similarly. The problem is, the information on HESCO's web site doesn't say if the kit is Renix or HO. Before making a decision, I'd suggest contacting HESCO to find out.

 

My guess is that, since these kits were offered by HESCO before the HO came to exist, the relocation kit is going to be a Renix-only affair.

[onlyinajeep726]

I have a stroked HO in my '88 Renix XJ.  All the electronics are Renix, but all the bolt on accessories are HO with exception of the alternator.  It was a lot of work but it works.  Now, if I ever had to do it again, I'd seek out an OBD1 at the least.

[jpnjim]

Renix benefits;

1)knock sensor = more advanced timing that retards ignition when it 'hears' a knock

2)no check engine light

only a benefit if they do emissions testing for inspection.

nothing worse than the CEL coming on, or the car throwing a random code, or "systems not ready" because your battery died the day before you need an inspection sticker 

3)voltage regulator is NOT part of the engines computer.

HO's incorporate them together,

I don't know if any decent work arounds have been figured out yet,

but plenty of people have had to buy new Mopar ECM's because the voltage regulator inside theirs failed

4)Yours is already a Renix

= you can keep the GM alternator & brackets you already have

you don't have to rerun any wiring, mount the HO computer change the flywheel/flexplate (tho I guess that's not applicable in this case), gauges, o2 sensor, add a speedo sensor, etc etc.

[jpnjim]

HO benefits;

1)It stores codes, so you can put a code reader on it to see what's wrong with the system.

2)HO's came with all kinds of better parts,

better head, intake, injectors, throttle body,eliminated EGR, better header,

and the OBDI system is already set up to run everything

= you don't have to cobble together a conversion TPS to use the intake & TB.

& you don't have to *hope* your Renix PCM *likes* the bigger injectors & lack of EGR

3)parts availability

4)simplicity (once its converted)

[shelbyluvv]

I can't stand the Renix engine management. There is a reason why my trucks are OBD-I and OBD-II. They flat out work better and are more user friendly to me. Some like the Renix system. I'm just not one of them.

[mnkyboy]

I've had both and don't mind either.

 

When i swapped my MJ over I was suprised how much simpler the later wiring is, I think I removed a million miles of wiring from my truck.

[91Pioneer]

I've owned both and if I had to pick, I'd pick HO just for the reliability aspect. My stock HO seems to idle smoother and start better than the Renix. Either one gets the job done though :)

[yxmj]

I have both right now, for quite some time...IMHO the Renis is a great piece of engineering.......if you leave it alone....it does not take to mods......if you want to mod and put on improvements, to get max out of the 242 platform....start with a HO as your base.

 

That being said I have a stone stock low mile 88 XJ Laredo that will snap your head back when you put your foot into it......

[Brickmiata]

There really isn't anything too complex about the renix system.  I've always found OBD codes to be inaccurate and annoying anyway.  For a daily driver with no mods, I'd rather have a well cared for renix. 

[knever3]

The more I think about it I am in WAY too deep.  I have these parts for the Renix system on my '94 block, '96 ported head and '99 intake.

 

Brand new 100A Bosch alternator

Hesco TPS adapter

Hesco Crank Damper CPS relocation kit

 

 

So if I were to go with an HO upgrade I would have to buy a new alternator and brackets, A/C compressor bracket etc.

[Eagle]

The more I think about it I am in WAY too deep.  I have these parts for the Renix system on my '94 block, '96 ported head and '99 intake.

 

Brand new 100A Bosch alternator

Hesco TPS adapter

Hesco Crank Damper CPS relocation kit

 

 

So if I were to go with an HO upgrade I would have to buy a new alternator and brackets, A/C compressor bracket etc.

You would also have to give up your HESCO CPS relocation kit, I believe.

[knever3]

 

I have had a heck of a time finding a Renix flexplate that will work so I bought the Hesco relocation kit with crank damper so I can run just any flexplate.

 

Now is the time to decide if it's worth it to ditch the Renix stuff and go HO.

I don't think now is the time to decide between Renix and HO. Thew time to decide would have been before you bought the HESCO relocation kit. The size, shape and distribution of the notches and bumps on the flex plates are different between the Renix and the HO because the CPS for each operates on a different principle and generates a different type of signal. The relocation kit would have to be configured similarly. The problem is, the information on HESCO's web site doesn't say if the kit is Renix or HO. Before making a decision, I'd suggest contacting HESCO to find out.

 

My guess is that, since these kits were offered by HESCO before the HO came to exist, the relocation kit is going to be a Renix-only affair.

 

 

Yeah I already bought the kit but haven't installed it.  Time to make a decision...

[HOrnbrod]

 

I have had a heck of a time finding a Renix flexplate that will work so I bought the Hesco relocation kit with crank damper so I can run just any flexplate.

 

Now is the time to decide if it's worth it to ditch the Renix stuff and go HO.

I don't think now is the time to decide between Renix and HO. Thew time to decide would have been before you bought the HESCO relocation kit. The size, shape and distribution of the notches and bumps on the flex plates are different between the Renix and the HO because the CPS for each operates on a different principle and generates a different type of signal. The relocation kit would have to be configured similarly. The problem is, the information on HESCO's web site doesn't say if the kit is Renix or HO. Before making a decision, I'd suggest contacting HESCO to find out.

 

My guess is that, since these kits were offered by HESCO before the HO came to exist, the relocation kit is going to be a Renix-only affair.

 

 

Hesco makes separate CPS relocation kits for both the 87-90 Renix and 91-04 4.0 engines. Assume you have the Renix kit knever?

[Eagle]

Hesco makes separate CPS relocation kits for both the 87-90 Renix and 91-04 4.0 engines. Assume you have the Renix kit knever?

Don, is that shown on their web site? I looked, and I didn't see any reference to different kits.

[HOrnbrod]

Sure is, about half way down on THIS page.

 

87-90 p/n HES8790ED

91-04 p/n HES9199ED

[Guest]

I'm not going to parrot everything everyone else has said about the ODBI vs. Renix debacle; instead, I would look at how much time, effort, and money you have invested into the project as of this moment. Both systems have their advantages and disadvantages, but I would look at how much getting an ODBI drivetrain + accessories is going to cost as compared to what you've spent, and are looking at spending to finish up using the Renix equipment you have now. 

 

Still, I'll give you props; trying to get the most out of the Renix setup is an admirable feat in and of itself. :cheers:

[A-man930]

Megasquirt.

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