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Want to convert 88' to Carb & Aftermarket ignition

ianrw

NAXJA Forum User
Hi - Been a good 18months off this list.. and im back needing sound advice.

I've had my 88 XJ for 6 years and had excellenet use of it all over South Africa, Namibia and Botswana.. but about 8 months back had the motor and diff and various bits and pieces overhauled.
Have not driven the car since due to continuous electrical / electronic issues and to top it all just been told that the control module (computer) has blown and would need a new one... enough already!

I just want to dump everything related to the fuel infection system, throttle body and ignition and convert to a carburator and aftermarket electronic ignition to give me a simple, reliable pwerful towing car i can fix in the middel of nowhere if needed.

Can anyone recommened a good kit to do this and what is included/excluded, and failing availability of kits - what is recommended & where to get it

This is my last stand else im going to break it up and sell her off for spares....or dump it over a cliff :)

Desperado...
 
(1) I'm not certain how similar the ports in the head are, but you might look at the intake manifold from any pre-1991 Wrangler, with the 4.2L engine. Here in the U.S. those were carbureted.

(2) Track down Clifford Performance & Research in California. They offer a variety of intake systems and carburetors for 6-cylinder engines, and they specialize in AMC products.
 
Just to be the devils advocate here many people with the carburated 4.2 L in other jeeps have tried to do the opposit of what you want. i.e. drop the carb in favor of the FI. this is such a popular idea that Jeep, or Mopar has built a complete kit to put FI on the 4.2 as well as Howel, and Holley just to rid themselves of the carb. I have been to Tanzania, and I understand your attraction to something simple, and easy to fix but how long has the computer, etc held up on your jeep in the harshest of environments. It seems reasonable to me that it might fail after a hard life, and deserves to be given another chance. I have driven carburated 4.2s, and FI4.0Ls, and there is no question that the 4.0LFI is more reliable, more powerful, and easier to fix/diagnose. Thats why you might see an older cherokee in africa, and not an older YJ. Infact if any wranglers that were sold in SA the same year as your XJ I would bet they have long since been sent to the junk yard just because they came with a carburated 4.2L.
I think if your heart is set on loosing the FI the best bet is an intake from Clifford, as the ports on the 4.2 intake wont match up with the 4.0L head exactly, and ma caues more problems.
Id Keep the FI. it will make your life easier, and probably be chaeaper than going to a carb.
 
Tx for the input guys.. I wholeheartdly agree and if i was stateside wouldnt hesitate to keep it stock.
We (me?) are unfortunate that all Jeeps pre 96 are deemed grey imports in SA(mine also being a LHD imported from Canada sometime in 90) so we got little or no interest from our Chrysler/Jeep dealers here and the cost of importing stuff is truly bizarre.

Some more bad news too from my Autolecky today and looking like the wiring is shot in several places due to age and the constant pounding and no doubt several hacks in the bush to get things ticking again.
200k miles of pretty hard work cannot be faulted, thats a fact, (incl towing loaded trailers and my aircraft all over the place).
I certainly wouldnt consider anything else

Im going to look into Clifford option and see where it leads. Was kinda hoping though that the tooth fairy was going to leave me a new (prefer older) Jeep under my pillow :)
 
Ian -
Call me cranky, but if I wanted rock-solid reliability, I'd build it. Anything you get from the factory is a compromise between Engineering (Let's build something solid) and Accounting (Don't spend too much!) Left up to me, I'd fire accounting from any engineering decisions, but that's just me...

As a result, I've long thought that reliability - like performance - can be built but not bought. If you've got wiring issues, that's the place to start (as far as a replacement ECM, you can probably get one from someone here - I've not got one, or I'd help you out.

I don't know how bent you are on keeping the XJ, so adjust this as you see fit.

First - Painless Performance (www.painlessperformance.com) makes what is pretty much held as the best automotive wiring in the business - I'd start with one of their 18-ckt "Universal" kits, and I'd ask for two modifications: 1) extra-long wiring; and 2) Leave the wiring unconnected from the fuze block, using one of their "replacement" units. This will allow you to rerelocate the thing to wherever you want.

Second, check out Allied Electronics (www.alliedelec.com) - I'm pretty sure they have a distributor somewhere near you, but I can't find their catalogue right now to make sure. They've got about the best prices (in US$) on Amphenol and other "environmental" connectors I've tracked down, and that's what I like to use for any bulkhead pass-through connections and anything exposed to harsh conditions. Use these to pass anything through sheetmetal, and for any subharness connections.

Now, for replacing any OEM connections (they're pretty much all Delco Weatherpack, with the occasional Deustch or Bosch connection) you can give MSD Ignition a shout (www.msdignition.com) They've got pretty much anything you'll need there, and it's as good as - but less expensive than - Painless.

For an ignition upgrade, MSD has stuff that will (I need to confirm!) talk to RENIX controls. Ask about MSD P/N 8813, which is billed as a adapter for 2.5/4.0 Jeep with "Integrated Ignition Module/Coil Assembly" - and I know Chryco used the coil on the side of the block until they went with DIS/CPP for 1999. This harness looks like it will interface RENIX controls to an MSD 6 or 6-Offroad, both of which should suit your purposes.

Lastly, I'd rebuild the OEM fuel injection, rather than stepping backwards to a carburettor - and that's saying a lot, since I've never been a huge fan of fuel injection. However, the RENIX system is probably the most adaptable and rock-solid of the lot, and I've grown attached to it. (Meanwhile, I've never really cared for ChryCo, and I'm sure it hasn't much improved under DCx.)

Of course, this could all be taken with a grain of salt, since I haven't written the "Worldwide Suppliers" part of my book yet - most of the interest I've gotten has been domestic. That doesn't mean I won't write it - I just haven't had enough interest to bother. I am always willing to be convinced, tho...

I did get your PM - consider this the reply. I just thought this was a subject that really should have been covered in Open Forum - I've been tossing a lot of ideas like this around lately, and something tells me that you and I aren't the only ones who might think along these lines...

5-90

[ADD] How'd you pop a RENIX EC? I've been beginning to think that was nearly impossible.... [/ADD]
 
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I'm sure we could come up with a computer for you cheap on this board. Is yours an auto or a manual? I have one for a 88 4.0L w/manual tranny. You pay the shipping and duty and it's yours. I routinely ship world wide so its not a big issue for me to ship. If you need a copy of the wiring manual, I can get mine scanned if you need it. I have the EFI manual in pdf already.

Grant on this list is from SA and his parents still live there. He may have an idea where to score XJ parts down there as well.
 
Stuck in Southern Africa?

You may want to search for a wrecked CJ Jeep with a 258ci six as a parts donor (any AMC inline six parts donor).

The RENIX MPI cam position sensor style distributor can be replaced with an earlier AMC distributor (or a General Motors inline six model after swapping the cam gear). The inductive pickup of the later CJ 258ci distributor works very well, but do not use the AMC electronic control box (bypass the box or buy a MSD unit). The 70's vintage AMC point-contact distributors are inferior to the late AMC and GM units (but use what you can find, and upgrade with a Pertronix inductive pickup kit if needed). Wire the distributor like an old fashion point ignition, with the coil powered off the switched ignition hot. The RENIX E-coil can be reused (I cannot remember if the controller under the coil has to be bypassed).

The late 258 intake manifold will bolt to the RENIX head without leaks. You may need to modify the accessory mounts (the power steering pump mount) and add washers in addition to the cone washer to level out the mounting of the 258 intake and 4.0L exhaust manifold flanges. The good late model intake is a 2-barrel manifold, but the factory Carter BDD carb is junk. The junkyard options for a carb may be limited in SA. Ford (and Bedford/Holden/GM) Holley-Weber style replacements work well (quite like a vacuum secondary downdraft Weber from a mid-size 70's Ford sedan), or a mid-70's Ford truck 2-barrel (autolite 2100 series). These carbs will need an adaptor plate to bolt on the AMC manifold (IIRC).

Find a good carb, and then find or machine an adaptor to make it fit, even if you have to machine a carb adaptor to fit the factory RENIX throttle body manifold (the RENIX manifold injector holes and EGR can be plugged).

Clifford Research has manifolds that are set up for a 390 cfm 4-barrel Holly, and can be adapted to a 2-barrel. The power gains over the later factory 2-barrel manifold and a quality carb (like a Holly-Weber 38/38 with mechanical linkage) is debatable.

You will also need a fuel pressure regulator to reduce the 39-45 psi (3-bar) off the in-tank pump to a carb friendly 6-12 psi (1/2 to 1 bar). Modify the RENIX 39 psi fuel rail & regulator to maintain the fuel return system and tee a static port fuel supply to the low pressure regulator that feeds the carb.

Good luck on the conversion. Adapting a carb and fuel supply is the more obvious difficult part of the process, but the engine accessory mounts may present a problem (you may need to swap over the CJ mounts and pump).
 
Im getting the drift from these posts - and I can see i need to do more R before I start the D.
So be it... As always the info provided by u gents here invaluable and highly appreciated.

'Donga-Dan'
 
A bit more tantalizing info....
The IC board in the EC is definately burned and the autolecky said its is on the part of the board called the 'OUTPUT STAGE' that controls the Injectors (they all remain fully open) and its was probably caused because of a short in the injector harness (he wasnt certain).... if this helps to shed any light on the subject

If I stick with the electronics (the convert does look a little daunting at this stage), looks like I will need a new ECU and probably some of the engine side wiring harness at least

Heres the info I found on/in the EC unit:
On the Box: Bendix (8825) EF8953005406 Made in France S101140202B
On one of the circuit board chips: FENIX2 B01060
On the circuit board itself: 140x02 1673
Cars Vin Number/details: 1JCMR782XJT248471 4l Auto LHD

so if anyone has one of the these...... :)
Q: Is Renix same as Bendix?

Thx
 
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