Renix

[grouch]

I'm new.................What is a Renix?

[87MJTIM]

In the late 80's, Jeep partnered with French auto maker Renault.  Jeep got Renault to build its fuel injection system in the 4.2 6 Cyl.

 

Renault worked with Bendix to build the system

 

RENault + BendIX = RENIX

[Ωhm]

It's a title given to a Engine Control Unit (ECU).

[grouch]

Thanks...........Some of ya got a French flair under the hood and I get a GM V6 dog with a carburetor.  The good thing is at least I can work on it.

[FrankTheDog]

I bet even the renix fi is easier to work on than a 2.8’s carb. I never really had to work on any of my 4.0’s fuel injection of any flavor. They are super easy to work on.

[DirtyComanche]

The Renix represents the pinnacle of simple EFI.  It does everything it needs to, and nothing it doesn't.

 

It's too bad we can't get into the ROM and play with things a little more.

[Pete M]

 

 

[Eagle]

Carburetors  are basically pretty simple devices. The problems arise when you take a simple device that has been working just fine for decades, and try to overlay computer controls on it. There used to be a guy here in Connectucut who went by the name of Mr. Carburetor. He did carb work for many of the stock car teams who used to race at the old Riverside Park speedway in Agawam, Massachusetts. I once took him a carb from an XJ 2.6. He got it running, but he advised me that the best thing I could do would be to discard that thing and buy a "real" carburetor.

 

[derf]

Carburetors have a very difficult job to do.  They need to properly meter air and fuel over a really wide variety of conditions.  By the 80's they had gone about as far as they could.  The fundamental problem is that carburetors just don't offer the fine control over air/fuel that's needed.  There's just no way to account for everything going on that affects your mixture.

 

The attempts to add computer control was a patch while they worked on their fuel injection systems.  And they are, without exception, a disaster in the long run.  I won't keep a computer controlled carburetor on any vehicle that I own.  They're just not worth the hassle.

 

My old Grand Wagoneer ran great with a Truck Avenger carburetor on the 360.  Did everything I wanted it to.  The off camber capability of that carb was great.  One I had it dialed in, it actually got relatively good fuel mileage for a brick on wheels with an out-dated V8 running a carburetor (mid teens).  It started up and ran great around town and on the trails. 

 

But it was still a carburetor. 

 

Compared to fuel injection, even the best of carburetors are cold blooded.  And taking it from Texas (where I lived at the time) to the mountains meant I had to rejet somewhere on the trip.  Sometimes even 2 or 3 times.  If it sat for a while and the fuel bowls dried up, I'd have to crank for a while for the pump to get fresh fuel into it.  And then the emissions issues compared to fuel injection are all there (if you care about that).  A car with a carburetor pollutes more while sitting in the driveway than a modern fuel injected car does while driving down the road.  Those fuel bowls, even with evap systems, still evaporate raw gas into the atmosphere.  And then there's the fact that carburetors require regular maintenance to stay in top running condition.  Fuel injection may need some work from time to time but nothing like a carburetor.  You can run a FI car for years without touching anything.  A carburetor requires minor adjustment at least once a year, if not more often.  Hell, some need to be tweaked a couple times a year to deal with the weather changes.

 

For me, getting a good fuel injection system with aftermarket support is the answer.  The computer can just naturally do things that a carburetor can't.  Depending on the system, it can compensate for altitude changes.  It's way less cold blooded than a carburetor.  You get better fuel economy across the board (within reason).  You can darn near run the engine upside down if you could get the oil system to keep working so they are great off road.   Given the variety of aftermarket fuel injection systems out there, along with factory donors as options for a swap, there's just no good reason to run a carburetor in anything any more.  Unless you're driving a nostalgic vehicle or you just want to.