Crapping Carb Scrapping
I have just finished reading "The $1,035 YJ" (April '09). I have owned a '92, '93, '95, and '01 Wrangler. Currently, I am looking at a '89 Wrangler to purchase. I have never dealt with a carburetor before, but fuel-injection I understand! What did you do with the carb in your '89 Jeep?David SchmidtVia e-mail
All four-cylinder YJs were fuel-injected from the factory. The engine and induction in my Jeep are stock. From '87-'90 the 2.5L had a TBI (throttle body injection) until it switched to the MPI (multi port injection) in '91.
The six-cylinder YJs were a mixed bag. The '87-'90 vehicles got the carbureted 4.2L (basically the same setup as the older CJs), while only the '91-and-later got the MPI 4.0L six-cylinder.
If the Jeep you're looking at has the 4.2L, I'd strongly suggest scrapping the factory 2bbl. The cheapest upgrade is to replace it with a Motorcraft 2100 2bbl off of a Ford six-cylinder or small V-8 engine. The Motorcraft carb doesn't bolt straight up to the 4.2L manifold, so you'll need to use a PN 2086 small-to-large 2bbl adapter from Trans Dapt (tdperformance.com).
Guys have also swapped a 4.0L head and factory H.O. injection to the 4.2L block, but in my opinion it's a problematic procedure when you consider the ease of a Howell EFI system (howell-efi.com).The company's YJ kit, PN CA/YJ258 is 50-state emission-legal and offers great drivability.
Avenger Injection
Several months back you had article about how Cappa put 100,000 miles on an Avenger supercharger installed in Jp's '01 4.0L TJ. Did he have to reprogram his ECM? I have an '04 TJ with the 4.0L and automatic transmission and am looking into getting an Avenger supercharger. I had my heart set on a Kenne Bell, but they are no longer handling the chip or the supercharger for the 4.0L.John VegasLarose, Lousiana
John Cappa replies: Just 24lb injectors with no computer change.
Wiring Gremlins
I have an '03 Wrangler Sahara with a 4.0L, NV3550 five-speed, and A/C with 90,000 miles on the odometer. The blower stopped operating at the first two settings awhile ago. However, it still works on the two highest settings, so I have been putting up with it even though it is a pain sometimes. Do you have information that will help me replace the switch? I can take parts off and replace them, but troubleshooting is a problem. The dealer told me the resistor has burned out at the lower speeds. Also, is there a fix to do so this will not happen again?Scott FairgrieveBarrington, Illinois
Pete Trasborg replies: The resistor is accessible from the passenger's foot well up under the dash. If it is only the resistor going out, then just replace it. If you use your HVAC a lot-with your winters, I would suspect this is the case-the resistor is something that can die. I've replaced scads of them over the years.
Pull your dash apart and look at the electrical connections on the back of the HVAC control panel at both the speed selector switch and the "range" selector switch. If you see any evidence of melting plastic or connectors there you'll need to take additional steps. Either blower motor replacement or adding relays could be in your future if those connections are starting to melt.
Resurrection
I want to ask some advice of professional Jeeper dudes. I purchased an '88 Wrangler that was beat to death and I am in the process of rebuilding it to be a fun weekend cruiser. The motor did not run, the transmission was slipping and leaking, and so on. I bought it because it was cheap and had a lift, wheels, tires, and other goodies. I've rebuilt the tranny, the motor is running good except for the carb, and the Jeep now has new 36x15.50-15 Dick Cepek Mud Country tires on 15x10 rims. It has approximately 4 inches of suspension lift from Superlift springs with heavy-duty shackles and a 2-inch body lift.
As for the stock 258, I cut out restrictors in the intake manifold and it runs a stock exhaust manifold with an aftermarket muffler. I neutered the computer and will have a little hotter coil installed. I removed all smog crap and unplugged the carb, which I am looking to replace. I have been looking at Howell injection systems and that is what everyone is recommending. I am an old hot rod guy and this is my first Jeep, so there is a part of me that wants to install an Offenhauser intake and header and a Holley 470cfm Truck Avenger. Holley says its Avenger carbs can crawl just like injection. I think I can make the old six come alive and build some horsepower for less than the injection system. But what about linkage and how well does the Holley work on the 258 engine? Spending one-third of the whole $5,000 Jeep fund on fuel injection is hard to swallow.
Also, I have a Ford 8.8 rear axle with 4.10 gears and an ARB locker. What do I need for spacers to get Ford 8.8 axle to line up? I think it is about 1 1/4 inches narrower. I have a later-model Dana 30 with 4.10s to install up front.Steve BurgerVia e-mail
Use the Spidertrax 1.25-inch spacers on the Ford 8.8 to keep the tires out of the rear inner fenders.
Holley is being a bit optimistic in their evaluation of the Truck Avenger. It's not as good as fuel-injection, but it is one of the best off-road carbs. Personally, I like the Rochester Q-jet a little better off-road. You could probably find one on a Chevy 305 that wouldn't totally flood your engine, but the Holley 470 Truck Avenger is a better match for your 258 cfm-wise.
Injection opens up a whole new can of worms with electronics, fuel pumps, sensors, and so on. Although it's far superior to any carburetor, you can get good performance from a Truck Avenger or a junkyard Motorcraft 2100 2bbl. Pretty much any Ford car or truck from the late '70s through the '80s should have the 2bbl Motorcraft. Lower the floats a bit and they do quite well off-road. Trans-Dapt makes an adapter that will allow the big-pattern Motorcraft 2bbl to mount in place of your small-pattern 2bbl on your factory manifold under PN 2065.
Personally, I'd do the Motorcraft carb because you'd only be into it for $50 or so. Then, if you need more power down the road, upgrade to injection when funds permit. The Holley is a great carb, but it's a bit much for a 258 and in my opinion is better suited to a stock AMC 304, Ford 302, or other similarly-sized V-8.
Light 'er Up
In the November '08 issue, "Fireproof 4.0L," you list a PN 02801580444, then you list another of PN4L3Z9F593CA.
I Googled the first part number with no results and found the second part number at several sites. Is the first one a misprint?
Thanks for the great article because I am having this same issue with my '89 Cherokee!Pat CalahanElma, Washington