Saturday, October 15, 2016

Fuel Pump Problems

The electric fuel pump stopped again! This time it happened three miles from home after an hour drive back from Colorado Springs on a warm fall day (80F). The Jeep acted like it was running out of gas. When I tried to restart it, the fuel pump did not come on like it normally does. It came back on after the Jeep sat for about 10 minutes.

These symptoms occurred a few other times. Once on the nightmare trip back from Moab this past spring, but that's a long story for another day. Another time on the Bunce School Road trail (2015?), and on the way back from Boulder in June 2014 both during the late afternoon and at night.

The fuel pump doesn't always cut out on long trips and/or warm days. I had no problems on the way to Ouray and back last year, or on the way out to Moab, or to Colorado Springs, or on any other drive or trail that I've been on in the last three years since the problem started appearing.

I did notice the last couple times this happened that the ECM box in the passenger cabin, and the relays in the engine bay, were hot, while the fuel pump itself was barely warm. However, on the way back from Moab, I noticed this and tried swapping relays and ECMs to no avail. This time, I happened to have my laptop running TunerPro with ALDL connected and the ECM was reporting "OK" status for the fuel pump relay.

This is one of those very rare, unpredictable, intermittent problems that is wickedly hard to troubleshoot... 

Meanwhile I'm still trying to figure out how to get the ECM tuned to run well and also pass emissions. I've also got a (new to me) 1911 Officer-size pistol that has been misbehaving. 

Don't get me wrong, I love troubleshooting hard problems, but sometimes when problems pile up it can be overwhelming.

Tuesday, May 3, 2016

Front Door Speaker Install

My Alpine deck and 5" Boston Acoustics should have sounded decent but even for small speakers, they lacked the low end response. Why?

In large part because the OEM speaker installation method leaves much to be desired. 

Speakers are mounted on flimsy sheet metal that partially spans a giant hole in the door. 

To get more out of your FSJ's stereo, read on.

Saturday, April 30, 2016

CB Radio Tips

Hey rubber duck, got yer ears on? Citizen's Band (CB) radio has held its popularity with off-roaders. No license required and a mobile-mounted CB has reliable, sufficient performance for the trail.

Ready to buy a CB system? Read on for some thoughts and experiences...


At wheelin' ranges, any decent antenna should work. Buying used saves money, too. I've run across some great deals along the way. Cruise the Goodwill, 4x4 club swap meets, Craigslist, etc. You might occasionally find a deal on ebay.

I've run: Hustler 17" permanent mount, Larsen permanent mount, cheapie fiberglass bumper mount, and a K40 and K30. They all worked ok but the K40 magmount was the best performer. It hit too many branches, though. I run the Larsen with a spring on the base.

In some cases you may have to tune the antenna to resonate across the CB frequency range. Standing Wave Ratio (SWR) meters measure how much power is transmitted versus reflected back to the radio. You can find low cost vintage SWR meters on ebay.
SWR / Power Meter
A perfect setup has an SWR of 1:1 and will maximize the legally limited 4W of radio power, while anything under 2:1 is acceptable. 

Generally I find that better and/or longer antennas have a lower SWR over a wider range of frequencies than smaller and/or cheaper antennas.

Installation matters. Grounding the radio to the chassis is important for good permanent mount performance. 

Placement in the center of a steel roof maximizes performance in all directions. But it also maximizes branch hits. You need a spring, strong magnet, and/or durable antenna. I prefer permanent mount on the roof with a spring.

You can mount it on the back of the truck (bumper, tire carrier, etc.) where it's more out of the way, with a tradeoff in performance that probably doesn't matter at trail ranges.


You're legal limited to 4W, Amplitude Modulation so radio performance matters very little. And, look around for deals on used CBs. I've gotten lucky a few times. It's more about features, many of which I personally think are a waste of money for four-wheeling. 

Single Side Band is rare to find on the trail and really only good for long distance communication.

Chrome on radios reflects sunlight, blinding you on the trail as your rig moves at various angles.

RF Gain effectively ignores people further away than your 4-wheel group. You can always switch channels, though.

Noise filtering clean up the audio from ignition noise electric fans, etc.

Weather (WX) channel capability would be handy to have.

CH 9/19 switch is less useful than I originally thought.

Public Address (PA) is marginally useful to have if you hook up a PA behind the grille. Can be helpful in communicating with spotter or people walking.

I really like my Uniden 520XL, a small, all-black CB with RF Gain and noise filter, and think it is a great unit for four wheeling. The Uniden 510XL is a budget option lacking RF gain.


This is just a short overview of some thoughts when you go to buy a CB and antenna. For an outstanding set of articles on antennas and how to get the best performance out of your radio, check out the Firestik Library.

Monday, April 25, 2016

FSJ Cowl Vent Screens

If you've owned an FSJ during autumn, you know that the cowl fresh air intake is a magnet for leaves, twigs, and other debris that end up clogging your fresh air vents and drain holes, leaking water into your FSJ and rusting it from the inside out.

Several years ago, I implemented a low cost solution that's easy to install and aesthetically pleasing.

First, remove the vent grill. Lift the engine hood and then remove 7 screws and the windshield washer nozzles and lift out the cowl vent grill. The grill measures about 48" x 6".

A trip to the local home improvement store yielded several viable options. Of those, I selected these plastic gutter screens as one of the lowest cost options. They've held up well for 10 years so far.

Next, use the grille as a pattern and mark on the rain gutter covers. Two are required to cover the entire cowl vent. Position the cover to hide the thick bars of the gutter cover. Measure twice, cut once! 

Gutter screens
Each covers half the cowl vent
Measure twice and mark
Cut, test fit, trim
Then cut out the gutter covers with strong, sharp scissors, metal snips, etc.  Test fit and trim so that the guard is slightly smaller than the grille area. 

Now test fit on the cowl to make sure the guard is not blocking the cowl grill's tabs that fit into slots nearest the windshield. Trim as needed.

Remove four rubber pieces against which the grille rests. Note where they were positioned. You'll put them back on later once the guard is in place, using some adhesive.
Reattach bumpers with adhesive
I used these #8 self-tapping screws
It is easiest to attach the guards directly to the Jeep's body, rather than to the cowl grill. I used #8 self-tapping sheet metal screws with wide, flat phillips heads. Before you start screwing in the screen with these screws, mark locations for the screws where they'll be hidden by the grill.

It works great!
Next, drill/drive in the screws, starting at the center and working outward. I used two screws in the middle, at the edges, and one on either side of the washer arms. That's enough to keep it in place and sufficiently tight against the surface of the intake.

What about the window washer nozzles? You could cut a hole for the stock nozzles which suck by modern standards. And, a little bit of stuff might get into the cowl. You could install modern hood nozzles, but that requires cutting up your hood. I tried this but be sure to measure carefully. Finally, wiper arm nozzles are an option, but may require cutting a small hole in the cowl screen to route the tubing.

The final step is to reinstall the cowl vent grill. Then, no more fall leaves entering your fresh air vents! Hope you find this helpful. I'm very glad I did this mod and wished I'd done it even sooner.

Tuesday, April 19, 2016

Replacing an A727 Reverse Servo

I knew what was wrong with the A-727. The reverse servo piston had cracked.

The Shimniok daddy-daughter Moab trip was coming up at the end of March.

I just had to get my rig back on the road and fast!

Which New Piston?

Unlike the stock, cast material, billet aluminum isn't prone to cracking, making them popular among the Mopar drag race crowd who also prefer 1-piece servos without the stock inner spring that cushions reverse engagement.

But surprise! The Jeep isn't a dragster. Fortunately, Randy J (mrrandyj) sells both 1- and 2-piece piston kits for 727. He's a good guy, easy to work with, and happy to share his considerable knowledge.

Real engineering, the kind that takes obsessive dedication and doesn't fit in a sound bite or ad slogan, is what Randy put into his awesome products.

The kit includes the piston, a new piston spring, and a beefy spring retainer, eliminating all the common reverse servo issues. You reuse the stock pin and inner spring.

Read on for the disassembly and reinstallation...