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My Free Jeep Grand Wagoneer Drives But Nearly Started A Demolition Derby In My Backyard

Illustration for article titled My Free Jeep Grand Wagoneer Drives But Nearly Started A Demolition Derby In My Backyard

Oh boy is today’s wrenching tale a classic DT blunder. My Jeep Grand Wagoneer, which I obtained for free from a generous reader named Tammy, has been giving me hell, with its brakes failing, and its motor refusing to consistently start. Over the past few days, I’ve mended those problems (sort of), and gotten the Jeep to drive under its own power. Then things nearly went off the rails.

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The Grand Wagoneer didn’t run when I got it back in June, which isn’t surprising given that it cost me literally no dollars. As far as I know, the Woodie hasn’t run for the better part of a decade. When I got it home, I changed its oil and fuel pump (the rubber diaphragm inside of them tends to fail), slapped in a new battery, and threw in a new ignition cylinder since I didn’t have the old key.

Unfortunately, the damn thing still wouldn’t start with the key. For some reason, the ignition switch doesn’t activate the starter solenoid, so to get the Jeep running, I have to use a jumper wire between the battery and one side of the starter solenoid to get power to the ignition system, and then I have to momentarily touch the positive battery cable to the far side of the solenoid to crank the starter.

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This worked for a while. In fact, after starting the Jeep for the first time in years, I discovered a mouse nest in my exhaust system:

This was way back in October, and it’s a miracle that someone didn’t call the cops after I created a literal cloud in my yard by burning off all the automatic transmission fluid I’d poured into the cylinders (this was to ensure the piston rings wouldn’t gouge the cylinder walls, since the Jeep hadn’t run in a while).

Illustration for article titled My Free Jeep Grand Wagoneer Drives But Nearly Started A Demolition Derby In My Backyard
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Despite having gotten the Jeep running last fall, as soon as I went to drive the thing, my brake pedal fell to the floor and an entire master cylinder worth of hydraulic fluid poured onto the grass. My brake lines were rusted out.

Fast forward to March and I’d purchased some new front brake lines and prepared to install them:

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,

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Buying pre-formed lines was the easy way to replace my rotted-out lines and it only cost me $70. Still, the job wasn’t that easy, as snaking those hard lines through tight spots between the frame and steering box without kinking them was tricky. Plus, trying to spin the lines into the combination valve without cross-threading something was also tough, and required me to unbolt the valve from the frame.

But in time, I got the new steel tubes installed. Behold:

Illustration for article titled My Free Jeep Grand Wagoneer Drives But Nearly Started A Demolition Derby In My Backyard
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In October, as soon as I got the engine running, the brakes went out. Now, as soon as I’ve fixed the brakes, the engine stopped starting. I spent a while trying to diagnose the issue. I pulled out a spark plug wire, popped on a spare spark plug, grounded the plug against the engine while cranking the motor (again, using the positive battery cable against the starter solenoid) and I did see spark.

If I had spark, fuel (I was using starting fluid) and air, why wasn’t the engine running? After taking a break for a few days, I got back to the Jeep, and ultimately figured out that the problem was the ignition module. I have a few spares sitting around the house, so I plugged one in:

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With that hooked up, the Jeep ran for a few moments on starting fluid. Strangely, I saw no fuel going through the clear fuel filter despite having replaced the pump. Even after I poured a five-gallon Jerry can worth of gas into the Grand Wagoneer’s tank, something was stopping the fuel pump from sucking the go-juice into the motor.

So I yanked the rubber hose leading from the pump to the steel fuel line and noticed it was old and cracked. I attached a new one to the fuel hard line and blew on the other end of the hose, forcing any rust or crud in the lines back into the tank. I then hooked the hose to my fuel pump, cranked the motor, and noticed fuel in the filter:

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Now the engine runs off of its own fuel supply and no longer requires me to spray copious volumes of starting fluid down the carb throat. Just listen to this beauty idle:

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With the Jeep now running on its own and after having bled the front brakes, I yanked the column-mounted automatic shifter into drive and gave the Jeep some gas. The AMC V8 roared as the revs climbed, and the Jeep—with two flat tires—dug its way out of the mud hole its 4,500 pound weight had created in my soft backyard.

I began driving toward the rest of my fleet—specifically my “dream” 1991 Jeep Cherokee five-speed and my much-less-dreamy totaled 2003 Kia Rio. So I let off the gas. But the engine’s revs wouldn’t drop. I stomped my right foot on the brake pedal, but with only the front brakes working and the engine revving hard the Jeep kept progressing, as if on an evil crusade to mangle the rest of my fleet in what would, at least from the outside, look like an absurd demolition derby of shitboxes in quaint and quiet Troy, Michigan.

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Illustration for article titled My Free Jeep Grand Wagoneer Drives But Nearly Started A Demolition Derby In My Backyard

Luckily, I had the wherewithal to quickly force the shifter into Neutral and turn the ignition off well before anything became an issue. Then I fired the Jeep back up—again, I’m doing this from under-hood, since the ignition switch in the steering column won’t activate the starter solenoid—and the Jeep screamed. Revs climbed well beyond what I felt comfortable with, so I disconnected the battery cable.

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The Jeep kept running!

This surprised me. The Jeep was running with no battery connected! (This won’t work at idle, but at high RPM, it apparently does work on older cars). I ran into the cabin and turned the key to the “off” position, tranquilizing the mighty AMC 360.

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I later learned that the throttle return spring (which I had replaced, since the old one had failed—its spring constant was essentially zero; I could stretch it with no effort whatsoever) had fallen off, causing the throttle to remain open even after I let off the gas pedal.

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It’s amazing how something as simple and small as a throttle return spring is the difference between a car that idles beautifully and slows down when you let off the gas and a potential 4,500 pound runaway car. Lesson here is: Pay attention to your damn throttle return springs.

The Jeep will soon be up for sale. It runs (though I think the fan is banging into the shroud, and the flex plate bolts are loose—because there are strange noises happening when that motor is running), stops (again, just the front brakes), and its interior has been mostly cleaned out. It’s a great base for a restoration, I think.

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I just want it out of my yard before it tries to attack another Jeep.

Sr. Technical Editor, Jalopnik. Always interested in hearing from auto engineers—email me. Cars: Willys CJ-2A ('48), Jeep J10 ('85), Jeep Cherokee ('79, '91, '92, '00), Jeep Grand Cherokee 5spd ('94).

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This will be a TL;DR for many of you, but I thought you might enjoy as it is relevant to this story.  Excerpt from my book about personal near-death experiences that I’m writing:

350 HORSEPOWER, DRUM BRAKES, AND NOWHERE TO GO

In the early spring of 2005, I decided to rebuild the carburetor on my 1969 Chrysler 300. It was a run-of-the-mill Holley double-pumper and was quite easy to work on. I replaced the jets, needle valve, cleaned everything, and slapped it back together with new gaskets. It was one of those nice spring days where the sun came out and the pavement was dry for the first time since September, although there was still several feet of snow on the ground. I was antsy to get the old car out and tear around.

I hastily bolted the huge carburetor onto the mighty 440 cubic inch V8. I leaned down, twisted the key, and the old engine roared to life. You may recall the episode of “The Simpsons” where Homer designed his own car. One of his requirements was that the sound from his engine would make people think the world’s coming to an end. This was one such car. I would regularly set off car alarms as I idled through the student parking lot at college. Aside from striking fear into the hearts of Honda and Subaru owners, this car only excelled at one other thing: going really fucking fast. It was running tip top as I had cleaned the ignition points earlier in the day. All systems were ‘go’ for some tire-frying exercises.

I fastened my lap belt and yanked the transmission into Drive. I set out on southbound M-26, going easy as I was still in town. I neared the light at the edge of town just as it was turning yellow. Beyond lay a nice long stretch of fairly straight two-lane highway. I patiently waited for the signal to turn and a couple of other cars pulled up behind me. The guy behind me pulled right up to my bumper, perhaps trying to egg me on... I didn’t much care because he wouldn’t be crawling up my ass for long. If I had only known what was to come…

The light turned green and I planted my right foot. The enormous BF Goodrich T/A tires churned and a cloud of smoke emerged from the back of the 4300 lb. car as it hooked up and launched. Man, this fucking thing was hot! Why didn’t I do the carb earlier?! This car accelerated so hard that the windshield washer fluid would pee out of the nozzles just from the inertia of the liquid in the lines, fighting to keep its place in space and time as the car bolted forward. I kept my foot planted as it wound out 1st, shifting to 2nd gear at 58mph, right on schedule. That fucker behind me was lagging by 100 yards. See ya!

As the I approached 80, I figured that I had learned what I needed to know and decided to let up. The 2nd to 3rd shift generally happened somewhere north of 105mph at full throttle and I didn’t need to go there. I lifted my foot, and absolutely nothing happened. The pedal was still down on the floor and I continued to accelerate. What the?! Fuck! Fuck! I stomped on the pedal, hoping to dislodge whatever was sticking it down. Nothing.

I would hope that just about anybody who cares learned a thing or two about the Toyota “unintended acceleration” debacle. If your throttle ever sticks or your car starts moving without you commanding it to do so, put the transmission in neutral and turn the damned thing off! Although this was many years before the widespread Toyota issue, I was always prepared to execute this maneuver. I was tempted to now put my mental training into practice, but the only thing harnessing the immense power of that engine was its connection to the rear wheels. Removing that connection, by hitting neutral, would have most certainly allowed my engine to rev into the stratosphere followed by violent detonation (there weren’t rev limiters back in those days). So I decided to turn the ignition off first before doing anything else. I made this decision in the very few seconds between realizing my predicament and the moment just after the transmission shifted into 3rd.

The key clicked off and the engine began dieseling. With both throttle butterflies pinned wide open and the engine sucking roughly 12 cubic feet of air per second, mixing what can be equated with a shower head on full blast of fuel, I continued to accelerate. OH FUCK ME! I passed the 115mph mark. With the car still accelerating, I knew that shifting into neutral now would result with the engine over-revving and blowing up anyway. The sharp, and very appropriately signed, 25mph S-curves just ahead came into view. I had approximately ½ mile to get this car slowed down. If I kept this speed, I would be experiencing my own fiery death in just over 15 seconds.

The 1969 300 was equipped from the factory with four-wheel drum brakes. If you’ve never driven a vehicle will drum brakes before, you wouldn’t know that they are highly prone to brake fade. That is what happens when the friction lining of the brakes gets so hot that it no longer has any effect. My next actions had to be timed perfectly to get this car slowed down in time, much like precise sequence of emergency actions that must be taken at a nuclear reactor to prevent a catastrophic meltdown. I mashed the brakes as hard as I could and the speedometer had only dipped to 80mph when they overheated. I slapped the shifter into neutral. With the engine speed reduced by my drop in speed, it thankfully was no longer trying to accelerate, but it was still dieseling HARD. I was still going way too fast to make it through the curves and basically had no brakes. 12 seconds to fiery death…

I waited a very tense 6 seconds or so to let the brakes cool as much as possible. I now had about 100 yards to the first curve. I mashed the brakes as hard as I could again and entered the first curve at 50mph. The tires howled and the huge old car listed hard to the right like a sailboat on a port tack. The first curve sapped some speed which was aided by the fact that the curves had a slight uphill grade. I coasted through the remaining two curves at a much more appropriate speed. The engine continued to diesel, but had come down to about 1000rpm. As I coasted into South Range, I headed for the gravel shoulder and brought the car to a stop. I popped the transmission back into drive and the car lurched ahead a few feet with the engine coughing a few times. Then it was over. Silence.

I paused for a few minutes to catch my breath. My fingers were bright white, still gripping the steering wheel in sheer terror. There was smoke rolling out from all four tires and brakes as well as from the engine compartment. I pried my hands from the wheel and jumped out to pop the hood. Fortunately, nothing was on fire. The exhaust manifolds were glowing cherry red. The rest of the exhaust components ticked and pinged as they retreated from being on the verge of melting.

I removed the air cleaner to get a better view of the carburetor. The problem was immediately apparent. On old carbureted cars there is a nylon cam attached to a heat-operated linkage. It is called the fast-idle cam. The first time you step on the gas pedal when the engine is cold, this little cam rotates and holds the throttle at a barely open position. This was done to help these old cars warm up faster in the winter. As the engine warms up, the cam slowly rotates out of the way eventually allowing the idle to return to normal. Apparently if while rebuilding the carburetor, you forget to reinstall the tiny $0.15 steel e-clip that holds the fast-idle cam on its shaft, it allows the cam to rotate to an unnatural position. If this happens while the throttle is wide-open, it will pin the throttle in that position. If this happens on a 350 horsepower car with 480 lb-ft of torque, bad things happen.

I looked around under the hood and amazingly, there was the clip still sitting in a small depression in the top of the radiator, right where I left it. Little bastard! I absent-mindedly grabbed the clip and burned the hell out of my fingers, not thinking of how hot the radiator would be. The fast-idle cam was rotated back to where it needed to be and the clip was easily installed by hand.

I had that car for another 4 ½ years, although it did suffer a minor engine knock shortly after my episode. I learned a powerful lesson that day. When working on cars, no matter how small or insignificant the component may seem, every part is vitally important. Always double-check your work!