Fuel and (Compression) Ignition

Fun fact: The time it takes to prime a fuel system is equal to the time you crank the engine over with cracked injector lines in to get fuel to the pump, plus the 2 seconds you spend sucking on the fuel line because you gave up and decided you needed a quick test to verify a plugged line. After these 2 seconds, you’ll conclude via a mouthful of fuel that you really only needed 2 more seconds of cranking the engine over to prime the system. This is wrong: no matter how much longer you cranked, you still would have needed that additional 2 seconds to poison yourself. And no matter where you open the line to check whether it’s plugged, the fuel will be lurking 2 centimeters from the point at which it would start dripping out before you check it.

Nonetheless, after the considerable exercise of bleeding all the air pockets out of the fuel system, the 4BT cackled to life once and for all, emitting no more than a faint wisp of smoke to signal its long dormancy. To get it moving required bleeding the newly installed (albeit highly used) clutch hydraulic system. After tiring of trying to do it properly using a 2×4 to wedge the pedal down while I crawled underneath and cracked the bleeder screw on the slave cylinder, I followed the recommendation of a poster on ford-trucks.com, who ventured to a chorus of catcalls that when stuck doing this alone, putting your foot on the pedal and shoving it at the firewall 150 or so times will produce the same result. The Dodge power steering pump, while leaky, eventually worked it’s own air problem out and the steering effort ceased to exist. Before I knew it, I was doing passes by the shop, giddy at the sudden clearing of problems and how well the drivetrain worked all of a sudden. The gearing seemed reasonable even without the overdrive hooked up, and the turbocharger, purchased after a less than diligent amount of research based on a sticky thread on 4btswaps.com, howled like a Pratt & Whitney with nowhere near the predicted lag.

To produce this scene, buy a brand new drum from Napa. Clean with brake cleaner, then coat it with some caliper paint and lovingly place it on your rebuilt rear brake assembly. Then let it languish in the driveway for 3 years.

Not a moment too soon, this turn of events produced a charge of energy. Gone was the chore of it all, and with a few more adjustments, I decided to limp the truck home so I could swap out the parking spot. It was then that that I was reminded of the one knock on these swaps, which is that it is a big, combustion ignition 4 cylinder, and anything that is not secure will fall off the truck from the rattling. About 5 miles in, the comfortably uneventful ride because an unnerving series of pings and pops of things falling out of the engine compartment. After so long, there were bound to be a few bolts left around, I thought. But the fallacy of this revealed itself with a quick check under the hood. Injector line hold down bolts were missing, and the pyrometer probe had worked its way out of the exhaust manifold. The following day I took note of the increasingly terrible body fitment, notably the huge gap between the cowl and the hood. After a smack of the forehead upon realizing just what this was, I opened the hood to inspect the bolts that held the front clip to the firewall.

Loctite it or lose it! Fortunately, these have held tight after retightening with Loctite on the threads.

Fortunately, as these things are addressed, they seem to remain resolved rather than keep popping up. But I began to wonder if that vast chasm between the time when the truck is torn apart and the drivetrain is on the floor in the corner, and the moment it runs, is not as large as the one that lies before me now, between a running and driving truck and a good one.

What stands between a runner and a good truck.

Next up, the last thing before The Avocado is a true driver: getting the front brakes to work properly.


Reviewing the last entry, it seems we left off back in some dark days of troubleshooting a discouraging reading of “0” on the oil pressure gauge every time we spun the engine over. There was no firm answer, even from my long trusted repair shop, as to why the oil pump wouldn’t prime. The only reasonable thing to do was to retrace what little work on the engine I did before installing it, which was pull the pan and pickup to have them modified to fit the infamous 2wd Ford rear steering mechanism. I had purposely avoided messing with the engine internals to avoid precisely this. There was no doubt the fabrication work to notch the pan and elongate the pickup tube was flawless, but there was no better place to start.

Surely my luck had to turn for the better, and it was with that in mind that I left the engine hoist in the corner and dove underneath to see if the pan would come off with the engine in place. Sure enough, dropping the pan allowed just enough room to disconnect the oil pickup tube and let it fall out of the way and into the pan, which in turn allowed me to move the pan rearward just enough to turn it sideways, where things paused just long enough to remove the front sway bar. Then the pan came out, and distant memories came flooding back as I inspected the pickup tube and the shoddy work I had done on the bracket which secured it to the block.

While the fabricator inserted the specified amount of tubing into the middle, it was up to me to realign the bracket that mounted the tube to the bottom of the block, and it was clear I needed to humble myself and start there. Brow furrowed in suspicion, I then recalled our kitchen countertop and it’s machined granite surface, which had previously saved the day as a surface on which to sand a warped Volvo B21 cylinder flat enough to keep its new head gasket from leaking. I went inside and held the pickup tube to it to see if I could detect any telltale wobbliness and thus explain the oil suction problem. But it was solid and felt flat. I then tried one more thing: holding the flange of the suction tube flat against the countertop with the mounting bracket over the edge of the table, where it would be hanging in midair rather than pressing against any surface. Then, having established that the tube was firm and flat against the countertop, I swung the opposite end where the mounting bracket was to the edge of the counter to see if it slid on as true and flush as it seemed to be. It was at that point that the problem with the whole setup became glaringly apparent. The end of the mounting bracket was about a half-inch below the top of the counter. Putting the whole assembly back on the counter, I then lowered an eye to see if I could see any light shining under any portion of the pickup flange that mounts to the bottom of the oil pump. I could. Despite the fact that the tube felt flat and true, it was not.

What the ???? Apparently, this mangled mess was deemed acceptable late one night. Cutting the bracket illustrates via the overlap when laid on a flat surface just how incorrectly things were done, and the length caused the oil feed tube to remain unsealed on the other end.

With that load lifted, I gleefully reworked the bracket, bounded back to the shop and, with new gaskets and renewed enthusiasm, reinstalled the pickup tube, and buttoned up the oil pan. I lowered the truck back down, put the oil back in, and spun the starter over, half wondering if I even needed this tedious verification of such a slam dunk fix before attempting to start the truck for real.

Using steel rod and a jig to weld up an accurate if homely fit.

0 psi.

It didn’t take many goddammitfuckshits to realize how little there was to lose at this point. One piece of advice I had gotten from my favorite shop – though they had never had to do it on a Cummins – was to pull the pump and pack it full of grease so that any opportunity for the passage of air could be removed until the pump has primed. This was also a rare point of consensus on the forums. Thankfully, the oil pump on a Cummins B engine is amazingly accessible, held by 4 bolts right behind the timing cover.

In a just world, such agony should be rewarded. I rewarded mine with a Milwaukee 12V variable speed trigger ratchet. The amount of time saved with one of these is incredible. I was staring at my oil pump within fifteen minutes of deciding to open it up, courtesy of sicking this little beast on the 20 or so bolts that hold the timing cover in place. And, just as quickly, the trying uncertainty was once again replaced with the lightness of certitude, as I discovered that of the four bolts that held the pump in place, 3 were barely tight and nowhere near the torque spec for those bolts, and the fourth was falling out. It seems that whoever installed this pump did so a) recently, as the inside of this assembly was unbelievably clean; and b) with little care. I was ecstatic that the pump didn’t seal, affording me the opportunity to address it.

After packing the crevasses with grease and filling the remaining empty space with 50 weight oil, I put the pump back in the motor and buttoned things up. Shortly thereafter, I jumped the starter solenoid and watched a geyser of oil flow out of the disconnected turbo feed line.

Disconnect the turbo feed line and plop it into a cup to check oil flow prior to startup.