Tuesday, April 13, 2021

Injector-Go-Round (Part 2)

Today, we continue and complete the efforts to get old used stock injectors from Hapy to work in Flash, and then brand new higher-performance injectors installed into Hapy. Fun with injectors starts.... now.

Now comes the fun part. With the wedged-nut extractor tool I mentioned in part 1 (See Injector-Go-Round Part 1), I pulled the injectors out of Hapy, Then, I pulled the old injectors out of Flash and installed Hapy's old injectors into Flash. That sentence took less than 10 seconds to type, and I feared it would take all weekend to do. It was actually fairly uneventful and quick. On Friday night, I set myself up by putting Hapy and Flash near one another, and then shooting the injectors where they enter the head with the trusty old Kroil penetrating oil. The next morning, I cleaned around the injector-to-head points, took my slap-together injector puller / slide hammer and all 8 injectors popped out with little effort. Seriously, each injector took fewer than 5 pops with the slide-hammer, and none of the "pops" had much force at all behind them. Honestly, I was being gentle because I didn't want the wedged nut to fall off the hammer. So, I held the slide between my index finger and my thumb and gently pop-pop-popped, moving the slide less than 4 inches each time with a flick of my wrist. I think the Kroil really helped, though I expect there will be some who bristle at the thought of letting some penetrating oil slip into the engine. 

I carefully arrayed the brackets, bolts and washers (excepting the one I lost) so I could re-install them in the same spots. In Hapy, I left the injectors loose, but still in their respective holes while I completed the extract on Flash, cleaned the holes and the head mating surface. Then, in one move, I pulled the injectors from Hapy, carried them across the driveway like a cat's cradle and set them into Flash's head. Ideally, I would have replaced the copper crush-washers on the injectors, but I didn't have replacements on hand, and this was the day I had to do this. *Dumb short-cut actually taking more time warning*

The install of the new-to-Flash injectors was fairly straightforward. Once the injectors were set in, I cleaned each bracket, rested it into place, and then lightly threaded the bolt through. Once I had all 4 in place, I threaded them down finger tight. I plugged in the 3rd-injector plug, set the glow-plug harness under the hard-lines and then re-connected the hard-lines to the tops of the injectors, but only barely threaded on. Once the lines are in the right spot, the compression fittings on the pump can be tightened down. Then, I wrenched down the brackets to around 10 foot-pounds (spec says ~15), snapped the glow-plug harness onto the glow-plugs and connected the return line to the injection pump.

Drift, Torque, Repeat
At this point, I test-cranked the engine to force air out of the hard-lines. There are a few ways to do this, of course, and the video I mentioned in part 1 is as good a way as any. He did the injectors in pairs while I did them one at a time, tightening the hardline at the injector end as each injector-to-hardline point spat out fuel. My one-at-a-time method moves from injector to injector based on the way they are connected to the injection pump: closest-to-the-ground one first, highest one last. My thinking is that any air in the pump will work its way up that way. By the time I was on the last injector, the engine was trying to fire.

I got that last line done, and Flash started right up. I could see some vapor puff-puff-puffing above the head, and could hear a "psst-psst-psst" noise, so I knew there was a leak. Boo helped me here, by jumping into the driver-seat and starting the engine while I looked and felt for the leak. It was around the #2 injector, but not at the hard-line mate point. It was around the injector near the head. Engine off, I grabbed a socket extension to use as a drift. I lightly smacked either side of the #2 injector bracket near the injector. Then, I re-torqued the bolt. I was surprised by how much more I could turn the bolt (like 3/4 a turn), so I repeated the process on the other 3, and continued to do this until the bolts torqued down at 15 ft-lbs and would not accept more after more drift-smacks.

This process worked very well. When we test fired it again, Flash started right up, made no funny noises (nor puffs of vaporized fuel) and ran strong during the test drive. The biggest indicator of our success was the near-immediate start the following morning and no cloud of smoke. He had been getting harder and harder to start in the morning. I now conclude that his old injectors were leaking (evidence of that was found upon their removal, as they leaked all over the paper shopping bag I set them on), and the fuel system needed to prime every morning, causing the long hard-start effort. I decided to change his oil immediately, while waiting for the delivery of the new injectors from KermaTDI.

Priming the Injection Pump
During the oil change, I discovered that the #2 injector had actually leaked at the head again during the test drive, and concluded that replacing the copper crush-washers (or injector seals) is not optional. I got a replacement set from the local parts store (not DIP, still bummed about that) and re-did the removal / install. This time, I did a pair of injectors at a time, starting with #1 and #2. Oddly enough, the injector pump lost it's prime in the few minutes the system was open this time. Half as many injectors, loosened the lines less and it still lost prime when it didn't the last time when I did all 4. Ah well; just shows that luck is a factor. With the MityVac, I applied vacuum on the low-pressure return side (no more than 7 pounds so the seals inside the pump were never in jeopardy, and more vacuum would not have tangibly sped the process) of the injection pump until fuel appeared in the MityVac collection cup. Then, I buttoned things up, cleared the hard-lines of air by cracking the connections one at a time (bottom to top, like above) until Flash started. Again, I see no puffs, but I did the #3 and #4 injector seals anyway. Fool me once. After letting Flash sit for a few days, he lost prime again.

So, I ran another round of MityVac priming and got him running. I let him sit an idle while I got a really close look at the injectors. I noticed that #1 had fuel appearing around the injector mount-point into the head. The #1 injector is unique in that it has a cap on one of the return bibs. That cap was leaking. I didn't have a real one, so I made one from low pressure hose and a bolt. This helped, so after letting Flash sit for a few days he would start, albeit roughly. Believing that the low-pressure return lines I moved from Hapy were no longer viable, I considered my options for replacement.

Hapy Injected
Once KermaTDI had the injectors set up, they FedEx'd them over with a new set of copper seals. They arrived mid-week, but with the dicey weather, I waited to until the weekend so I could have a nice big block of time. Hapy's head had been cleaned when the old ones were pulled and I had stuffed rags into the injector holes so it would stay clean. With the injectors in-hand, I could at least prepare them for install by removing the "T" fitting from Flash's old #3 injector, and moving the low-pressure return lines onto the replacement set. The kit from KermaTDI delivered with brand new low-pressure return lines so the set up of the injectors was that much easier. With the injectors set up, and a new weekend day, I followed the same process I did with Flash, except for skipping the test-start parts. I am having issues with Hapy's ECU, so this is as far as I could really get.

I'll describe the test-drive once I have Hapy buttoned back up. Between then and now, I need to get his ECU sorted but at least the exhaust is back on. There's never a shortage of things to do. Couldn't be Hapy-er.

Thanks, as always, for following along.

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