Fuel Injection

EFI Progress

Saturday afternoon was free of commitment, so I made a plan Friday night. I’m still working backwards with the EFI to try and diagnose the fuel/air mixture issues, so I thought I’d try to replicate the success I had two weekends ago by swapping the old carb back on, run the engine up to temperature, and then slap the Sniper back on to see if it would begin learning.

The first thing I did was download updated firmware to the SD card and updated the handheld and computer in the carb. The original file was six years old, so I figure they’d made a lot of updates since then.

I set the worktable up in the driveway, hauled all of the tools and hardware back out, and set up a camera. Pulling the Sniper off and putting the old carb on is easy at this point, and while I was there I removed the clear fuel filter I’d installed after the first two on the EFI fuel line. I strapped the boat tank to the bumper, connected the battery leads to the electric pump, and filled the float bowl. It only took two turns of the key to get it to light off, and with one adjustment I had it idling happily. I let it run for about ten minutes with the cap off the radiator, and then noticed it began bubbling, so I put the cap back on. I’d topped the cooling system off with about 3/4 of a gallon last week so I wasn’t afraid to run it this time.

When it was good and hot I shut it down, capped off the fuel, and pulled the 2300 off the engine. The Sniper went back on easily (I hadn’t disconnected anything) and I connected the electrical leads back up to the battery. Crossing my fingers, I fired up the engine and smiled as it started idling smoothly—faster than I wanted, but smoothly. I let it idle for a while and recorded a couple of log files for diagnosis, then shut it down to see if it would start and run consistently, which it did.

Then I tried to use it to bump the clutch, where you basically put it in middle gear, stomp the brakes, and start the engine. The force of the starter is supposed to break the clutch away from the flywheel. But my starter is very sick, so I couldn’t get it to budge. I shut the engine down and let it cool off for the evening.

Sunday morning between showers I walked back out and tried a cold start. This was the real test: to see if the Sniper unit had learned anything. I said a prayer, turned the key, and it fired right up—but more importantly, it idled smoothly and a lot slower than it had when it was warm. I did hear the fuel pump whining on the rail when I gave it gas, so I have to ask the pros whether or not that’s normal. I took another data log and saved it to my computer, and buttoned the truck up as it began raining.

The other thing I noticed was that the engine is leaking at the mechanical fuel pump location, so I fabbed up a flat steel block off plate out of 16 ga. steel for when I get under there and pull the pump off.

That’s about all I can do this week with our trip to Nats coming up; I haven’t heard back from the transmission shop yet, but I’m going to call on Monday to see if they can give me a time estimate, and that will dictate my travel plans.

Posted on June 8, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall, Video

Musical Carbs

I had a plan going in to Sunday morning, after sitting back and thinking about all of the symptoms I’ve been facing with the carburetor. Typically when i’m working on mechanical or computer problems I’ll diagnose things backwards until I get to something I know is working. Then I move forward until I’ve identified the fault. On the carburetor, I knew that the engine spark timing was off, and the only good way I know to adjust that is to loosen the distributor while the engine is running and spin it slowly until the idle smooths out.

I figured the best way to do this was to put the old Holley 2300 back on the engine and work through the problem mechanically. Unbolting the Sniper from the engine, I put it aside, resting on some cardboard, and disconnected all of the wiring. I pulled the old carb from one of my spares bins and swapped it onto the engine, plumbing it to the boat tank through an electric fuel pump. With a couple squirts of 50-1 gas in the throat, the engine fired right up but sounded very choppy and died off after about 10 seconds. I got a couple of backfires out the throat of the carb—a sure sign of bad timing.

After verifying this was consistent behavior, I got it running long enough to get out to the distributor and slowly twist until the idle smoothed out and the throttle picked up. Then I tightened the mixture screws (they were wide open from last fall, when I was battling the dead condenser thinking it was a fuel issue) and adjusted the throttle until it was idling happily by itself.

Relieved, I let it run for about 10 minutes and shut it down, figuring it was warmed up enough to give the Sniper a hand. The learning feature in the Sniper control unit kicks in after the engine is warmed up past 160˚, and that was what I was shooting for: I wanted it to learn how to adjust the fuel/air mixture and self-meter. Friday evening I’d pulled the water neck open and examined the thermostat that was in the engine. I figured I’d find something crustier than a wino’s beard but the passages and thermostat looked almost brand-new, which was a pleasant surprise. I put a new 180˚ unit in and closed it back up.

I hustled around the engine and got the Sniper back in place in about 10 minutes, verifying I had reconnected the electric leads to everything, said a Hail Mary, and fired it off. It started immediately, and ran a lot smoother than it originally did—but was still hunting for the right fuel/air ratio, surging and fading. I let it run for a couple of minutes, noting that the temperature was reading 178˚ but knowing that the radiator wasn’t full, and shut it down after watching the Learn setting on the control unit struggle to balance things out.

I tried to restart after a couple of minutes but the battery sounded tired, so I hooked the tender back up and let it cool down. The Sniper says it’s reading 14 volts when the engine surges, but I’d bet the alternator is dead so I’ll source a new one after I verify its condition.

So: I know that the timing on the engine is set more correctly than it had been. I know that the Sniper will start the engine and run more consistently than it had been. I know I probably need to adjust the timing settings in the control unit again to better match the engine, and I know that the water passages are clean—but need more coolant.

With a little more time to kill, I got my 3M automotive tape out and finally put the International badge on the rear door. Looking at the rear quarter, I decided I wanted to add the Travelall badge that belonged there too. With the taillight removed I was able to see where the bondo had filled up the original mounting holes and used a chisel to carefully scrape it away to where I could see them. Then I drilled them out and widened them until the posts on the badge fit the holes perfectly. With some more tape the badge went on easily, and now the truck looks even more legit than before.

Posted on May 27, 2025 | by bill | Leave a Comment | Posted in Carburetor, Fuel Injection, Travelall

Spark Testing

My plug wires showed up yesterday, which was a surprise. After using the Scout to jump the OG-V (the dome light stayed on for some reason and drained the battery) and charging that up, I put the spark tester on cylinder 3 and turned it over: there was no spark. Then I put the tester on the coil and cranked it again: there was one initial spark and then nothing after that. This is puzzling, and clearly something isn’t configured correctly. But it checks out with what the engine was doing earlier—in previous attempts it would almost catch and then just crank.

Posted on May 8, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall

Sparky

Update 5.24: I’m trying to come up with a plan for the Sniper kit to work out the bugs. From a lot of the other posts and videos I’ve seen, guys with International engines have been able to hook everything up and just go, but as I recall there was something off with the timing on my truck before I installed it. Fixing it is going to require some more experienced help, so I’m going to call upon Bennett to give me a hand. I’m also looking at being able to view the data logs from the Sniper, which is only available through software that runs on a PC. Refurbished PCs are pretty cheap these days, so I could probably find something for 100 bucks—but I’d like to avoid that if possible. I want to talk to Holley support and send them the datalogs, but I have a sneaking suspicion their first question for me is going to be whether or not I verified the distributor is in the right position. So I’m in a bit of a holding pattern here.

The other thing I’m aware of is that in order for the system to use the self learning feature, the engine needs to be warmed up to 160° or higher. I have never looked at the thermostat in this truck, and I’d like to swap in a known good one just to be safe. That should be a relatively easy thing to do this weekend.

Update 5.16: With a new condenser/points unit installed, IT RUNS. The idle is super choppy and it dies after about 10 seconds, which means the timing is completely off, but it starts right up as advertised. Now I have to sort out the timing issues and figure out where it’s happy. I had the timing dialed in pretty well with the carburetor last fall before I started welding on the truck and burned the condenser out, so I think it’s a matter of finding where the sweet spot is in the sniper settings to make the engine happy. I’ve got a bunch of reading to do today, and I’m going to spend tomorrow (Saturday) working to get it smoothed out.

Update 5.14: I have a new points/condenser unit on order, and I’ll swap that in tomorrow. The thinking here is that the condenser (essentially a capacitor) isn’t storing a charge in between the points opening and closing, which means there’s no spark making its way to the plugs. In the Delco distributor I have the points/condenser are an integrated unit so it’s not a simple matter of unscrewing just the condenser and swapping in a new one.

Update 5.11: I bought a new spark tester from H-F and verified it was working on the Scout. There’s no spark at the coil when I put it there; this verifies what I suspected. Next I’ve got to use a test light to see if I’ve got power going to the coil with the key on at both sides of the poles, then see if there’s power in the distributor.

I got really discouraged yesterday and let my anger get the better of me; instead of taking a step back and researching next steps, I let my ADHD run wild and dicked around in the garage for the rest of the day.

***

I’m in a holding pattern on the fuel injection project until some parts come in. The big holdup is getting a new set of spark plug wires after the number four wire snapped off in my hand. I thought I had kept my old set from the Scout in the spares bin, but apparently I tossed them—all I have is a coil wire in the parts bag. As I write this, it occurs to me that I can pull one of the wires off the Scout and use that to test the ignition system (duh). Basically, the plan looks like this:

Pull the #8 plug (International SV-series engines time off of the number eight cylinder)
Spin the engine until # is at TDC, replace the plug
Make sure the rotor is aligned correctly, pointing at the #8 wire
Make sure the spark plug wires are routed in the correct order – CHECK
Check for spark at the coil – NONE
Check for spark at the plugs – NONE

If all of those things check out, and the engine still won’t start, then I’m at a complete loss. I know I’m getting fuel, and the EFI system should be metering air, so the only thing remaining would be spark. I did fool around a little bit with timing last fall, but the truck ran after I adjusted that. So I’m thinking it’s got to be an issue with the ignition system. I do still think the starter needs to be replaced, but I want to sort out all of this other stuff before I start throwing more money at parts.

Posted on May 7, 2025 | by bill | Leave a Comment | Posted in Electrical, Fuel Injection

Wiring Up, Wiring Down

Last night I took advantage of some warm weather to finish installing the second relay in Darth for the Sniper control unit. This mainly involved a screwdriver and a lot of small zip ties to clean up the wire runs and get everything out of the way. I’d already built all the wires and heat shrunk the connections, so all I had to do was screw the relay into the metal panel and then screw that back into the firewall. Then the wires got cleaned up and routed along with the existing wiring.

When that was done, I wanted to see if I was getting spark at the plugs, so I pulled the boot off the #3 plug, and… the connector snapped off the wire. These wires are brand-new, so this is really frustrating. I don’t have a spare set in my stores, so I ordered a new one which should be here this evening. The next steps are going to be:

Checking spark at the plugs
Verifying I’ve got the wires connected in the right order from the distributor to the plugs.
Putting a third, transparent fuel filter in between the stock Holley unit and the carburetor to verify we’re getting gas (I can smell it, but need to verify).

Posted on May 2, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall

Halfway There

Super-sketchy temporary wiring proof of concept

A new 30amp relay came via Amazon this afternoon, and I did a quick and dirty wiring job to get it connected to constant power, a ground, the ignition circuit, and the carburetor. It wasn’t pretty but the truck turned over, and more importantly, the Sniper unit stayed on. The engine didn’t catch, however, which is getting really fucking frustrating.

So next up, I’m going to pull the mounting plate I used to organize the auxiliary fuse panel, add the second relay alongside the first, and use that as my mounting point. Then I can run clean wiring from there.

Posted on April 23, 2025 | by bill | Leave a Comment | Posted in Electrical, Fuel Injection

Relay

One of the proposed solutions to my EFI cranking problem is to wire a relay into the ignition system which will provide constant power to the Sniper head unit. Apparently it’s pretty common for old vehicles to have a voltage drop between the Run and Start positions in the switch, which the Sniper unit isn’t designed for. My first course of action will be to swap out the ignition switch with one of the spares and see if that makes any difference. It could be something as simple as a poorly made modern switch, which wouldn’t surprise me.

If I can get one of the two to work reliably, then problem solved. If not, the next step will be to wire in a simple relay to the ignition circuit which will provide constant power to the head unit and keep it live. There are two types I can use: a simple 30 amp on/off type like I’m using for the auxiliary fuse panel. The other is an adjustable design with a potentiometer which allows for the amount of time the circuit holds a charge. I don’t need it to stay on for 30 seconds after the switch is turned off, just enough to keep the head unit working.

Posted on April 18, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall

Fuel Injection Update, 4.14

A proper inlet fitting arrived in the mail on Friday and I had to wait until Sunday morning after the rain had passed to do a test fitting on the carburetor. I could only get one in blue, but you’ll never see it under the air cleaner. Thankfully, it cleared the water neck with about a half an inch to spare, so I tightened it down and made a list of preflight checks that had to be done before fired off the engine. First, I replaced the existing positive battery cable with a bigger fatter one. I’ve always wondered if I’m not getting enough cranking amps from the existing cable and decided to improve that situation. This took a little more time than I thought because the starter is in a really lousy position on C series trucks. It’s in between the engine and the frame rail and directly over the front axle so it’s going to be very difficult to swap out if that has to happen.

Then I pulled the plugs and put a borescope down into the cylinders one by one to check for any water in the cylinders. I did this because I drained a bunch of water out of the gas tank and I was afraid I’d pulled a bunch into the engine and possibly done some damage. I found no evidence of water or rust, just dirty piston heads that need to be cleaned up with a long idle and some time on the road.

Next, I had to get a bunch of new gas and get it into the tank, which is harder than it looks because I don’t have an angled funnel. After visits the three different stores I found something that mostly worked and put about 4 gallons of gas in the tank. Interestingly, the first time I turned the key to the accessory position, the fuel gauge worked, but it worked intermittently since then, so I’ll have to figure that out. With that done and the wiring to the Sniper connected, I cleaned out a jug and set it up in the engine bay to catch fuel.

The first test of the system is to boot it up and program it for the type of engine, cam, idle speed, and a couple of other settings. Then you program it, and do a couple of fuel system flushes to run clean gas to the system. After I did this, I connected the fuel lead up to the carburetor, said a prayer, and cranked it over for the first time.

It didn’t immediately catch, and I noticed that the Sniper control unit had rebooted itself; this should remain on constantly. Doing a little Internet digging I learned that other people have had this problem and it’s got to do with a gap in continuity when turning the key. Walking back through the main points of failure, I tested the jumper to switched power on the fuse panel and verified that was OK. The power leads to the harness were connected correctly. That left the ignition barrel.

This ignition barrel is brand new. I bought it the first year I had the truck, and I believe it’s been wired correctly, but clearly I’m going to have to pull it out of the dash and check it over again. I’ve got two spares I can swap in for testing—the original and the one out of the ’67. I’m going to go out and take some detailed pictures of the ’67 barrel and the one in the truck and compare them, along with the diagram I have from the service manual. I’ve been thinking about pulling that one apart and swapping in one of the new ignition cylinders (I don’t have a key for either one) so that could be a cheap way to test the system, with the added benefit of getting the entire truck to work on one key.

Finally, I checked for spark while I was turning the engine over on the #5 cylinder and didn’t see anything on the indicator, so that’s another thing to check.

Posted on April 14, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall

Fuel Injection Video Update

Here’s the wrap-up video from the past two weeks, which includes all of the work I did installing fuel injection and the eventual solution to fixing the barn door lock mechanism, which involved a Dremel and some very careful surgery on a lock cylinder. This one took some time to produce because I was working with ~90 gigs of video footage which brought my computer to a crawl.

Posted on April 10, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall, Video

Fuel Injection Update

With the exception of one stupid fitting, the Sniper is installed on the truck, the fuel tank is back in place with a new sending unit and return line, and the hoses are (hopefully) routed in a way that will feed fuel to the engine reliably. This was not without struggle, and required a lot of problem-solving.

First, I was having issues with electrical continuity in the original fuel sender. I could measure resistance at certain points in the swing of the arm but it wasn’t consistent and no amount of adjustment was working reliably. I was afraid the issue might be my $9 Harbor Freight multimeter so I splurged on a fancier $25 model and got the same result. Doing some research, I learned that there are new senders available, but only for the 15 gallon tanks installed on pickups, which are a different size than the 19 gallon tank I have. I did track down a forum post from 2007 which claimed that a sender from a 1957 Thunderbird would fit with minor modifications, and the pictures seemed to show something very similar to what I already had. So I took advantage of a solid return policy and ordered one from AutoZone with free one-day shipping.

On the bench, when I compared it to the original sender, it looked a little different, but putting both of the units on the bench base and comparing the arc of the center arm, and their length showed that they were roughly the same. The new unit has a brass float and tested flawlessly with the multimeter, so I went ahead and put that in the tank. After cleaning the inlets on the tank out, I sealed everything up and got it ready to put back in the truck. This took a bit of maneuvering, but once I had the hoses in place, I jacked it up and got it into position.

At this point, it was clear I would have to modify the tank straps to allow for the extra inch and a half I had to add between the tank and the body of the truck to clear the return inlet. I cut the brackets off with the cut off wheel, and fabricated some new straps out of 16 gauge steel. After welding the brackets onto the strap extensions, I brought them out to the truck and welded the two sections of strap together. When they were cold, I cleaned them up, painted them, and then got them ready to hang the tank.

This had taken a lot more time that I thought it would. I fed the sender wire over the frame rail, hooked it back up to the wiring harness and fed the return line up through the body mount to the engine bay. Working methodically, I reattached all of the hoses to the fill tube, the vent tube and the fuel line itself. I was very careful measuring and cutting the hose that had come with the Sniper kit and it looks like I’ve got just enough to finish the job. The only thing left to solve is finding a 90° fitting for the fuel inlet on the carburetor, which butts up right next to the water neck on the engine. I’d ordered two 90° fittings and had them sent overnight via the jungle site, but the second fitting is just too long to fit in the space available. So I’ve got a call Holley’s tech support line to see if they can suggest a solution.

At this point, everything is complete, minus that fitting. When I’ve got that solved, I can put gas back in the tank, run a bunch of it through the system to flush it, and do all of the preflight checks for the carburetor computer. The other check I wanna do before anything else happens is to pull a couple of the spark plugs and eyeball the cylinders for any sign of water or rust. After draining a bunch of water out of the fuel tank, I’m concerned about it being in the cylinders, and I want to look for any signs of hydrolocking. If there is any water in there, I’ll bump the engine over a bunch of times to clear it out.

In non-engine related news, I did a bunch of work on the rear barn door handle on the bench to fit a door lock correctly in the barrel without having it fall out. What I had to do was take a Dremel and carefully carve a channel out of the back of the lock cylinder to accept a standard lockring. I used the pair of pliers to squeeze it down to be the same diameter as the cylinder, trimmed the outside edges, and then inserted it into the barrel. I was able to get a pair of lockring pliers inside and open it up so that it stayed inside the barrel. I installed it first thing Friday morning and just like that I had a locking rear door for the truck.

I’m sorry, I would have taken pictures but I was hustling pretty much all day Sunday from 10AM to about 7PM to get this done. I was able to get the truck down off the jack stands and under a tarp just as dusk was falling. Monday morning is rainy so I’ll see if I can get back out there on Tuesday to open things back up.

Posted on April 7, 2025 | by bill | Leave a Comment | Posted in Fuel Injection, Travelall, Welding