Wow such a shake down run.
Worst day of wheeling better than the best day at work??
Worst day of wheeling better than the best day at work??
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
for sure.
Yep low voltage and miss fire go hand in hand.
I unloaded the gear and hooked the battery to the trickle charger overnight so I could diagnose the issue in the morning.
In the morning I swapped the old 8.1L alternator in, no change so I knew it was a wiring issue likely.
I remember reading @ZooMad75 and @Larry talk about the CS144 alternator in the 8.1L resource thread so I went back and read through that information. Apparently the 8.1L "DS" style alternator relies on the ECU to send the signal to charge whereas the CS144 doesn't and the CS144 is readily available with better power options. It turns out I had a brand new CS144 AC Delco on the shelf from one of my L29 builds. I also had a L29 harness so I snagged the pigtail off that.
The CS144 is wired to the stock truck wiring (also 2 wire) and Larry made a comment about connecting the brown wire from the howell harness to the brown on the truck harness ("L" input on the CS144 plug).
10 minutes later I had 15.1V at the alternator and 14.5 at the battery.
In the morning I swapped the old 8.1L alternator in, no change so I knew it was a wiring issue likely.
I remember reading @ZooMad75 and @Larry talk about the CS144 alternator in the 8.1L resource thread so I went back and read through that information. Apparently the 8.1L "DS" style alternator relies on the ECU to send the signal to charge whereas the CS144 doesn't and the CS144 is readily available with better power options. It turns out I had a brand new CS144 AC Delco on the shelf from one of my L29 builds. I also had a L29 harness so I snagged the pigtail off that.
The CS144 is wired to the stock truck wiring (also 2 wire) and Larry made a comment about connecting the brown wire from the howell harness to the brown on the truck harness ("L" input on the CS144 plug).
10 minutes later I had 15.1V at the alternator and 14.5 at the battery.
I forgot to mention that during my bolt check Friday afternoon I found the leaf spring plate studs and u bolt (passenger front) kinda loose. These was the trail fix last year and the studs were used. Anyway, the nuts on the studs were starting to strip and the u-bolt was hammered. I had new studs from WFO however I had to run over to Ruffstuff to pickup a new u-bolt. Nice and tight now.
Damn that was quite the accomplishment! I'm impressed you knocked all that out and you were able to get some trail time.
What were your driving impressions of the new powerplant so far?
What were your driving impressions of the new powerplant so far?
It was a thrash last week, especially in the heat. I was feeling it Saturday night and Sunday for sure.
The engine runs smooth and quiet in comparison to the old 454 engine with peanut port heads and FiTech. The sucking noise of the throttle body injection 454 is probably the main difference. It’s still rowdy through the 3” magnaflow with increased rpm.
I’m having one minor issue with cold starts that I need to figure out. It runs for 1-2 seconds and dies unless I give it gas. It will do this 8-10 times before it runs on its own. I need to verify fuel pressure, I’ve read the 8.1’s like a little more fuel pressure. The regulator and injectors came with this engine.
Last edited:
The CS144 is the ticket. Mine just went a week keeping two batteries topped up even crawling around at 800-1200 rpm for hours. One of my batteries is a 1000cca deep cycle for the camper.I unloaded the gear and hooked the battery to the trickle charger overnight so I could diagnose the issue in the morning.
In the morning I swapped the old 8.1L alternator in, no change so I knew it was a wiring issue likely.
I remember reading @ZooMad75 and @Larry talk about the CS144 alternator in the 8.1L resource thread so I went back and read through that information. Apparently the 8.1L "DS" style alternator relies on the ECU to send the signal to charge whereas the CS144 doesn't and the CS144 is readily available with better power options. It turns out I had a brand new CS144 AC Delco on the shelf from one of my L29 builds. I also had a L29 harness so I snagged the pigtail off that.
The CS144 is wired to the stock truck wiring (also 2 wire) and Larry made a comment about connecting the brown wire from the howell harness to the brown on the truck harness ("L" input on the CS144 plug).
10 minutes later I had 15.1V at the alternator and 14.5 at the battery.
I’ve got mine set at 62psi at the regulator. I think Larry is a tick higher.
For the start/stall issue, you might need to bump up the mechanical idle speed a touch. Since it looks like you used the L29 throttle body, you’ll see a set screw next to the throttle arm on the housing. The iac should control the idle speed but sometimes it can’t quite handle it. It takes barely a 1/16 to 1/8 of a turn to allow the iac to do its job. The iac pintle could be sticky/carboned up but on a fresh build I’d doubt that.
The guy with the burb on our trip last week has a stock L29 swapped in and he was having an idle speed issue so I bumped his slightly. Didn’t take much at all.
Thanks for the insight and I see the set screw on the throttle body. I'll check that out.
What tool do you use to adjust that little throttle screw?
I gave the screw a slight turn, maybe 1/8 to 3/16 and it started on the first crank. Thank you!
It’s a little torx set screw.
Back on the trail, running awesome.
That’s awesome dude!
My envy knows no bounds!
I guess I shouldn't complain about mine taking exactly 5 Gallons, with the aftermarket aluminum radiator.
All in all, it was a successful trip however the engine started to run rough, slight stumble, smelt rich and smoked a little from the tailpipe. No CEL. At first I thought it was fuel related however driving out Sunday it felt like it might be running on 7 cylinders. At one point I killed the engine to see if a restart would fix it however it was a bitch to start and when it finally did it threw a fireball out the side exit exhaust. That to me sounds like an ignition issue. I need to pull the plugs to see if I can narrow it down to a specific cylinder. If not, I'll check fuel pressure and maybe consider yanking the injectors for a service. 7 of the 8 coils and the injectors came with the engine....
Last edited:
I forgot to mention that I upgraded the trailer with leveling jacks, added a spare tire mount and spare tire cover. I'll be adding a battery for the winch and possibly a solar panel to keep it charged.
Since you are going to go with a battery on trailer now you need to update to electric jacks 
I’ve been on the road for the last three weeks for work so I haven’t had a chance to work on the truck. After a long day of travel yesterday I woke up early to pull the plugs. Passenger bank of plugs are fouled.
During my disassembly of the engine I noticed the #2 injector wires were stripped back enough to expose the copper. I thought that was odd at the time however looking back I find that as a helpful clue that an issue likely existed before I had the engine. I’m wondering if it might be the injector harness for the passenger bank? @ZooMad75 @Larry @Wes Harden @Bent77
3 of the brand new AC Delco wires broke when I pulled them off so I’m going to upgrade those.
During my disassembly of the engine I noticed the #2 injector wires were stripped back enough to expose the copper. I thought that was odd at the time however looking back I find that as a helpful clue that an issue likely existed before I had the engine. I’m wondering if it might be the injector harness for the passenger bank? @ZooMad75 @Larry @Wes Harden @Bent77
3 of the brand new AC Delco wires broke when I pulled them off so I’m going to upgrade those.
That’s weird to my brain. I would think if the harness was bad the injectors wouldn’t be firing correctly. (Lean)
Also weird that all four on that side would be dirty(sticking open?)
Also weird that all four on that side would be dirty(sticking open?)
