'91 K5 Four Wheel Camper

[Babaganoosh]

Ouch, that is bad but good news at the same time. At least you know why it did it and what you can do to prevent it.



I'm glad I have a fuel pressure gauge on my dash now.

 

[ZooMad75]

Ouch, that is bad but good news at the same time. At least you know why it did it and what you can do to prevent it.



I'm glad I have a fuel pressure gauge on my dash now.

Well we confirmed fuel killed it. Why it did is still a point to be proven. Based on Larry and me brainstorming yesterday it may have been the fuel pressure regulator. Only because he had fuel pouring out of the vacuum line when he pulled it. The working theory being the regulator stuck and allowed the system to deadhead and spiked the fuel pressure to who knows what level. That combined with a weak injector could be all it needed to push past the injector and flood a hole.

If the truck has set for any serious length of time my habit is to cycle the key 3-4 times to prime the fuel system prior to hitting the starter. I moved the truck three times after getting back from Moab. Once to get it off the trailer, then to move it in front of the garage and then again to put it next to the garage. There was days to weeks between those moves though. So if I did my normal cycle the key business the potential is there to dump a lot of fuel. Though the last time had the right amount to hydrolock the one hole.

I doubt it was pushing this much fuel while in Moab only because I checked the oil before taking off for steel bender and it was barely down anything one the stick. I’m pretty used to the 8.1 using oil on the trip which is why I checked it. Plus even if it didn’t hydrolock a cylinder the amount of fuel in the pan would have diluted the oil to the point of starving a bearing and causing a problem from lack of lube.

I do know this it’s getting injectors and a fuel pressure regulator with the fresh engine. We won’t have a repeat occurrence of this. Unless by some fluke of course.

I should have trusted my gut when I first found the fuel in the oil. That above all is what I’m more annoyed about over this mess. I should have never twisted the key without pulling plugs first with all that fuel I found in the pan. But I was under pressure to get the truck out of the way and just get it moved so I pushed without the right due diligence. Boy did that cost me.

Can’t really bitch about it anymore as it don’t change the problem. We know how it got hurt. We know what to replace to prevent it so that will be done. It should be fine once we get it back together.

 

[Fastereddie]

Well we confirmed fuel killed it. Why it did is still a point to be proven. Based on Larry and me brainstorming yesterday it may have been the fuel pressure regulator. Only because he had fuel pouring out of the vacuum line when he pulled it. The working theory being the regulator stuck and allowed the system to deadhead and spiked the fuel pressure to who knows what level. That combined with a weak injector could be all it needed to push past the injector and flood a hole.

If the truck has set for any serious length of time my habit is to cycle the key 3-4 times to prime the fuel system prior to hitting the starter. I moved the truck three times after getting back from Moab. Once to get it off the trailer, then to move it in front of the garage and then again to put it next to the garage. There was days to weeks between those moves though. So if I did my normal cycle the key business the potential is there to dump a lot of fuel. Though the last time had the right amount to hydrolock the one hole.

I doubt it was pushing this much fuel while in Moab only because I checked the oil before taking off for steel bender and it was barely down anything one the stick. I’m pretty used to the 8.1 using oil on the trip which is why I checked it. Plus even if it didn’t hydrolock a cylinder the amount of fuel in the pan would have diluted the oil to the point of starving a bearing and causing a problem from lack of lube.

I do know this it’s getting injectors and a fuel pressure regulator with the fresh engine. We won’t have a repeat occurrence of this. Unless by some fluke of course.

I should have trusted my gut when I first found the fuel in the oil. That above all is what I’m more annoyed about over this mess. I should have never twisted the key without pulling plugs first with all that fuel I found in the pan. But I was under pressure to get the truck out of the way and just get it moved so I pushed without the right due diligence. Boy did that cost me.

Can’t really bitch about it anymore as it don’t change the problem. We know how it got hurt. We know what to replace to prevent it so that will be done. It should be fine once we get it back together.

Good to see you making progress on it!

 

[Blue85]

(making mental note to check the oil carefully before next cranking the 8.1 over)

 

[ZooMad75]

(making mental note to check the oil carefully before next cranking the 8.1 over)

I would but man this is a fluke thing. I’ve been around 8.1 for a long time with my workhorse days and I can’t recall any 8.1 death that occurred this way. Two failures happen with 8.1’s. They get run out of oil and seize up or they get run out of coolant and get cooked. I’ve seen multiple both ways in RV’s. Never a flooded fuel deal.

If yours is a later version with the return less fuel system it won’t have a regulator on the rail anyway.

 

[Larry]

(making mental note to check the oil carefully before next cranking the 8.1 over)

Before we start getting the notion this could be an 8.1 specific thing to look out for, it isn’t. There is nothing unique with the fuel system on the 8.1 from a LS engines or any fuel injected engine for that matter…return type or returnless. A leaky injector is a leaky injector…even on a diesel. A leaky injector (for whatever reason) can kill any engine if not caught in time and depending how badly it is dripping, whizzing or flat out being a fire hose. Typically, you’d notice prolonged cranking at startup, poor drivability, smell fumes, etc. before it gets to the point of hydrolock. Rob got so accustomed to cycling the key a few times before start up due to a less than sterling fuel pump it probably happened pretty quick right before it locked up. My suspicion is the regulator was probably acting up for a while until the #3 injector decided it couldn’t take it anymore.

 

[Truckman4life]

Ford 5.4L engines had a tsb for injectors sticking. They would just pour fuel out the exhaust and the cat would make lots of white smoke.

 

[Chickntrk]

As a diesel tech I saw many engines destroyed because of one bad injector. The caveat here could be a TBI engine because fuel isn’t injected directly into one cylinder. Can still happen but the process will take longer and will usually wipe out bearings due to gas in the oil

 

[Blue85]

Two failures happen with 8.1’s. They get run out of oil and seize up or they get run out of coolant and get cooked. If yours is a later version with the return less fuel system it won’t have a regulator on the rail anyway.

Mine is 2003-ish so I have the regulator. Sometimes they run out of oil because the oil cooler lines start leaking. I think none of y'all have those, but I do.

There is nothing unique with the fuel system on the 8.1 from a LS engines or any fuel injected engine for that matter…

True. Many millions out there. I'm actually running exactly an LS fuel system on mine, up to the fuel rails.

 

[ZooMad75]

Mine is 2003-ish so I have the regulator. Sometimes they run out of oil because the oil cooler lines start leaking. I think none of y'all have those, but I do.

True. Many millions out there. I'm actually running exactly an LS fuel system on mine, up to the fuel rails.

Many a rv’er were surprised to find out about the oil consumption. Thankfully most were caught when the oil pressure dropped and they finally checked it. I had to presentations at rv rallies and it was a focal point to remind them to check it at each fuel fill up if not every other. Given gm’s rating of a quart of oil per 100 gallons of fuel used and we had 75 and 100 gallon tanks it was easy to gauge consumption.

Probably the more common failure to an 8.1 was due to severe overheating. We did three in one month at the dealership at close to $15k per job parts and labor. Each one run out of coolant. Unlike the trucks/vans that had 8.1’s with a pressurized overflow/reservoir with no cap on the radiator the workhorse setup was conventional with a cap on the radiator and old school puke tank.

The problem came in where folks never checked the coolant level in the radiator. If the overflow had juice in it that was good enough and they would never look in the radiator. They would go quite a while on low coolant and then eventually cook themselves.

But those examples just illustrate how odd my failure really is. If I had to pin anything down as a source the injectors and fuel rail were used and as such were really gooey. Larry had to soak and flush out the rail and soak the injectors. I was light on budget to get fresh injectors during the build. How it ran fine for so long is still a mystery.

 

[Chickntrk]

I’ve always gotten lucky, all my major failures were close to home. When I look back at all the stuff that’s happened to trucks I’ve owned and then looked at how and where it could have happened I’m amazed. Imagine driving cross country with the family and your RV needs an engine at $15k

 

[Babaganoosh]

I myself roll the key over to build fuel pressure to fire everyone. Mine sits for weeks at a time as well.

 

[Fastereddie]

I find myself doing the opposite. I like letting them crank for a few before they fire. Maybe get some oil moving first idk.

 

[Chickntrk]

I find myself doing the opposite. I like letting them crank for a few before they fire. Maybe get some oil moving first idk.

This has always been my theory, dunno if it’s right or wrong

 

[6872xtc]

I find myself doing the opposite. I like letting them crank for a few before they fire. Maybe get some oil moving first idk.

Yep. I saw equipment years ago that had a fuel solenoid kill to pre-lube the engine and turbo. Hold the switch, crank the engine until it had oil pressure for a bit, the release the fuel kill switch.
Even saw old engines that had a compression release to get the engine spinning, which guys would use to make oil pressure build before letting it fire.
I always crank my carburetor trucks over a bit before setting the choke and starting. I usually just hit start immediately with the EFI trucks and see if they spin a little before firing up.

 

[Larry]

I just jump in and crank mine and if it doesn't I started yelling WTF at the top of my lungs!!!

Luckily, that hasn't happened many times. Although, there was a few months a few summers ago I had to do the same as Rob where I had to cycle the key on the Suburban a few times before trying to start it due to a fuel pump with a drain back problem. It's funny, every fuel pump I've had to replace in my junk have all been due to pressure relief issues that cause prolonged cranking and not actually pumps that died and stopped pumping

 

[Wes Harden]

Mine will have a long crank or second crank if it sits for a week. Which happens frequently. If daily driven starts on first crank session

 

[dbcorvairracer]

Yep. I saw equipment years ago that had a fuel solenoid kill to pre-lube the engine and turbo. Hold the switch, crank the engine until it had oil pressure for a bit, the release the fuel kill switch.
Even saw old engines that had a compression release to get the engine spinning, which guys would use to make oil pressure build before letting it fire.
I always crank my carburetor trucks over a bit before setting the choke and starting. I usually just hit start immediately with the EFI trucks and see if they spin a little before firing up.

My dad has one of these on an FMC RV with a 1/2" stroked 440. That engine has never started without oil pressure already built up. You turn the switch on and you can listen and hear the pressure come up. There is also another port you can open up to pump the oil out of the system directly into jugs for disposal. I believe his was called "Turbo Life" The sales pitch he was given was that the guys driving garbage trucks and stuff like that would run them hard and do no cool down before shutting them down at the end of a shift or break time cooking oil in the hot turbo. The system would also be setup to keep pressure in the system while the turbo cooled down.

 

[ZooMad75]

New milestone reached. Thanks to @Capt Ron ’s used 8.1 emporium the Crawlabago has a new used fat block.

My plan was to get a reman but the cost was just too high for me to pull off right now and be able to actually drive it this year.

CaptRon has been sitting on this engine since he picked it up from Wade before he made the move out of Colorado. The history on the engine is a little fuzzy between Ron and I but the jist is it came from a Schwans medium duty truck and is pretty low mileage. Bonus is Schwans units run on natural gas so it’s should be very clean inside. The outside is spotless for sure. Still clean factory black gm paint.


It’s going to get all the seals replaced, top to bottom and front to back.


Proof of the medium duty origin. The oil pan is giant and has already been modified to remove the front section of the pan for clearance. I don’t think it will fit as the stock truck pan is really close to the ORD engine crossmember. A quick comparison measurement from a stock truck pan from the back of the pan to the front part of the sump was roughly 10 inches. In the modified medium duty pan it’s closer to 13 inches. Thats no bueno.

My buddy Bill made the trek up to Denver to fetch the engine and deliver it down to to Larry.




With the engine secured, motivation has jumped up some. I don’t have much I can do from up here with the truck at Larry’s. But I do have a little 8274 Warn winch I’ve been sitting on for well over a year and parts to upgrade it too.

I’ve picked up a control pack from the newest version of the 8274 that uses a allbright solid state relay over the original solenoids. I got a controller to match and 150 feet of synthetic rope from Warn too.

First up a quick cleanup of the dirty winch.

The winch wasn’t too bad actually. So it is going to get a a quick wheel job.
















I tried to push the control pack closer to the body of the winch but the slots for the hose clamps on the pack put it right on the inboard motor studs. So I had to put it where the outboard clamp went outside of the outer motor stud. This motor is still the original and not the newer unit. I imagine the new motor being longer would allow the pack to fit right. It will get the newer motor later but this will work fine for now. As it sits the winch itself is super smooth in all the functions I can do without powering it up. Free spool knob pulls in and out easy and free of any binding. With the free spool on the drum rotates super easy and smooth. Even with the free spool off the drum spins the gear train smoothly (opposite of the brake) and the brake holds like it should. It’s ready for install on the engineered vintage bumper that’s been stashed forever.

 

[ktmoutfront]

I am glad to see that engine go into use.