moderate high temps, complete loss of power/missing (1 Viewer)

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Joined
Jul 4, 2011
Threads
22
Messages
273
Location
Texas
Background:

1997 LX450
triple locked
SC'd
35" tires 4:88 gearing
hood vents
disabled aux fan
factory sub tank
91 octane
3/4? full main tank, full sub

SO I went wheeling last weekend, Texas desert, ambient temps were in the mid 90's F. out for about 30 min on some ranch roads 5-10 mph max, running 4 low unlocked, A/C on medium. 1-2 small ledges to overcome, stopped to wait on some jeeps to get up a ledge and left the rig sitting for 10? maybe 15 min? running and A/C on (heat soak?)

Started running real bad, like i had a plug wire shorting or something. about 50% reduced power trying to limp up a few rocks getting to the ledge to get out of the dry creek.

locked up the diffs and tried to get up and had zero power from the motor. Just sputtered and tried to stall. On one of the sputters i got a surge and shock loaded drive train and blew the passenger birf? Granted I did have the front locked and wheels turned, so axle breakage was kinda to be expected, shame on me.
I shut it down and opened the gas cap to vent and popped the hood on recommendation of one of the jeep guys.
Started back up and same situation sputtering ect.

Winched up the ledge and started fuel transfer from the subtank, and unplugged the hose to the charcoal can to the tank. engine got better and I was able to drive back to camp and bummed a trailer ride home.
While at camp I noticed fuel burping out of the Charcoal canister hose to tank that I had unplugged.

Some of the jeep guys were saying that the sputtering problem was vapor lock? Caused by running premuim (possibly winter formula) fuel that was boiling?

Does this sound right or do I have a problem somewhere else? (I have used search)
If this is the issue, would putting a inline fuel cooler help anything?

ON the broken axle/ birf. I haven't had time to tear it down to see exactly what is damaged, but have a pretty good idea. Been looking at replacement options, and have all but settled on RCV 30/30/30 with the RCV drive flange and ARP hub studs. Idea being to over build the weak link to possibly avoid future breaking, and have a lifetime warranty on the major parts if they do break. Searched reviews here look to have good reviews of RCV.
Is the 30/30/30 overbuilt excessively? I am not planning on hardcore crawling, but want some durability for mild>moderate occasional wheeling.

If this is not a good direction, I'm open to suggestions. Stock seems too expensive.

Thanks!
 
Can't help much with the running problem but I don't know why the gas would be boiling. Were you are high elevations? I once had liquid gas coming from the charcoal canister hose that runs back to the tank but that was at 8000 feet elevation on a nice day in the 70's* and running normal California gas which isn't really "normal".

I have a set of 30/30/30 rcv shafts that will be going in this week but I am also going to part time and 3:1 low range gears. I took delivery of the RCV's nearly a month ago and just broke a birf last week. Go figure!

They are a beautiful piece of work. I will spare you the story but I ended up also receiving a set of the Nitro Brand front chromoly axles because Low range off-road screwed up. So I had the opportunity to compare the rcv axles side by side with the Nitro's. It's my understanding that rcv makes the Nitro's so the birf's on each axle looks identicle but the inner shaft of the rcv has 30 splines at the birf, as you know, as opposed to the standard 24 coarse splines of the Nitro, and the rcv shaft was 2mm thicker which is visibly noticeable. I did not get the more expensive RCV's with 300m inner shafts. I read that the 300m is only about 15% stronger than standard 4340 and for the extra $300 I did not feel it was necessary.
 
Thanks Bald!

Did you get the RCV drive flange too? I saw an ad that said " not for street use" but can't figure out why. maybe just a standard disclaimer?

and not to open a can of worms, what 3:1set/ spool did you go with? Been looking at that change too, as to not be stranded "if" another birf breaks! embarrassing to have to bum a trailer ride! especially being the only cruiser there!~ :doh:
 
Since I'm going part time, I will use ARP hub studs and Aisin manual locking hubs but carry flanges as back ups.

The chromoly shafts are more elastic and a slightly "softer" material than oem axles and will wear faster. However, through an email, an RCV Rep told me they had been running their axles in a company vehicle (tow rig) and the shafts were always turning (sounds like a dodge) and with p120k miles on them, were still good to go.
I got my gears from Steve at EBI in B.C. He clams that his gears come from the same Japanese factory that Marlin gets his from. My part time spool is from Marks 4wd, I bought it NIB from a forum member.

I have considered running drivenplates with transfercase disconnected. This is how my Dodge 3/4 4x4 is set up. The tires always turn the alxles and the drive shaft but no one in the 80 series world ever does this.

With RCV shafts and Drive plates and ARP studs I'm thinking that your ring and pinion might become the "weak link". Not good. I'm hoping that the stock Aisin hubs will be my weakest point.
 
Well I guess that makes perfect sense that you'd have manual hubs (ie no drive flange) if you were going part time?! Guess I should pay a little more attention!

Maybe I ll save the money from the 4340 drive flange and get some manual hubs, since i am planning on doing that anyway!
 
Anyone have a part number for just the wheel speed sensor (passenger side)? Not the $500+ abs wiring kit etc that my search fu keeps coming up with?
Mine was destroyed when my birf decided it had had enough.
 
Your power loss does sound like fuel boiling and turning into vapor. Heat is added to the fuel as it passes through the fuel rail, is returned to the tank and then more heat added by the pump. The fuel continuously recirculates through the system. The boiling point varies depending on fuel contents and it's all mysterious because the refineries can basically dump anything they want in the fuel, but it can be anywhere from 130-160 F. When you added fuel from your subtank, you added cool fuel and the problem went away. The premium probably didn't have much to do with it, but a winter blend could, again it's all very mysterious what the refineries put into the gas. Premium (the word 'premium' is pure marketing BS, it's 'high octane fuel'). Anyhow, 'premium' is not helpful for a low compression engine, just a good way to gift extra money to the fuel manufacturers for no benefit to yourself.

I've thought about adding a fuel cooler for this very reason. In the summer my fuel boils on a fairly regular basis. Put your hand on the fuel tank when this is happening, it gets very hot.
 
However, through an email, an RCV Rep told me they had been running their axles in a company vehicle (tow rig) and the shafts were always turning (sounds like a dodge) and with p120k miles on them, were still good to go.

I assumed the issue was the birfield bell not being hard enough in the ball races to deal with daily driving wear.. shafts themselves should be fine right? Or are they running rcv cvs in that rig as well?

Anyhow, 'premium' is not helpful for a low compression engine, just a good way to gift extra money to the fuel manufacturers for no benefit to yourself.

I've thought about adding a fuel cooler for this very reason. In the summer my fuel boils on a fairly regular basis.

OP is probably running premium due to the supercharger?

Good idea on the fuel cooler though. I've dealt with boiling at altitude as well.

 
Yes. Premium( higher octane) as suggested for for supercharger.

And I was understanding that rcv has a lifetime warranty. My rig isn't a DD. Yet should last me forever?!
And I'll part time it eventually.
 
Yes. Premium( higher octane) as suggested for for supercharger.

And I was understanding that rcv has a lifetime warranty. My rig isn't a DD. Yet should last me forever?!
And I'll part time it eventually.

Ah, I missed the SC'd part. That raises the compression ratio effectively so premium makes sense. Supercharger with hotter engine bay even more heat put into the fuel.
 
I assumed the issue was the birfield bell not being hard enough in the ball races to deal with daily driving wear.. shafts themselves should be fine right? Or are they running rcv cvs in that rig as well?



OP is probably running premium due to the supercharger?

Good idea on the fuel cooler though. I've dealt with boiling at altitude as well.


Yes, RCV birfs.
 

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