Uphill Battle

Uphill Battle
M

MDJEEPER

Senior Jeeper
Posts
549
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Location
Calvert County, Southern Maryland
Vehicle(s)
1986 Jeep CJ

Mostly stock, 258 c.i.d., T-176 tranny, Dana 30 front, AMC 20 rear, Dana 300 t-case, 31x10.50 tires, 2 inch body lift
For several months I have been trying to figure out why my project runs out of power going uphill...I mean lack of power as in cannot hold 60 mph in 4th gear. So far, I have replaced all of the ignition components, the fuel filter, and most recently tried the Nutter. Everything has made the engine run better, though not solving the lack of power issue.

Well, today I have a new symptom...I've now got a bad sputter going uphill on the highway!! And, it ONLY happens when going uphill! Just to be sure of this, I went WOT in several locations on flat ground without similar problems.

This may only be coincidence, but today is also the first 90+ degree day we've had here in the Mid Atlantic.

What do you think? Fuel pump? Internal carb problems? :wtf:
 
MDJEEPER said:
For several months I have been trying to figure out why my project runs out of power going uphill...I mean lack of power as in cannot hold 60 mph in 4th gear. So far, I have replaced all of the ignition components, the fuel filter, and most recently tried the Nutter. Everything has made the engine run better, though not solving the lack of power issue.

Well, today I have a new symptom...I've now got a bad sputter going uphill on the highway!! And, it ONLY happens when going uphill! Just to be sure of this, I went WOT in several locations on flat ground without similar problems.

This may only be coincidence, but today is also the first 90+ degree day we've had here in the Mid Atlantic.

What do you think? Fuel pump? Internal carb problems? :wtf:
Click to expand...
I'd take a look at the floats in the carb, and see if they are fuel soaked. That might cause the truck to run too rich, causing a sputter on a hill.

Or look at the spark plug wires. The angle of the hill may be causing them to move enough to short out, again causing a sputter.
 
I would look into the carb itself if you have the wonderful Carter BBD carb. I'm debating what to do as I have the same problem. The carb does not fuel properly. The carb is such a P.O.S. that it can't justify in my book spending any real money to fix, better to just replace with the Motorcraft and be done with it.
 
83NellyBell said:
I would look into the carb itself if you have the wonderful Carter BBD carb. I'm debating what to do as I have the same problem. The carb does not fuel properly. The carb is such a P.O.S. that it can't justify in my book spending any real money to fix, better to just replace with the Motorcraft and be done with it.
Click to expand...
Easy 83, the BBD is a great carb considering its design is 30 yrs old. What gets overlooked the most are the venturi metering holes. those dudes are .0250 of an inch. A pecker nat turd will stop them up. Kits are around $15 and their is plenty of reference material on this site to get you through an overhaul. That is all, out
 
83NellyBell said:
I would look into the carb itself if you have the wonderful Carter BBD carb. I'm debating what to do as I have the same problem. The carb does not fuel properly. The carb is such a P.O.S. that it can't justify in my book spending any real money to fix, better to just replace with the Motorcraft and be done with it.
Click to expand...

I'm with you. They were an acceptable carb back in the day, when they were new, but fooling with them now isn't worth the effort. Their inefficent, and temprmental, and they have done their work. I have several of them sitting in a bucket that will probably never see action again, at least not on my Jeeps. I go right to a Weber.
 
I found that keeping the Carter clean netted me a great running carb. I would venture and say that your might have a very low float level and up hill allows the float to drop down evem more and causes partial loss of fule and sputtering. You need to pull the carb and check the float levels. you also might have a flaot that has a leak in it and is dropping down.
 
My uneducated guess would be either the float or gas tank. These are the only two places where fuel actually changes position when going from level to uphill or downhill. I mention the gas tank since you said the PO replaced it ??? Of course, increasing the load on the Jeep by going uphill could be showing signs of something else. Easy to see if it's the load by towing something or loading it down with weight.
 
Lots of great ideas, thanks!!

What about the fact the loss of power got worse and it developed this sputter on a really hot day? Just coincidence??

Also, does everyone think it is NOT the fuel pump??

Oh, and yes I still have a BBD carb.
 
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Any chance you're getting a little vapor lock goin on there? Do you have the proper fuel filter and return line hooked up?
 
Well, let's start by getting that filter in the right posissition. Loosten the fittings and twist the filter so that the carb feed line is on the bottom, and the return line is directly over the top of it like an over under shotgun barrel. Check to be sure the lines are in good condition and not cracked anywhere.
 
Mechanic told me once when my BBD was acting up.He said the carb would leak internally between the bowls inside.This was because the BBD was famous for warping inside overtime.Gas would flow from one side to the other prematurely and and make it miss.He lapped mine smooth again and it worked.He said to get another fuel system before it gave out again.
Tha's how I wound up with the Howell system.I know the carb worked after he got done with it and I never tore it apart when I took it off to see what he was talking about.Thats was 12 years ago so pulling from my old data bank which could be wrong but thought I'd throw it in there.
Mike
 
coldwater said:
Well, let's start by getting that filter in the right posissition. Loosten the fittings and twist the filter so that the carb feed line is on the bottom, and the return line is directly over the top of it like an over under shotgun barrel. Check to be sure the lines are in good condition and not cracked anywhere.
Click to expand...

Roger. Over/under shotgun. Got it. I also noticed that the line I've got running between the filter and the carb is 1/4" rather than 5/16". Not much of a difference, but I will fix that too.

What size hose is the return line supposed to be?
 
dslywalker said:
Mechanic told me once when my BBD was acting up.He said the carb would leak internally between the bowls inside.This was because the BBD was famous for warping inside overtime.Gas would flow from one side to the other prematurely and and make it miss.He lapped mine smooth again and it worked.He said to get another fuel system before it gave out again.
Tha's how I wound up with the Howell system.I know the carb worked after he got done with it and I never tore it apart when I took it off to see what he was talking about.Thats was 12 years ago so pulling from my old data bank which could be wrong but thought I'd throw it in there.
Mike
Click to expand...

Yes, it would be great to know!
 
5/16 will be fine. That may or may not help, but eliminating problems as we find them means that sooner or later, you'll find the problem, and a string of potential issues will have been dealt with.
 
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