Engine dies going uphill or highway speed

[jameschump]

Please someone help me. I have been wrestling with for a few days. So I have installed a new $400 carburetor and fuel filter (AMC 258 i6 / 4.2l liter) because engine would die when stopping. Now I am having an issue with the engine sputtering and then dies when going up hill or driving for about 5-10 minutes or so. I have gone through all the vacuum lines and they appear to be solid. I also changed the oil, plugs and wires as well. This issue never happened before and I cannot figure it out. Every time I think I have it and I take it for a test drive out on the road, I end up having to push it off to the side so I'm not blocking traffic. I have read through dozens of other forums, all saying the same things but none help. Thanks

 

[Sasquach]

So I'm guessing the problem existed prior to the new carb?
What do you think your fuel tank looks like? maybe rusty?
How bout your cat if still there? plugged cat?
Sounds like it's not getting fuel or can't exhaust but then how do you get it started again? does it need to cool down to start?
Get us some more info.

 

[dslywalker]

Fuel Filter in the right position
5/16 barb to carb and 1/4 to return line with 5/16 barb on top of 1/4
Floats not set right in carb.Faulty fuel lines plugged or kinked.There's a filter in the tank also that can cause trouble.
Blow some air thru your fuel lines not high pressure but around 40 pounds.
You can hook in a fuel pressure gage will help that you can see when your running down the road or have a helper read it.

 

[Sasquach]

Dsly, I thought you were a throttle body guy?

 

[jameschump]

So I'm guessing the problem existed prior to the new carb?
What do you think your fuel tank looks like? maybe rusty?
How bout your cat if still there? plugged cat?
Sounds like it's not getting fuel or can't exhaust but then how do you get it started again? does it need to cool down to start?
Get us some more info.

Thanks for getting back so quick! No, it never died on me while I was driving before, just when I stopped at a stop sign. Fuel tank looks good, the jeep is in great shape, litle rust. dont think cat is plugged, but could be wrong. Yes, I do need to let it cool down when it it dies on me, maybe like 5 minutes or so, but will die again shortly after, especially going up any kind of small or large incline.

 

[jameschump]

Fuel Filter in the right position
5/16 barb to carb and 1/4 to return line with 5/16 barb on top of 1/4
Floats not set right in carb.Faulty fuel lines plugged or kinked.There's a filter in the tank also that can cause trouble.
Blow some air thru your fuel lines not high pressure but around 40 pounds.
You can hook in a fuel pressure gage will help that you can see when your running down the road or have a helper read it.

Ah, I will have to check this tomorrow, I think that might not be in the right position, does that really matter what position it is in?. I will let you know, thanks.

 

[Sasquach]

Thanks for getting back so quick! No, it never died on me while I was driving before, just when I stopped at a stop sign. Fuel tank looks good, the jeep is in great shape, litle rust. dont think cat is plugged, but could be wrong. Yes, I do need to let it cool down when it it dies on me, maybe like 5 minutes or so, but will die again shortly after, especially going up any kind of small or large incline.

Could be a bad coil? when they go bad they can do this, not the uphill part. Wondering why you replaced the carb? for the symptoms you are curently having? sounds like not.
Dslywalker has a good point checking the fuel pickup in the tank although if you have to let it rest for 5 thats not gona be the case imho.
We'll get it though don't sweat.

 

[Sasquach]

Ah, I will have to check this tomorrow, I think that might not be in the right position, does that really matter what position it is in?. I will let you know, thanks.

Yes it does.

 

[dslywalker]

Dsly, I thought you were a throttle body guy?

i am, thats why i have fuel injection,no uphill battles

 

[jameschump]

Before I go too far with anything, does anyone know where I could find a good vacuum diagram for a AMC 258 i6 / 4.2l ? I'm finding poorly rigged lines from the previous owner, and get the feeling something is not in the right spot. Hard to tell because there is so many lines.

 

[dslywalker]

here's one for a Carter BBD on a 83.I have some more for around that year also.If your gonna strip part of the emissions theres some simpiliar onesclick twice on the space even thou it don't show anything

 

[Sasquach]

Before I go too far with anything, does anyone know where I could find a good vacuum diagram for a AMC 258 i6 / 4.2l ? I'm finding poorly rigged lines from the previous owner, and get the feeling something is not in the right spot. Hard to tell because there is so many lines.

Look above in the Docs right below the CJ banner, Dslywalker has the 81 year uploaded for you and if you dig around you might find your 83 but you will be pretty close with whats there.

 

[jameschump]

here's one for a Carter BBD on a 83.I have some more for around that year also.If your gonna strip part of the emissions theres some simpiliar onesclick twice on the space even thou it don't show anything

Thanks very much! I'm just going to carefully replace all the lines as well, they are getting old. I will let everyone know the turn out. Thanks again!

 

[priceg]

What is your fuel pressure?

 

[jameschump]

Ok, my CJ is testing my love. So I have gone through all of the vacuum lines (took a while), found a few minor leaks and replaced them. I replaced the ignition coil and the engine dies after running for about 5 to 10 minutes while driving like it has been doing. I have replaced the carb, plugs, wires and oil. The fuel pump was replaced recently but with my luck may be bad who knows at this point. I will mention that when I am able to start it up again, it idles high, not like it does when its first started. I need to check the pick up, hope I don't have to replace it. Is there anything I could be over looking? Thanks everyone.

 

[jameschump]

What is your fuel pressure?

I don't have a way to test it, what do you suggest?

 

[dslywalker]

They sell a fuel pressure test kit at the parts house that you can put on.Instructions are pretty strait forward in 10 different languages

 

[jameschump]

Ok, this is a list of things I have done so far:
-New Carb (not cheep)
-replaced/check all vacuum lines for leaks
-installed new fuel pump
-got a new gas cap
-installed new ign coil
-re changed oil (just felt like it)
-changed plugs and plug wires
-changes air filter


Starts up pretty smooth and runs great for about 5-10 minutes. Right before the engine starts to die, I notice it idles funny (real high like I'm stomp'n the gas). When it does die, I have to let it sit for about 10 minutes or so to get it to start back up again, and then will quickly die again, especially if going up any kind of incline or not on flat ground. Something's busted or not working correctly. The only thing I can thing of is the pickup in the fuel tank or the cat converter. Am I overlooking anything else before I start replace those parts? They arnt cheep. One other thing, I purchased CJ from a guy a few months ago who rarely drove it, just sat parked under is carport in hopes someone would buy it.

 

[Sasquach]

Did you ever make sure your fuel filter was installed correctly?
Sounds like possibly running out of fuel, not in your tank but the carb going dry witch would account for running lean right before it dies. If that it could be anywhere from your pick-up to your carb. Did you make sure your fuel lines are clear all the way to the tank? Concider cutting open your fuel filter and see how much has accumulated if any.
I know I mentioned your cat early on but I would not pursue that now with your added info.
I would also test your ecm and that leads me to...
If you do not own a service manual now is the time to get one, Everyone has there own preference but if I could only have one it would be the FSM hands down, I have an Ebay repint that I paid $80 for and it's paid for itself many times over. There are diagnostic flowcharts and directions how and what to test.
Anyone who owns a CJ needs to either be a competant mech. or learn to be one, You cannot just throw parts at it and hope for the best.

 

[jameschump]

Did you ever make sure your fuel filter was installed correctly?
Sounds like possibly running out of fuel, not in your tank but the carb going dry witch would account for running lean right before it dies. If that it could be anywhere from your pick-up to your carb. Did you make sure your fuel lines are clear all the way to the tank? Concider cutting open your fuel filter and see how much has accumulated if any.
I know I mentioned your cat early on but I would not pursue that now with your added info.
I would also test your ecm and that leads me to...
If you do not own a service manual now is the time to get one, Everyone has there own preference but if I could only have one it would be the FSM hands down, I have an Ebay repint that I paid $80 for and it's paid for itself many times over. There are diagnostic flowcharts and directions how and what to test.
Anyone who owns a CJ needs to either be a competant mech. or learn to be one, You cannot just throw parts at it and hope for the best.

Thanks again for your help. I did check the fuel filter (which is also new) and it is connected correctly. I checked through all the lines they are clear to the tank. I have not tested my ECM which I will do. I purchased a manual (Jeep CJ7 rebuilder's manual) but its not very helpful when dealing with fuel. I do not consider myself a pro by any means (which is why I posted this issue to begin with), but this problem is just something I have not run into before and am having a hard time figuring out.

Thanks again for all of your help, I will let you know when I figure out the issue.