1990 Jeep Wrangler Can't keep it running

Tiny
VTGREENBUTTERFLY
  • MEMBER
  • 1990 JEEP WRANGLER
  • 6 CYL
  • 4WD
  • MANUAL
  • 146,000 MILES
We just purchased this jeep. It ran when we were looking at it, and starts like a dream when you spray starter fluid in the carb, but wont stay running long enough for us to even drive it around the yard. We are new to Jeeps and have no idea where to start. Someone we know suggested replacing the whole carb but is that necessary?
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Tuesday, September 9th, 2008 AT 6:42 PM

8 Replies

Tiny
HUDDLESTON1
  • MEMBER
Is it getting gas to the carb, if not then it may be the fuel pump.
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Wednesday, June 17th, 2009 AT 4:35 PM
Tiny
AIRSOFTSOLDRECN9
  • MEMBER
The early Wranglers were actually had the intermediary throttle body injection to replace the problems and complexity with carburation.

Check to see if the pressure regulator is recieving fuel.
Verify the fuel pressure is approximatly 15-20 psi.

If you do not get fuel here trace the line back to the fuel filter and then to the fuel pump. Replace the fuel filter regardless, most likely it has not been unless the previous owner stated this. The fuel pump should hum with the ignition on ACC. If not check the fuse bus under the hood. It will be located in the powertrain distribution block in front of the battery.

If fuel is being recieved check the injector pintle for opening with a small 9v battery or an equivalent small dc source with between 9-12V @ 20mA>. You will need to disasemble the throttle body to gain access to the injector. The solenoid inside the injector should engage and disengage with a quiet click. If not it should be replaced. This may prove to be a bit much so feel free to take this to your local mechanic once you reach this point.
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Tuesday, June 30th, 2009 AT 10:47 PM
Tiny
HUDDLESTON1
  • MEMBER
This Jeep has a regular carb, external fuel pump, I have changed the pump and filter, and the carb is rebuilt and has been on there for almost a year. I think that the carb is bad, it only came with a 3 month warranty, so if I have to buy another one, it certainly won't be the same manufacture. I appeciate your reply.
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Wednesday, July 1st, 2009 AT 6:15 PM
Tiny
AIRSOFTSOLDRECN9
  • MEMBER
If this is the 258 then yes you are right it has a 2BBL carb as of 91 when they made the switch to the 242. Did you check the jets? Make sure that you do not have any vacuum leaks. It is all too common a small crack in the seal will form between the carb and the manifold. Disengage the choke linkage. You will want to adjust the mixture screws to full rich ( this should be all the way clockwise but I would like to know your carb model to be sure of this). Back them off 3 turns. Give it two solid pumps of the accelerator and verify that the power jets actually send fuel down the thoat of the carb.

Make sure you also have set the correct ignition timing (which I am also pretty sure is non adjustable on these but I might be wrong). Verify the plugs are clean of any soot and are gapped correctly.

How old is the fuel by the way.
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Wednesday, July 1st, 2009 AT 10:03 PM
Tiny
HUDDLESTON1
  • MEMBER
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Sunday, July 5th, 2009 AT 2:05 PM
Tiny
HUDDLESTON1
  • MEMBER
[/quote:3d7dbe39c0]

Will try the carb thing. It never has old gas in it because I drive it every day, I deliver mail in it. It usually starts cutting off after about two hours of running. I keep steering away from the carb because the one on it isn't even a year old, remanufactured. It came with a 3 month warranty, so that should tell me something! Right? Anyway, thanks, will try, and let you know.
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Sunday, July 5th, 2009 AT 2:15 PM
Tiny
AIRSOFTSOLDRECN9
  • MEMBER
"We just purchased this jeep. It ran when we were looking at it, and starts like a dream when you spray starter fluid in the carb, but wont stay running long enough for us to even drive it around the yard. We are new to Jeeps and have no idea where to start. Someone we know suggested replacing the whole carb but is that necessary?"

So you replaced the carb on it and it now cuts out while running after a fairly extended period of time.

Does it start to sputter and die?

If it is carburated then there is probably not an electric fuel pump most likely it is mechanical. But if it is electric I would check to make sure it is not overheating during operation.

Would you mind purchasing a vacuum guage and connect it in the vacuum control system. You should be able to place a tee in the line to the vacuum motor for the 4 wheel drive. Should be on the manifold. Run a line through the firewall so you can watch it while you are driving. When it is running at a hot idle see what the guage reads and if it fluctuates. When you start having a problem then definatly watch what the guage tells you.
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Sunday, July 5th, 2009 AT 10:50 PM
Tiny
HUDDLESTON1
  • MEMBER
[/quote:0872ec76cb]

Will try the carb thing. It never has old gas in it because I drive it every day, I deliver mail in it. It usually starts cutting off after about two hours of running. I keep steering away from the carb because the one on it isn't even a year old, remanufactured. It came with a 3 month warranty, so that should tell me something! Right? Anyway, thanks, will try, and let you know.[/Quote:0872ec76cb]

Jeep is fixed- changed the distributor, purrs like a kitten now.
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Tuesday, July 14th, 2009 AT 3:28 PM

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