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post #1 of (permalink) Old 02-13-2003, 03:29 PM Thread Starter
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Hard startup..

I've lived with it for long enough and would like to remedy it..
What I have is a 90 YJ with a 4.2L and a standard carb(no fancy bbd stuff)
It had a thermo choke on it before(that connects to the manifold) and it didn't work real well.It was pretty unpredictable..
So I put on a manual choke.
Works great when it is warm.
However, its very hard to startup.
What it usually requires is a closed choke, many many pumps of gas beforehand..and a heavy foot for the first 30 seconds or so after it is starts up.You have to constantly rev it up to keep it from dying for that 30 seconds to a minute.As I said after that it works fine.
What I'm wondering is why it would require so much gas before it will start.It's more than just a few taps [img]images/graemlins/smile.gif[/img]
Any help or suggestions on things to replace/adjust would be appreciated.
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post #2 of (permalink) Old 02-13-2003, 04:05 PM
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Re: Hard startup..

I would go back to the original choke. I bet your problem is the heater at the bottom of the intake. If you look down the carb throat (throttle open), at the bottom of the intake you will see a apx 3" round disk that looks like it has a bunch of short rods sticking up out of it. This is an electric hear riser. It helps to vaporize the gas with the engine cold. Without it working, the engine runs real bad until the water starts to warm up...no matter what you do with the choke.

Look under the manifold and you will see a heavy red wire coming from it. Follow the wire up to the fire wall. It should go to a standard 12 DC relay mounted on the firewall...about 8" from the brake booster. I bet the relay is bad or you have a blown fuse. It's real easy to troubleshoot with a voltmeter. I the relay is energizing with the engine cold and there is voltage going to the heat riser, then check the riser for an open. Fix it and I bet it will start and run a lot better. While your at it...loose the man choke.
post #3 of (permalink) Old 02-13-2003, 04:40 PM
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Re: Hard startup..

1. Have you dropped back to basics yet Joey?
2. Pull the air cleaner off the Carb when the engine's stone cold.
3. Look down into the throat of the carb.
4. Now pump the sccelerator linkage once.
5. Did you see any gas spray out the jets?
6. If not, then you've got to do something about those jets...
7. Now try to start the Jeep....
8. You say it's hard starting...
9. So, before it fires up...
10. Stop and pull the plugs.
11. Are they wet with gas?
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post #4 of (permalink) Old 02-18-2003, 10:10 PM Thread Starter
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Re: Hard startup..

sorry for the late reply.

The manifold heater switch doesn't have any wires going to it.I assuming this is because it had an engine fire in its past life, and the original carburetor was replaced with another carb (non computer controlled) and non of the sensors are hooked up.
I also believe it is used with an electric choke, but I have the manual choke now.
I could not get the thermo-electric choke unless it was warm to work at all, so I would prefer not to go back to it.
It is getting plenty of gas in each spray.
The plugs were not wet with gas.
Its not really hard starting, just hard to start up.
Could it be possible that gas is flowing back to the gas tank?
I discussed it with my dad, and he said that it sounds like the gas may be flowing back to the gas tank(he said usually diesels have check valves, but didn't know about jeeps).

Anything else you woudl like me to try?Hook up?
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post #5 of (permalink) Old 02-18-2003, 10:32 PM
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Re: Hard startup..

When was the last time you changed your sparkplugs and plug wires??? Just a thought...i know my 304 was like that for a while and when i changed them(albeit to an msd ignition and new plugs/wire) it fired right up!! just a thought!!! [img]images/graemlins/cool.gif[/img]
post #6 of (permalink) Old 02-18-2003, 10:56 PM Thread Starter
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Re: Hard startup..

Previous owner said he did a tune up.
Spark plugs look new, as do wires and cap.
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post #7 of (permalink) Old 02-19-2003, 02:35 PM Thread Starter
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Re: Hard startup..

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