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Unread 05-31-2013, 09:40 PM   #1
jguess1
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CJ7 engine will turnover but not start

I have a 1985 CJ7 with the 258 and it was running fine (well slow to start after setting) up until this weekend. Now it will not start at all. It will continue to turn over but just not start. It has an after market carb and I checked to see how dirty it was, but the carb is clean. It smells of gas when I pull the throttle. I also have an electric fuel pump. If you need pictures please let me know.

One thing I will say is when I would turn it off the engine recently it would sputter for about 2-5 seconds each time. I am not sure if that means something or not.


Thanks

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Unread 05-31-2013, 09:48 PM   #2
jeepwhore
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Could be a number of things. Sounds like fuel isnt the issue, can you hear your pump prime the system while you are turning it over?

Eliminating a fuel issue, the next thing to check is if you're getting spark.
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Unread 05-31-2013, 09:58 PM   #3
jguess1
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Yes I can hear the fuel prime when I turn the key. How do I check the spark issue?
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Unread 05-31-2013, 10:57 PM   #4
RenoF250
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My 85 is difficult to start after sitting and runs on. When it is difficult the only way it will start is if I hold the throttle to the floor then it will start to sputter and slowly come to life.

To check the spark just unplug a spark plug wire and stick an old spark plug or philips screw driver in it and then have someone turn it over and look for a spark. If you do the screwdriver do not pull it away until the engine stops turning. I learned that the hard way.
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Unread 05-31-2013, 11:34 PM   #5
titomars
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Quote:
Originally Posted by RenoF250 View Post
My 85 is difficult to start after sitting and runs on. When it is difficult the only way it will start is if I hold the throttle to the floor then it will start to sputter and slowly come to life.
This is also for the OP.
Hard starting hot where you have to hold the throttle open to get her to start is a flooding issue. there are a few possible reasons for this. here are a couple off the top of my head. Too much fuel pressure, float level too high, bad accelerator pump circuit, internal leak(s) inside the carb, choke adjustment (too rich). Depending on what carburetor you are running there are other things to consider too.
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Unread 06-01-2013, 01:05 AM   #6
RenoF250
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Quote:
Originally Posted by titomars View Post
This is also for the OP.
Hard starting hot where you have to hold the throttle open to get her to start is a flooding issue. there are a few possible reasons for this. here are a couple off the top of my head. Too much fuel pressure, float level too high, bad accelerator pump circuit, internal leak(s) inside the carb, choke adjustment (too rich). Depending on what carburetor you are running there are other things to consider too.
For me I think it is a choke problem because it is only on start-up sometimes when hot. I also wonder if the floats are not leaking letting residual pressure out into the intake. I have already rebuilt the carb and it is pretty worn out. My solution is to put the 4.0 I have in it.
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Unread 06-01-2013, 07:07 AM   #7
Matt1981CJ7
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The run-on after shutting off is called "dieseling".

Causes can be timing related, or a lean fuel mixture, idle too high, or just a sticky throttle plate that isn't closing all the way.

Based on your other symptoms, I'm going with timing.

Matt
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Unread 06-03-2013, 07:59 PM   #8
jguess1
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Quote:
Originally Posted by jeepwhore View Post
Could be a number of things. Sounds like fuel isnt the issue, can you hear your pump prime the system while you are turning it over?

Eliminating a fuel issue, the next thing to check is if you're getting spark.
So if I can hear the electric fuel pump prime when I turn the key to "on" and I am getting a spark when I try to start the engine. What would be the next thing to check? If you have any idea, how would you check them?

I only checked one plug. Should I check all six before moving on?
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Unread 06-03-2013, 08:17 PM   #9
BagusJeep
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To sort something like this out you need to be methodical.

1. Fuel delivery - nothing beats checking there is fuel by seeing it. Take the air cleaner off and look down the carb. With the pump on can you see any leakage into the throats? When you work the accelerator linkage do you see fuel squirting in there? And i mean a good squirt, not a dribble. If it has a choke at the top are the choke plates closed when it is cold? Take the fuel hose off at the carb inlet- do you get lots of petrol spurting out?

2. Spark - screwdrivers are not the best tool for this as you are not replicating the engine. Get an old spark plug, put it in the end of the lead and rest it on the block or manifold etc. When the engine turns over you should see a sharp blue yellow spark and hear a crack. This will be regular as the engine turns. Take out the spark plugs, are they clean? Do they smell strongly of fuel?

3. Look for manifold leaks, vacuum hoses that have dropped off etc.

4. Look at the distributor - is the vacuum hose connected?

5. Look at the fuse box - is that IGNLPS fuse intact? It feeds the computer on the 85 - unlikely to be blown but check anyway.
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Unread 06-03-2013, 08:26 PM   #10
tljones210
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Easiest step is to check vacuum hoses like above mentioned, if getting fuel to carb. $7 fix for me this weekend with exact symptoms.
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Unread 06-03-2013, 08:31 PM   #11
BagusJeep
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Bagusjeep was taking a long time to start until I replaced the vacuum hoses. they looked fine but in fact were crapoled.
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1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
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Unread 06-03-2013, 08:47 PM   #12
jguess1
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Thanks for the information. I will try these steps and get back to you.
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Unread 06-05-2013, 08:42 PM   #13
jguess1
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So it was definitely the vacuum hoses. I replaced them and it fired right up. Thanks for everyone's help/recommendations.
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Unread 06-05-2013, 09:27 PM   #14
LumpyGrits
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Quote:
Originally Posted by titomars View Post
This is also for the OP.
Hard starting hot where you have to hold the throttle open to get her to start is a flooding issue. there are a few possible reasons for this. here are a couple off the top of my head. Too much fuel pressure, float level too high, bad accelerator pump circuit, internal leak(s) inside the carb, choke adjustment (too rich). Depending on what carburetor you are running there are other things to consider too.
Hard start HOT is v'lock........
OP--Run a lead from the POS(+)side of your battery to the POS(+)side of your coil. NOW, see if it starts. IF it does you have ing switch issues which is common.
LG
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Unread 06-05-2013, 11:20 PM   #15
gurlcj
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Originally Posted by LumpyGrits View Post

Hard start HOT is v'lock........
OP--Run a lead from the POS(+)side of your battery to the POS(+)side of your coil. NOW, see if it starts. IF it does you have ing switch issues which is common.
LG
I'm having starting issues also. Running that lead is the only way I could get it to start! So, your saying it's an ignition switch gone bad? I've changed the coil Also, i get one spark and only one. Its when I let off the key. Still the switch I was leaning toward the pickup coil.
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