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Unread 09-22-2010, 11:36 AM   #1
04WJny
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1987 YJ Wrangler 
 
Join Date: Feb 2010
Location: Long Island, NY
Posts: 615
it cranks but wont start

I have a 87 wrangler 4.2L I6 stock. Ive been having trouble with my car stalling randomly for the past 2 weeks. Since it started stalling i have only let it warm up for 15 minutes and would drive it around the block sometimes stalling and sometimes not stalling. Today i went to turn it on and it would crank but not start. is it possible that it is the ignition switch or ignition module?

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2004 WJ I6 4.0L DD
1987 YJ I6 4.2L Weber 34 DGEC carb, 4in RC, Custom 1 inch BL,Custom Steering box skid, homemade rear bumper with tire carrier, 33x12.5x15 KM2's on
Cragar Soft 8's, and a few other things
In the process of putting in an 8.8, d30, 4.10's, SOA, and a homemade belly up skid
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Unread 09-22-2010, 12:12 PM   #2
monkeyhouse
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1997 ZJ 
 
Join Date: Sep 2009
Location: Cumberland, Maryland, Maryland
Posts: 3,151
Quote:
Originally Posted by 04WJny View Post
I have a 87 wrangler 4.2L I6 stock. Ive been having trouble with my car stalling randomly for the past 2 weeks. Since it started stalling i have only let it warm up for 15 minutes and would drive it around the block sometimes stalling and sometimes not stalling. Today i went to turn it on and it would crank but not start. is it possible that it is the ignition switch or ignition module?
it could be alot of things. Yo're gonna have to use some good troubleshooting to eliminate some things. I would start with the obvious, fuel. Make sure you are getting good flow to the carb, if not, check the filter and the pump. If that's all good, start with the ignition system...do you have a spark at the plugs? if not, work back, from the coil. that will get you started. I'm sure que will chime in here with some real good info on all those tricky electrical system issues.
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Unread 09-22-2010, 02:00 PM   #3
04WJny
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1987 YJ Wrangler 
 
Join Date: Feb 2010
Location: Long Island, NY
Posts: 615
stupid question. how do i know if i a have spark at the plugs? would it make the sound when i turn the key to start it when normally starting up before the engine starts?

i also noticed some unplugged vacuum lines. one of the six that are located on top of the engine in a 3x2 pattern right behind the intake and air filter cover. then i found another one located on the firewall 3 or 4 inches to the right of the battery(if you are facing the front of the car). it has a small blue solenoid device with a few wires attached
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2004 WJ I6 4.0L DD
1987 YJ I6 4.2L Weber 34 DGEC carb, 4in RC, Custom 1 inch BL,Custom Steering box skid, homemade rear bumper with tire carrier, 33x12.5x15 KM2's on
Cragar Soft 8's, and a few other things
In the process of putting in an 8.8, d30, 4.10's, SOA, and a homemade belly up skid
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Unread 09-22-2010, 02:12 PM   #4
monkeyhouse
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1997 ZJ 
 
Join Date: Sep 2009
Location: Cumberland, Maryland, Maryland
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Quote:
Originally Posted by 04WJny View Post
stupid question. how do i know if i a have spark at the plugs? would it make the sound when i turn the key to start it when normally starting up before the engine starts?

i also noticed some unplugged vacuum lines. one of the six that are located on top of the engine in a 3x2 pattern right behind the intake and air filter cover. then i found another one located on the firewall 3 or 4 inches to the right of the battery(if you are facing the front of the car). it has a small blue solenoid device with a few wires attached
you'll need a helper, have them crank the key while you watch a disconnected plug wire, just hold it near any groundable surface(the block is good)
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Unread 09-22-2010, 06:01 PM   #5
NonRubicon
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1990 YJ Wrangler 
 
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If you are completely stock (not Nuttered) the vacuum lines should be properly connected or you'll have performance issues. Here's the vacuum hose layout for the stock 4.2L



More info can be found here: Jeep Adventures Under the Hood

Another issue to check into is to make sure the Carter BBD carb jets are are not getting clogged.
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Unread 09-24-2010, 11:03 PM   #6
04WJny
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1987 YJ Wrangler 
 
Join Date: Feb 2010
Location: Long Island, NY
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I finally found the problem! with my neighbors help he checked the plugs and found that my plugs were not getting spark. I found out that a plug attached from the wire harness to the coil has eroded along with some bare wires at the entrance of the plug. Because of that the engine would stall. Secondly, i found that the top of the coil was dirty (covered in mud), stopping the electrical connection to the distributer causing my car not to start.
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2004 WJ I6 4.0L DD
1987 YJ I6 4.2L Weber 34 DGEC carb, 4in RC, Custom 1 inch BL,Custom Steering box skid, homemade rear bumper with tire carrier, 33x12.5x15 KM2's on
Cragar Soft 8's, and a few other things
In the process of putting in an 8.8, d30, 4.10's, SOA, and a homemade belly up skid
04WJny is offline   Reply With Quote
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