1987 Wrangler YJ - JeepForum.com
 
LinkBack Thread Tools
post #1 of 4 Old 05-06-2010, 07:38 PM Thread Starter
87JeepYJdude
Registered User
1987 YJ Wrangler 
 
Join Date: May 2010
Location: Carlisle, PA
Posts: 3
1987 Wrangler YJ



Hey there, everyone. Glad to be on the forum. Brand new to the site - literally, just signed up.

Let me get right down to it. I just bought an '87 Wrangler YJ about a month ago. After a week, the motor let loose. She had a real bad knock. So out with the old, in with the "new".

I turned around and bought another motor, freshened it up and dropped it in.

I've changed over the intake/exhaust manifolds, various sensors, fuel pump, accessory system (went from a two belt setup to a serpentine system), clutch, flywheel (bought a new one for an '87) onto the "new" motor from the blown one.

The other day, I started it and it seemed to run pretty darn well for about 10-15 minutes and then it just died and won't restart now. I'm getting spark and fuel and it sounds like it wants to start, but won't.

Now, I've done a little homework on the block casting numbers and found that the "original" motor was from '81-'89. The "new" motor I put in is from '75-'79.

What, if any, differences are there between these two, seemingly, identical motors? Specifically, are the crankshafts and/or flywheels different in terms of being internally versus externally balanced? Any help that anyone could lend in terms of the minuscule differences between these two AMC 258's would be GREATLY appreciated. The more information, the better.

THANKS A MILLION, IN ADVANCE, EVERYONE.

87JeepYJdude is offline  
Sponsored Links
Advertisement
 
post #2 of 4 Old 05-06-2010, 08:10 PM
HARLEYX2
Registered User
1987 YJ Wrangler 
 
Join Date: Dec 2005
Location: Canton, Georgia
Posts: 515
When you went to a serpentine belt did you change the waterpump to a reverse rotation waterpump so it doesnt run hot?
HARLEYX2 is offline  
post #3 of 4 Old 05-06-2010, 08:33 PM Thread Starter
87JeepYJdude
Registered User
1987 YJ Wrangler 
 
Join Date: May 2010
Location: Carlisle, PA
Posts: 3
No. The water pump that came on the "new" motor was fairly new so we replaced the gasket and put it back on with the blown motor's pulley and fan clutch and all that. If it's a matter of the water pump. I have the blown motor out in the shed with a good water pump on it. Just swap them? The gauge was bouncing up and down when it was running, but I figured there were bubbles in the coolant system and I was going back and forth topping off the radiator and watching what it was doing. Like I said, after about 10 minutes or so it just cut out and won't restart now.
87JeepYJdude is offline  
post #4 of 4 Old 05-06-2010, 09:09 PM Thread Starter
87JeepYJdude
Registered User
1987 YJ Wrangler 
 
Join Date: May 2010
Location: Carlisle, PA
Posts: 3
I just looked the water pumps up on RockAuto. Crap!!! I didn't realize they were different.

So, basically, I have a reverse rotation pump with the standard rotation belt/pulley. Great...I hope I didn't waste another motor. I guess I'm going to swap the water pumps tomorrow, pull the spark plugs and do a compression test.

Seriously though, if it was only running for 10 minutes, is that enough to overheat that motor to the point of rendering it beat? It seemed like it was moving the coolant. I filled it up as much as possible before starting it and was able to get another gallon or so in it while it was running since everything was pretty much filling back up.
87JeepYJdude is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
new 1987 wrangler owner has questions PASKS YJ Wrangler Technical Forum 5 07-31-2009 07:22 PM
1987 2.5L Wrangler Ignition coil timbercrete YJ Wrangler Technical Forum 1 06-30-2008 05:59 PM
1987 Wrangler no spark mfw1fan24 YJ Wrangler Technical Forum 1 04-08-2004 06:29 AM
1987 Wrangler Horsepower Komo YJ Wrangler Technical Forum 6 01-02-2003 09:23 PM
1987 Wrangler for SALE jeepsaremything YJ Wrangler Technical Forum 0 06-29-2001 05:30 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome