Fast crank no start - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 11-03-2013, 08:06 PM   #1
Newb
 
Join Date: Nov 2013
Posts: 2
Fast crank no start

Need a little help here. I have a 1989 Jeep wrangler with a 4.2 straight six. The starter cranks the engine fast, I have a good spark and compression is at 150 PSI but the engine wont fire.
I looked at the rockers and they were moving so I am guessing the timing chain is ok...
I tried priming it with a capful of gas to the carb but it only fired once then began to turn fast again. I have a mechanical fuel pump.
Any ideas?

FlatBroke is offline   Quote
Old 11-03-2013, 08:17 PM   #2
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,922
probably either not getting gas or have a vacuum leak

harleydragon is online now   Quote
Old 11-03-2013, 08:42 PM   #3
kik
Jeeper
 
kik's Avatar
 
Join Date: Dec 2008
Posts: 4,950
Images: 1
If you're getting spark I would take another look at the fuel. It's possible your fuel pump is bad or you might just have a clogged filter. You can disconnect the line and see if fuel is pushing through. The first, easiest and least expensive thing to do is to first replace the fuel filter. If the problem continues, check the fuel pump. If that's functioning properly it could be the carb. itself, especially if it's original. I'm not understanding exactly what you mean by "turning fast". Are you trying to say that the starter is turning the engine the way it's supposed to?
kik is offline   Quote
Old 11-04-2013, 11:54 AM   #4
Jeeper
 
tchoberg's Avatar
 
Join Date: Oct 2011
Location: Mountain Center, CA
Posts: 89
Take off the air cleaner and try some priming the engine with starting fluid or with a SMALL amount of gas. If it starts and tries to run you KNOW the problem is fuel related. Then check out the fuel delivery system before throwing money at it; fuel filter, fuel pump, gas lines to the carb and to the fuel tank for damage, fuel tank, and etc. If it doesn't try to start, look at the ignition system.
__________________
If it ain't broke, don't fix it - Don't worry, something will break soon enough for you to fix!
tchoberg is offline   Quote
Old 11-04-2013, 03:50 PM   #5
Founder, ThumbJeeps

WF Supporting Member
 
sevenservices's Avatar
 
Join Date: Sep 2009
Location: Mid-Michigan/Thumb
Posts: 3,952
The only time I've seen similar on an I6 was when the pickup coil on the distributor was bad. It would still spark, but not enough at the right time to fire.

You know, you only need compression, spark and gas. You should be good w/those. I would take a stab at that pickup coil. If I remember right they are only about $13-$15

Or, you could have water/condensation in the gas. Crank it over for a few, pull plugs and look for small droplets on the plugs. Gas spreads evenly, water forms droplets.
__________________
-Chris
Founder, ThumbJeeps


1994 Wrangler YJ I6 4.0 H/O Auto 3 spd. 4" RC (33x12.5) (15x8) 3:54 Gears
sevenservices is offline   Quote
Old 11-04-2013, 05:13 PM   #6
Jeeper
 
Redrider94's Avatar
 
Join Date: Aug 2010
Posts: 657
Have you checked to see if it jumped time, timing chain may have jumped a few teeth.
Redrider94 is offline   Quote
Old 11-04-2013, 05:27 PM   #7
Jeeper
 
1987Wrangler YJ's Avatar
 
Join Date: Jun 2013
Posts: 568
You might not be getting the initial squirt of fuel
1987Wrangler YJ is offline   Quote
Old 11-04-2013, 06:54 PM   #8
Jeeper
 
Join Date: Feb 2011
Posts: 78
timing,check distributor !
wreck999 is offline   Quote
Old 11-04-2013, 10:02 PM   #9
Newb
 
Join Date: Nov 2013
Posts: 2
Fast crank no start

thanks for the input guys. I replaced the fuel filter and the fuel pump is working fine. I will check the timing chain to see if it skipped a few teeth. Never thought of that since I saw the rocker arms moving. Forgot to mention I got rid of the stock carburetor and replaced it with a Weber two stage.
I replaced all plugs rotor and distributer cap.
FlatBroke is offline   Quote
Old 11-05-2013, 11:48 AM   #10
Jeeper
 
tchoberg's Avatar
 
Join Date: Oct 2011
Location: Mountain Center, CA
Posts: 89
Did you try priming it yet??????????

__________________
If it ain't broke, don't fix it - Don't worry, something will break soon enough for you to fix!
tchoberg is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not 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 Off
Refbacks are Off




Download our Mobile App

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 12:54 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC