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Unread 10-28-2013, 05:27 PM   #1
TMSquy
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1990 YJ Wrangler 
 
Join Date: Apr 2012
Location: Mertztown, Pennsylvania
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1989 yj 2.5 engine wont start or run

The jeep sat for awhile and I have worked around it for awhile. Here and there I tried diagnosing the problem. The injectors spraying fuel and it has spark. Timing chain was replaced recently and cylinder 1 at tdc has both valves shut. Distributor was recently replaced. The problem I'm having is fuel mixture isn't entering the combustion chamber. I tried pouring large quantities of gasoline into the intake manifold, crank it a few times, still no fuel to plugs. Anyone has any experience why? I tried replacing the egr valve and made no differrence. I unbolted to downpipe thinking a clogged exhaust isn't allowing flow, still no mixture to combustion chamber.

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Unread 10-28-2013, 05:31 PM   #2
Que89YJ
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1989 YJ Wrangler 
 
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The only way fuel can't get to the plugs if you are pouring fuel into the throttle body with the butterfly open is if something is blocking the throttle body.
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Unread 10-28-2013, 05:44 PM   #3
TMSquy
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Even if butterfly is open it doesn't help.
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Unread 10-28-2013, 07:19 PM   #4
Que89YJ
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How are you telling it fuel is getting to the cylinder?
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Unread 10-28-2013, 08:42 PM   #5
TMSquy
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Mixture isnt getting to the combustion chamber. Plugs bone dry. Spray either in the plug holes it attempts to fire.
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Unread 10-28-2013, 09:14 PM   #6
Que89YJ
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Then you need to pull the manifold and see where it's blocked. Something has nested in there while it was setting for such a long time. There it's no other reason for something from the throttle body not to get into the cylinder through the intake.
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Unread 10-28-2013, 11:55 PM   #7
TMSquy
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That's only option. Otherwise I would say the valves aren't seating
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Unread 10-29-2013, 06:53 AM   #8
Que89YJ
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1989 YJ Wrangler 
 
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The valves not opening.
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Unread 10-30-2013, 12:00 AM   #9
TMSquy
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I wonder why. I might pull the valve cover and see if I can find anything going on with the valvetrain
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Unread 10-30-2013, 08:09 AM   #10
Que89YJ
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Yes, if the valves are working then you need to pull the intake. Chances are that something set up house in the intake while it was setting.....maybe the exhaust too. Could be blocked stopping you from pushing any air.
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Unread 10-30-2013, 01:41 PM   #11
Siva283
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Wouldnt a compression test be a good idea? With the exception of bone dry spark plugs this sounds very similar to the issue I was having. If exhaust or intake is blocked wouldnt that mess up compression as well. Definitly easier than pulling the manifolds.
__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 10-30-2013, 02:34 PM   #12
Que89YJ
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1989 YJ Wrangler 
 
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Compression test and a bleed down test. I don't know how anything can get past the throttle plate. The more I think about it. Run the compression test. The bleed down kit should come with it. I would be real curious if something nested in the exhaust and its totally plugged. With the bleed down test it comes with a connector to put air in the cylinder. I would crack up the air pressure and see what comes out of the exhaust. Or have someone turn it over and stand at the tailpipe and see how much air is being pushed out.
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Unread 11-03-2013, 01:03 AM   #13
TMSquy
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Like I said, I unbolted the downpipe to see if something blocked the exhaust. Its on open manifold at the moment. Compression reads roughly 115 each cylinder. Tommorrow ill unholy the valve cover and see if the rockers are pushing the valves properly. That and or if something happened to the pushrods. The compression is a bit low, but not low enough to say it shouldn't run.
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