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Suddenly missing

mcelwajy

Active Member
Joined
August 8, 2008
Messages
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City, State
Monroe, OH
Year, Model & Trim Level
1993 Eddie Bauer
OK, I am at a loss here.


Replaced my entire exhaust system, including removing the manifolds and adding a gasket to each side. No leaks, I finally have a quiet car :)


However,


Early last week I noticed a really bad miss when the motor is cold that only slightly improves once warmed up. I'm talking so bad that it bucks and bounces and almost stalls as I drive down the road until its warm.

I've done a full tuneup - new wires, plugs, air and oil filter, oil change, Rad. flush and t-stat replacement....I can't figure it out.


I have not checked that I am getting spark on all 6 cylinders though, so that is my step this weekend.


Once warm, it drives fine, but misses horribly at idle.


Any ideas? I cleaned the IAC Valve a while back, I really doubt it's dirty again. Can't seem to find any vacuum leaks - I did the "propane trick" to try and find one.

Also, worth noting - when I did the exhaust I replaced both O2 sensors. Now my exhaust smells EXTREMELY rich - to the point I wonder if its flammable....didn't smell like that before the exhaust repair...
 



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I would definitely check for spark, and make sure you ran the wires to the right plugs as well.
That's where I would start.
Good luck.
 






Cracked a plug or a wire is loose,take a look at all of the plug wires and plugs.:D
 






Cracked a plug or a wire is loose,take a look at all of the plug wires and plugs.:D



Assuming wires are routed correctly,

How would I have cracked a plug? This would be a new issue for me...I've never had that happen.

Based on the symptoms though, is it fair to say its an ignition problem more than likely?
 






OH good,

Now it continues even when its warmed up....any thoughts based on a new symptom?
 






Do a Cylinder Balance Test with Insulated Pliers. Pull off the Spark Plug Wires one at a time and verify that the Idle RPM Drops significantly. The weak cylinder will show up with little or no RPM Drop. This will at least isolate the issue to one particular cylinder.
 






Will do the balance test

BUT

Just figured something out....never checked my FPR. Pulled the vac line, looks dry. Got out a pen light, and down inside the line its soaking wet and the nipple on the FPR is wet....with gas. Think I just found my issue...agreed?
 






That might be the issue. Could be providing a Rich Condition. You could pinch the line to cut any fuel from being drawn in the Intake Manifold and see if the situation improves before you buy a new FPR.
 






the pressure regulator could most likely be the problem. we were just talking about this in fuels class yesterday. still check for cracked plugs though. i replaced the plugs on my buddies ranger yesterday because it ran pretty bad under load and the exhaust smelled rich. turned out the porcelain on his #6 plug was cracked. put new plugs in and it ran like a champ.
 


















Lucky me :) A few of the plugs had cracked insulators...pics to follow. Why would this have happened? The plugs are barely a year old? No overheating issues either....
 






Lucky me :) A few of the plugs had cracked insulators...pics to follow. Why would this have happened? The plugs are barely a year old? No overheating issues either....

over torquing them getting the socket on the plug at a slight angle could possibly do it
 






Well, you guys all know what spark plugs look like, so nevermind on the pics.


On a plus side, brand new set of plugs fixed it completely. What a relief....
 






Well, you guys all know what spark plugs look like, so nevermind on the pics.


On a plus side, brand new set of plugs fixed it completely. What a relief....

well thats good news
 






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