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Discussion Starter #1
OK...i finally had some time to mess with my 93 ruby after a few other repairs and reading up on past threads to try and find out what is causing it to run really rough sometimes. Here are the symptoms I have found:

The car runs GREAT after it has been sitting for a while (overnight).

Once the car gets up to normal running temp (190-210 degrees) things start to get rough. Accellerating, it sounds and feels like it is running out of gas...sputters quite a bit, knocks and then finally when you floor it, it will get over it and take off. It runs great once you get it up to speed and put cruise control on, but at the next stop light all the problems start over again.

When it starts running rough and you are sitting at a light, the car seems to "shake" a little bit as it stutters. Also, watching the digital voltage display, when running great it is up around 14.6-14.7, but when running rought at a standstill, it sits at about 14.2 and will dip to 13.1 (or lower with A/C on) and the dash lights/headlights also dim.

I thought it may have been old gas or too low of octane, but have filled it twice with 93 octane since taking it out of storage.

I don't know if this has anything to do with it, but the gas guage seems to be about a quater tank off (shows 3/4 full, but then can add 10-12 gallons of gas).

I know very little about engines, but i am trying to figure if this would be an optispark problem, battery problem alternator problem, fuel pump problem...or maybe something else i don't even know about.

Also, if it is an optispark issue, i know i should replace the water pump at the same time and see that you can find a rebuilt water pump online for quite a bit cheaper than new, but is it risky to buy rebuilt???

Any help would be great. I am hoping with all the people on here, someone has had these issues before and can help me out. I have only had the car since last October and have yet to get everything running well at the same time and can't wait!
 

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I had a similar problem. The car would sputter and ride rough but if I were to floor it the problems somewhat disapeared until I let off again. Well, it ended up being a spark plug wire that was laying on the manifold. It over heated and eventually burned through the wire's outer covering. I was getting a short in the wire which caused all my problems. When you have sputtering and rough riding and you have ruled out Gas its typically spark issues. Check your wires for any burnt spots and it may be a good idea to check your plugs too.
 

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Discussion Starter #3
I thought that may have been the problem when i got it out of storage, but the plugs and wires are brand new (maybe a month old or so and maybe 150 miles?) so i am almost positive that is the issue. That is why i am thinking optispark because that is the only part of the spark "equation" that has stayed the same.
 

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Discussion Starter #4
I have also tried the method of putting the car in neutral with the A/C ona nd then flooring it. The car pauses for maybe half a second and then kicks up to regular RPMs. I know this is the optispark test, but wanted to know if this could point to anything else.
 

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i agree, change the fuel filters out adn seafoam it. also, did you run fuel stabilizer thru it before storage?
 

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Discussion Starter #7
At very light throttle (almost just letting off the brake and VERY easy on the gas) it is ok...i still wouldn't call it normal. A bottle of stabilizer was added before storage and and it has probably been through 2.5 tanks since that tank-full.
 

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how old are your cattalyic converters ( horrible sp. I kno )
on my other car the exaust was crushed from a speed bump and caused terrible midrange response.
maby a clogged cat could do the same? just an idea.
 

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I would look at the fuel pressure regulator and the injectors. If it ends up being the optispark, play it safe and buy a new water pump.:thumbsup:
 

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I would look at the fuel pressure regulator and the injectors. If it ends up being the optispark, play it safe and buy a new water pump.:thumbsup:
:agree: i just had a similar problem with my 97 tahoe it would not get out of its own way until it got up to a good speed or got out of first gear and it was the water pump turns out the water pump being shot messes with the computer and will cause it to sort of shut down i put a new one in and it worked fine and as far as the sputtering that def sounds like it needs an injector or 2 :thumbsup:
 
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