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Discussion Starter #1
I started a different thread saying that my suburban is hesitating, well that was what I gathered from my wife as she explained to me how it was driving. After having first hand experience I can say its not hesitating, just running really rough on idle, and rough while driving it as well. Almost like its not running on all cylinders. Its running so rough its shaking the truck. But there is no check engine light. Any thoughts??
 

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First you will want to check out the Fuel Pressure regulator. simply remove the intake from the throttle body and look down into the intake by opening the throttle body. If it is wet and smells very strongly of fuel you will need to replace the FPR.
Otherwise when was the last time it had a a tune up? just refresh my memory.
Also you may need to take a look at the Fuel Pressure itself, and also take a look at the IAC. And have intake gaskets or anything else been done on the truck?
 

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Discussion Starter #3
recently did plugs,wires,rotor,cap,fuel filter. it really made a difference after i did the fuel filter, i noticed because i did the filter a few days after i did the rest of the tune up. the truck sat for about 3 days before my wife drove it and noticed the problem.
 

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I would probably start with a fuel pressure test as suggested. I'd probably also put a scanner on it and see if there are any codes/pending codes even though the CEL hasn't come on.
 

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I would probably start with a fuel pressure test as suggested. I'd probably also put a scanner on it and see if there are any codes/pending codes even though the CEL hasn't come on.
X2 on the pending codes! i keep forgetting about pending codes!
 

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Have you made a second pass to make sure that all of your spark plug wires are on everything correctly? I always check them twice, 'cause there seems to always be one that just doesn't want to clip correctly.
 

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Discussion Starter #7
I will check the spark plug wires, thats a common sense thing i didnt even think of. And i did not know about the pending codes thing, good call there. I will probably take it to Autozone for the fuel pressure test and see about any codes. Thanks guys!
 

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Discussion Starter #8
I got a bunch of o2 sensor codes and a couple random misfire codes. thinking timing maybe?
 

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Maybe timing. You'll need a scanner that can read cam retard to check the timing though. Usually the only time timing becomes an issue is if you weren't very careful while changing the cap/rotor/distributor to make sure you get it back on right. Do you feel like you did that pretty carefully?

Which codes specifically did you get?

I might clear the codes, then test drive it and pull codes again to see if you get the same codes.

I recall one time I had a rough running engine with some O2 sensor codes and misfire codes and it turned out my positive battery cable was just loose.

Might also triple check your plug wires/plugs and make sure they look fine (no cracked insulators or anything).

I would probably still test the fuel pressure.
 

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Discussion Starter #10
This is what I learned today.....no spark at cylinder 3. switched plug 3 with plug 1 still no spark. switched wires and still no spark. So.........i ran out of time today to work on it, so tomorrow i am going to remove the distributor cap and rotor and check that out..........
 
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