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  1. #1

    Exclamation I need hlep! ~ 1991 K1500

    My friend has a 1991 K1500 5.7 V8 4WD, and he has a few questions:

    1. I have a 22in cherry bomb glasspack dumped before the rear axle, but its not that loud and dosent sound that good to me, should i get headers to make it louder, or should i true dual the the stock y-pipe to make it sound better, or both? (i like the sound of a cherybomb vortex and i can get it in a dual inlet/dual outlet if needed)

    2. I also have a problem with power and fuel econ., she just dosent have the giddy-up-n-go power i want nor the fuel economy, i put a K&N replacement filter on it and removed the stock muffler and replaced it with a glasspack (as stated in the first question) to try to get her to breathe a little better but i didn't really see much of a change, what can i do to improve the performance of my Chevy without losing fuel economy?

    I am on a budget but im not looking to buy everything by next week so any suggestions on my truck would be greatly appreciated!
    2003 Chevy 1500 5.3l VORTEC

  2. #2
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    Without a little more information it is hard to say. How many miles do the truck have on it? If the mileage is high a compression check might be in order. How about tire size? Is the truck lifted, does he run off road tires and have there been any modifications to the drive train? A lifted truck with big tires will hurt your fuel economy. Any thing that impedes the wheels from turning is going to degrade efficiency. Brake drag, under inflated tires are small contributors but together can be costly.

    I am not big on parts swapping; old does not mean worn out. But check the resistance in your plug wires, inspect the plug wires, distributor cap, and rotor. If the engine is not running the factory plugs or if they need changing, that would be one of the first steps. Look for a leak on vacuum lines and consider changing the fuel filter if it has been a while. I was blow away by the crap that came out of my last one. Can of seafoam or two can make even a Ford run better. Well, that might be a stretch but cleaning out the crud can hurt any.

    Headers are up to you. I had a factory 2 into 1 exhaust and I changed the muffler to a flow master 2 in 2 out. I like the sound but it is not what I would call loud. Assuming the cat is still on there you can check the exhaust pressure to see if there is any blockage. That would be low on my priority list though. Depending how long he has had the truck, verify the CEL is working. I have seen posts where guys have found out that the truck they purchased used was later found to be missing the bulb in the CEL. Could have been a factory oversight. Or, more likely, a dishonest bastard was somewhere in the trucks past.
    86 911 Porsche Carrera
    98 K1500 Suburban LT
    2012 Nissan Leaf

    ​General Motors.
    Because life is too short to drive a Ford

  3. #3
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    My favorite $10.00 fix is cleaning the throttle body, and MAF sensor. Autozone has the CRC brand of MAF cleaner and throttle body cleaner. My 01 S10 was running horrible a couple weeks ago, so I pulled the throttle body off COMPLETELY and cleaned it. Cleaned the MAF, and also removed the EGR valve and cleaned it and found that it was completely stuck shut! No check engine lights were on either, the truck runs like glass now.

  4. #4

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    Quote Originally Posted by Caddiac View Post
    Can of Seafoam or two can make even a Ford run better. Well, that might be a stretch but cleaning out the crud can't hurt any.
    Seafoam is pretty impressive how much crud it can clean out, I used one can in the gas and another in the vacuum system. It got rid of a lot of grime, Truck saw about 1mpg better gas economy.
    Thanks,
    J. Myles Gardner

    1998 Chevy K1500 Z71
    LT285/70R17 Hankook Dynapro ATM- 33"
    Monroe Reflex Shocks
    Rear Air Shock Helpers
    CLIFFORD 3.3X Security with Remote Start and PASSLOCK BYPASS:happy:
    Diamond Plate Toolbox
    Adaptive One Brakes
    :sign0144:

  5. #5

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    How do I put it in the vacuum system?

  6. #6
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    Suck the whole bottle through the brake booster line. You have to pull it out when the engine sounds like it is going to choke down and then ram it home again until it is all gone. Then shut it down and let it sit in there. The label tells you how long but some guys on here have reported going for as long as 4 hours before starting it up. When you do start it up, drive it hard until it stops smoking. I basically floored it every time I took off from a light. It looked like the truck was on fire there was so much smoke!

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