1995 Chevy Suburban Sputters

freddy0872freddy0872 Member Posts: 6
edited August 2014 in Chevrolet
I own a 1995 Chevy Suburban with a 7.4L V8 (454). We have had it for well over ten years now and have not had any serious problems with the truck. It runs great drives smooth for being a 8600 GVW 3/4ton. But recently it has been having an issue when the throttle is being pressed harder due to towing/hauling. What it does is if I get on the accelerator hard enough it will pick up whatever it is carrying and move! But after a few moments it will begin to sputter rather badly. Especially while it is idling. And due to the aftermarket exhaust I can hear it almost missing while driving down the highway and this occurs. After I shut the engine off and prime the fuel pump several times it usually goes away. Now ive had the fuel pump replaced and no change. The Ignition Controll Module went bed and that didnt fix it. I tried swapping out the MSD coil pack for the stock one and that didnt fix it either. Sometimes a code will pop up and I cannot remember the exact number but what the definition of the code was something along the lines of "Less than 2v at fuel pump". Now could this all be caused by a old and corroded wire or is there something else that i am missing? Any help would be greatly appreciated!
Again thank you in advance

Fred S.

Comments

  • kiawahkiawah Member Posts: 3,666
    You may want to track down electrical schematics for your vehicle. If you have a relay for the fuel pump, you may want to swap it out.
  • freddy0872freddy0872 Member Posts: 6
    hmm well i never would have thought of the relay. i figured if it kicked the fuel pump on it works. but why is it that when i up such a demand on the engine the relay would be the culprit? not that im doubting you in any way. im just confused when it comes to this matter. thanks for the help buddy! if you got any more insite or if anyone has any other ideas please feel free to let me know !

    Fred S.
  • kiawahkiawah Member Posts: 3,666
    I'm only going by your error code clue of low voltage at the pump. I had a '96 350 engine, but never had any fuel issues at all. I'm on the road, so don't have access to my old factory manuals. I don't even know that there is a relay in the circuit, but many vehicles have relays so suggested you could look in that area. I'm taking a stab in the dark, and suggesting to get yourself a set of electrical schematics, and check how power is controlled and delivered to the fuel pump.

    Within a relay, the points of the secondaries can electrically arc and pit, in which case they cause a resistance effectively dropping the voltage supplied out to the pump.

    Your symptoms sound like fuel starvation, which would normally suggest a fuel pump, but you've already replaced that. Is there a fuel filter on that model which might be clogged?
  • freddy0872freddy0872 Member Posts: 6
    Yes there is a fuel filter and i have replaced it a maybe a year or so ago when i started noticing this issue. Im going to go and print out the wiring diagrams and check to see what exactly is going on. Thank you very much! Ive gotten alot more help on here than i got going into Auto Zone or somewhere like that!
    Thanks

    Fred S.
  • apeluvstiggerapeluvstigger Member Posts: 1
    I ran out of gas in my suburban and now even after I put gas in it we cant get it to start.I am wondering if there is a reset switch because it is fuel injected. it has a 454 engine, or if any one has had this problem please help. :cry:
  • hyeddlemanhyeddleman Member Posts: 1
    Did you ever get your problem fixed? I have the same and don't know what to do?
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