Hesitation/lack of power

Discussion in 'GM Powertrain' started by Slow1500, Aug 5, 2008.

  1. Slow1500

    Slow1500 Rockstar

    My mods as listed below if that need be known.

    My truck had run strong(for a 6er) for a while until about a week or two ago when I noticed a very slight "chugging" upon acceleration in the lower rpm range. It also lost what little pulling power I had in 4th and 5th gears....5th is flat out terrible now. The engine light was not on but I scanned it with my Hypertech. It found several codes..p0102, p0113, and another one I cant remember. Both of those relate to the maf sensor. Maf low input and iac temp is too low(shortened abbreviations). Would that indicate a bad maf? I only have 20k miles. Oh and now the engine light stays on. It kinda started when I started using Shell gas...have it tuned for premium. Anybody have any ideas?
  2. ct9a

    ct9a Epic Member 5+ Years 1000 Posts

    I don't think that using one brand of gas over another should make that much difference as long as you're using the same octane rating. I have heard that some companies have more/less detergents in their gas than others, so maybe. How "fine" tuned is it? I know with my Evo, I had some pinging issues with different brands of gas, but that was mostly due to how aggressive my timing tables were, alcohol injection fixed that problem.

    Also, is there a reason that you're tuning using premium? Higher octane doesn't always mean more hp or better mpg.
  3. Slow1500

    Slow1500 Rockstar

    Well, as I continued to modify my grand prix more and more(more boost, etc) it got to where I could tell a difference in like shell and chevron/texaco or citgo. It just did not run as good when I used shell. I do not know why, and did not think it would make a difference, either.

    As far as my truck goes, it's not fine tuned..just the generic "premium" fuel setting on my crap hypertech. I'm only going by their claim of having more power with the premium setting. I don't think there is anything wrong with the tune as it has run fine for a couple months with the "tune" installed. It's just recently when it started acting up. A few hours ago I reinstalled the factory pcm settings and drove it...same thing happening but with even less power....cant the be the tune
    Last edited: Aug 5, 2008
  4. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    Codes by themselves are rarely enough to pinpoint a bad component. A few ideas:

    1) I recently had a hesitation problem that turned out to be a loose battery connection. It should only take a few minutes to make sure power distribution and ground connections are good.

    2) Check for vacuum leaks/intake leaks that would allow air to bypass the MAF/IAT.

    3) Get a wiring diagram and check the MAF power supply and ground.

    4) IAT is usually a simple thermistor. Use an ohmmeter to make sure it is putting out a reasonable signal.

    5) If you clear the codes, do the same codes come back consistently?
  5. Slow1500

    Slow1500 Rockstar

    Well, I may have found the culprit... maf was unplugged. I don't know if it was something that I did when I unstalled the fipk or what. Maybe it worked its way loose because I didnt have the connector all the way pushed in. I will clear the codes tonight and see if it comes back. I do know that some power is back though. Guess it was right for me to think maf...just that it wasn't getting power. I should smack myself for it.
  6. PontiAddict

    PontiAddict Rockstar

    Haha! Well that'll do it for sure!

    Did you unplug it for a while after? Always is nice to clear out everything. Seems to do wonders for my truck, it starts running like a new truck again.
  7. Slow1500

    Slow1500 Rockstar

    lol, I just updated my tuning software..bout to test it out. I used to disconnect my battery on my grand prix every now and then to reset it. Like you said, it runs better afterward.
    But my truck is now DTC free and runs like a champ...a slow one, but still. ha

    Even though I found the problem, Thanks for the help, guys!

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