Piston Slap: The Last Afghani Trail to Blaze

Sajeev Mehta
by Sajeev Mehta
M.D.K. writes:

UNCLASSIFIED

I am currently at Bagram Airfield in Afghanistan where I will often find myself motoring around the Forward Operating Base (FOB) in one of the last generation Chevy Trailblazers. It is the straight six variety and it has undoubtedly led a difficult life. My requirements are few however…pretty much I need something that can do 25 miles an hour or so and not strand me on the other side of the airfield. As a bonus, the Trailblazer has a working AC and radio. What it doesn’t have is the ability to do 25 or so miles an hour regularly and get me back from the other side of the airfield.

Pressing the gas pedal beyond a few millimeters will get me stalling and/or backfiring. In general it sounds like it is running on 4 cylinders. It will surge and run normally for a second and then not. It seems to get worse the hotter it is (which is bad this time of year.) I took the damn thing to the motorpool and they told me I can turn it in and walk back if I don’t like it (the drawdown is a mother). I had to jump out and push it up the little ramp into our compound as it lacked the power to accomplish this feat on its own. As a Ford guy, I get some amusement out of this and taunting the Chevy fans but the fact is we could really use this thing. A bunch of us IT types have stared under the hood for some time and haven’t figured anything out. I am mechanically inclined (I’ve changed motors and stuff before) so I think I am the truck’s last hope.

This thing would be the nicest vehicle in our fleet by virtue of the AC if it would run. No, I can’t pull the damn codes as the PX is short on OBDII readers (and toilet paper) and there isn’t an Autozone within 7000 miles or so. If this may be something simple like a fuel filter or something I’m willing to get some parts sent over and crawl under myself. Just need to know if there are any common issues with these things. I don’t see any major mechanical issues like overheating or oil in the coolant. I appreciate your input.

UNCLASSIFIED

Sajeev answers:

So…no professional diagnostic tools, no basic Autozone diagnostic tools, and you’re the truck’s last hope? And an LS1-FTW swap is totally out of the question?

Checking the forums, it’s possible that a cam position actuator solenoid is the problem…and it will not throw a code. Or maybe a dirty throttle body, a clogged fuel filter or a dirty air filter. If the fuel you receive out there isn’t the highest quality, the filter is a major concern. And maybe your IT folks have electronic contact cleaner to clean the throttle body AND the mass air flow meter. But I’m all over the map: here’s my plan of action, given limited resources:

  1. Replace fuel filter, if other vehicles need regular filter changes out in the field.
  2. Shake out the air filter, bumping it on a large surface. Don’t bang it against a wall hard enough to damage it. I find large plastic garbage cans work well here.
  3. Clean the mass air flow meter and throttle body with electronic contact cleaner.
  4. Pull the spark plugs, clean and gap them.
  5. Replace the Cam Position Actuator Solenoid: even Amazon stocks them, maybe one of their drone prototypes can deliver it.

I will keep my fingers crossed that bad gas and dusty air are your only problems.

But no matter what, thank you for writing to us and thank you for your service.

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Sajeev Mehta
Sajeev Mehta

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  • Beerboy12 Beerboy12 on Jul 09, 2014

    Dirty fuel could be the cause of blocked injectors to, and, by now the plugs are fowled up. Best solution here is to get the vehicle into a shop or secure a Toyota Hi-Lux for your use.

  • Michael Peerson Michael Peerson on Jul 10, 2014

    Got a android device with bluetooth? If yes, Access to Wifi, if yes. Send me your address and I will mail you a ELM327. Or you can get one on Amazon for a few dollars. You need to snatch torque pro. If you need the 6 bucks .. I will help. Best I can do.

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