Does anyone have any idea why my 6cyl. '99 ford ranger (manual transmission) seems to buck a lot coming off a dead stop in first gear (and this is the key) when I have about a quarter tank of gas or less. It does not buck with a full tank or anything above half full. Also, I’ve been driving stick for 16 yrs. It’s not operator error. Any thoughts would be greatly appreciated.
The fuel pump pickup tube may have been picking up loose debris in the bottom of the tank and is covering the strain sock causing a fuel flow interruption.
A quarter tank of fuel is going to slosh around a lot more than a full tank and may be enough to move the debris or (possibly water) toward the pickup sock.
I know this may seem too simple, but have you ever had the fuel filter replaced?
Then check the three musts: fuel, air and spark because this sounds like a problem with the basics as opposed to something computerised.
Other then that, you just can’t beat these types of Fords. I have an Explorer with 225,000 miles and it still runs like new. I will be tradeing in my Wife’s GM Jimmy (100,000 miles) for another Explorer - the GM has been in the shop several times a year.
I also suspect fuel contamination because the tank liner of my 87 Subaru deteriorated and flaked off in white particles, repeatedly clogging the fuel filter. The result was bucking from fuel starvation due to fuel filter clogging, during periods of high fuel demand such as acceleration, high speed and going uphill. Have the fuel filter replaced, have the old one saved and inspected – white particles may be difficult to see if the filter itself is white. To solve the problem I had to have the tank removed and steam cleaned ($600) … runs fine now. If you have been using oxygenated fuel, it might be that attacks certain tank liner plating – my 87 lived through Anchorage’s 1992-2004 period of oxy-fuels. There are also problems with diesel, see http://www.finishing.com/442/19.shtml
About how much would it be to replace the fuel filter? Also, I have noticed a lack of power/acceleration going up a particularly steep hill, but generally speaking the problem only occurs when starting from a dead stop in first gear. After that it’s smooth sailing to fifth.
Thanks for everyone’s advice. Any further consideration is much appreciated.