Could be a number of things.... a LITTLE bit of information would help in an arm chair diagnosis....like full model and serial number of the truck....is it gas or LPG......what engine does it have.....how many hours on it....what are the symptoms,does it do it in park or when in gear...hot or cold engine...???. Be a little more thorough in your expination of what and someone might be able to then tell you why....
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