1996 Ford F150 Regular Cab Logo
Anonymous
Anonymous Posted on Aug 30, 2011
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4.9L straight six: Hard start when cold, black smoke, rough idle. New plug/wires, air/fuel filter, low pressure fuel pump primes then cuts off/no restriction in lines, Techron fuel injector treatment added. Could it be regulator or throttle position sensor?

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  • Anonymous Aug 30, 2011

    thanks, this is one of those now & then problems that's becoming more frequent. It happens more often on the front tank (low-pressure in-tank pump?) so i'd switch to the rear & it'd clear up. Now, it's happened on the rear too (grey/black smoke mix), afterwards low idle/ engine stall. Also, when it happens on the front tank there's poor acceleration/ auto trans shift points lag. Mechanic said probably poor electrical connection somewhere (EMC?) because its intermittent.

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  • Posted on Aug 30, 2011
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Considering the regulator has no effect on starting lets save that for later. You are surely getting too much fuel. Try unplugging the TPS (hot, cold, and startup). The computer will substitute a default value and you will notice a difference if it's as bad as you say.

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or try this link. What causes low rpm at the initial start of the engine Google Search
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