1984 Dodge D100

BJSIMS

MEMBER
1984 DODGE TRUCK

I just bought this truck from my great uncle, who bought it brand new in '84. The truck is in excellent condition. He was getting too old to drive. My question is. The engine runs good at idle, but whne you go to accelerate it hesitates. Sometimes backfires. If you coax the gas pedal alittle harder it will kick down to second gear and accelerate great, lots of power. It is that inbetween range of normal driving where I notice the problem.

I have changed spark plug wires, cap and rotor, checked firing order, replaced PCV vlave, and checked for vaccum leaks. The engine has 40,000 miles on it and it a rebuilt motor. Truck never smokes or gives any sign of fatigue. I haven't checked the spark plugs yet. And the carburetor looks like it could use a rebuild.

What would cause the hesitation and backfire at medium throttle?

Thanks,
Brian

2 Replies

KJB

MEMBER
4 POSTS

Hey brian

I have a 85 100 that I am restoring. And I have had similar problems in the past. This is what fixed mine. I suggest doing all of these things in this order to ensure quality mechanics and more enjoyment out of these great trucks.

1)make sure all of your cardurator screws are tight this will create a vacume leak.
2)use carb cleaner spray on the inside and outside to remove gum and varnish helps to free linkage and cleans the jets.
3)adjust air flow screw passenger side black cylindar. Turn it to the right til it closes. Then turn it back left 1to2 full turns. Do the same with the idle cam driver side behind the air flow sensor. This will be a spring screw that is hooked on the throttle body. Set till it hits the cam then back it off 1to 1.5 turns from plum. May have to pull back on the throttle and move the cam down by hand to get the screw to set on it before backing it out
4)change air filter
5)change fuel filter
6)change spark plugs, those new wires caps and rotar do nothing for you if your plugs are bad, plus this will aid in starting your truck and gas milage

1, 2, 3, 6 are the most important in my opinion. These are all things I did and my truck runs like a top you may have to adjust carbwith the climate and my setting may vary to yours do to location, I live in indiana. Good luck kris