I have a 1994 ford ranger splash 4L v6. And my truck has a miss. can anyone help me?

Question

my truck has a miss in it. when i drive up hills or need to give it just a little gas the miss starts. The miss feels like is doesn't want to go real good. it kind of jerks a little when it does this. now when i want the miss to go away, i give it full throttle (while driving) and the let back off the throttle. then it runs like it so post to (nice and smooth). then about 5 seconds later the miss is back.

what ever the problem is, it is gettin about 12 miles to the gallon when it got 18 before the miss started.

i have put new oxygen sensors in it (they go bad after about 8 months) , i have put a new fuel pressure regulator in it, a new mass air sensor, new spark plugs and wires, and a new fuel filter.

i have also put a flo master exaust on it, gutted the 2 converters, a k&n air filter, and a electric fan on it.

i have no clue what could be causing the miss. i have took it to so many people and they do not know what it is.

would anyone have any idea of what the problem may be?

Answer 1

Contrary to popular belief most engines will actually see a decrease in fuel economy with the removal of a catalytic coverter as the ecm attempts to improve emissions based on readings before and after the cats.  I think K&N air filters are something to fear I have seen several mass air flow sensors burn out as a result of the oil from the filter leaching onto the MAF filament.  With that said I have to assume that you aren't seeing a check engine light on your dash.  Try some simple things look for vacuum leaks (if you have a vacuum gauge I would be concerned about anything below 15 in hg), check your PCV valve it will s***w into your intake manifold.  I found a pretty good vacuum leak on a 96 ranger near the booster cylinder recently.  What kind of fuel pressures are you getting?  The symptoms seem to indicate lean condition (could be a result of those missing cats) or it could be a weak pump or kinked fuel line. If you are seeing a CEL and it is glowing steady I would buy a good Chilton manual for your vehicle and check you Throttle Position Sensor, Mass Air Flow sensor, Manifold Air Pressure sensor ohms for proper numbers.  If you are and it is flashing that would indicate a continous miss fire start by checking the coil it may not like high loads, then the distributor cap.  Are your plugs properly gapped?  Unfortunately without seeing the vehicle it is impossible to be sure of anything but these are the things I would look for first.  If you come up with more info post again.  Hope this helps some.

Answer 2

check your cat's they may be cloged...on my 95 Ram 1500 it wuld run the same way...until one day it didn't even start...took it to the shop and they took my exhaust off and it started right up...so if i were you check them out...if you can see through them you should be all set, if not then get new ones, or put a steel rod through it and get all that c**p out of there...until you need to go to emissions...good luck

Answer 3

Possible cracked cylinder head... very common on the the old 4.0