The truck is hard to start when cold. It will start every time but hesitates and stalls. It gets better each time you try to start it after about the third or fourth time it starts and runs good but has a very minor miss. You can watch the engine every 5 to 10 sec. it has that little miss. but the main problem with it i have is it misses while driving at a steady speed 50mph or so. also if you push the gas pedal down about half way it stumbles jerks misses then it stalls if i keep the gas pedal held at that position. If i let off the gas pedal it will stay idling then i can press the gas again and it will go but may have to do it once or 2 or 3 times before it will go again.I thought it was the tps sensor but i tested it it has 5 volts in, good ground and the output wire is around .5 volt or something at closed throttle and the voltage gradually increases as you open the throttle. I tried to make the tps malfunction by opening closing real fast then part throttling it about 50 times it would never give me any indication of defect. I have done alot of tests. There are no codes off or running. Any ideas or question please help me.
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Today I went out to check some more things. I first started with a test drive. The truck ran decent at first but had a small miss and was stumling every now and then. Then all of a sudden it really went to missing i thought i was not going to get it back. but i did. I left it running and idling with the engine barely idling and pulled one plug wire at a time. Found #4 and #5 Cylinder not hitting. Replaced plugs, wires, cap , button, air filter, fuel filter. Started up ran good but still had that miss and stumbling. I brought the truck back from the test drive and decided to check the timing. I disconnected the spout. found the line on the harmonic balancer and put some white out on it. Checked the timing with timing light. Well the mark is way over to the left side about straight across to the left. There is a metal plate over there with teeth but the timing marks look to be on the timing cover. so i rechecked the marks i had made and there is only 2 places to mark. There is a big notch and a small thin mark. The one i am going by is the small thin one. But my question is I believe the distributor is in wrong. or do i go by one of those marks on the plate to the left of the balancer or the timing marks on the timing cover. I just got this truck and it is my first ford. If you can help me i would appreciate your help Thanks Chris [/quote]
I just fix my truck with a somewhat simular problem.
It took me forever to figure it out but the firing order on the damn thing was wrong.
If you say that it's your first ford then I'm guessing that you haven't had it long.
Look up a spark plug wiring diagram and see if the wires are running to the right pistons.
If that ain't the problem, talk to the y-man or Dr. Bowtie.
Thanks Crazy i did check the firing order and it is correct unless it is one plug wire off. Another words the firing order is 153624 so i would have to put 4 at 2 and 2 at 6 and 6 at 3 another words rotate them all around one counter clockwise. I will check tomorrow.
I figured out what is wrong with my Truck. It has lost #1 and #6. It is the piston rings leaking. #1 takes way to long to build up about 7 compression strokes to get to about 110 lbs. #6 is the same way and i only have 120lbs on #s 2345. I put a little oil in the #1 cylinder and rechecked the compression it shot to 140lbs really fast around 2 compression stroke. Just letting everyone know before you go replacing parts with a miss symptom do a simple compression check first if it passes then you know it is not something major.