engine runs rough?

Has the check engine light come on? Have you checked for vacuum leaks? Finally we should look at this guide it can help us fix it

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

The Check engine light has not came on.
Yes I have checked for vacuum leaks, and found none.
Last Tune Up- I don't drive it that much and it has been a little while, but it when this problem ocuurs when you first take off driving, it almost acts like when you shut it off and start it back up after the motor warms up - to me it seems like it is resetting the computer or something in the electronic system.
If it was drawing moisture in something, after it warms up and dries out, it don't seem to me like it would reset whatever it is doing; and to me when it seems like that is what it is doing - resetteing something.

I wonder if the temp sensor is the problem. If it sends a bad signal to the computer, the air / fuel mixture may be wrong at start up.

have put new plugs,egr,fuel filter,camshaft sinsor,air filter.checked injectors i have clicking sound at all of them,but i still have rough running at different speeds. A friend of mine said that it was the camshaft that needed replaced.I keep getting a check engine light and codes PO308,PO401.

I don't think you need a cam. One code is for a #8 cylender misfire. Have you checked the compression in that cylender? I realize you have already tuned it up.

As far as the other code, remove the EGR and make sure there is vacuum to it. Clean all carbon from it, and make sure the valve is seating properly.

Let me know what you find.
Joe

My F150 is running rough on a cold start. then seems to level out after the engine temp warms. It also has no power over 2k rpms. Getting on freeway if you push the gas the rpms rise but the truck slows, absolutly no power. If you easy into pedal you can reach high speed after a good distance. I took it to a parts store they pulled codes. Said miss fire on No. 3, so replaced plug and coil. No change in performance.

Have you checked fuel pump pressure? Also, I want you to check behind the throttle body. There is a large (aprox 3/8") vacuum hose with a 90 degree bend in it. Check to make sure it isn't broken or dry rotted. Also, I need to know if there are any other codes.

Let me know.

JOe

sounds like fuel pressure or injector probblem also have you changed the fuel filter also check the idle air control valve

2001 f150, v-8, 5.4, replaced coil on 7 because "misfire code". ran good for a few weeks. Light came back on, little shake at idle, shaking and sputtering while accelerating, loss hp. now have code "lean on 6,7,8. HOWEVER, it is running exactly the way it did when i had a misfire on 7. i was convinced i put the coil in wrong. but now it is a too lean code. I have cleaned mass air flow sensor, chwecked thuroughly for vacuum leaks, next im told i need to clean erg system. is that right? it cant be fuel issue because its only 6,7,8. what do you suggest next

Hi:
Even though you checked for vacuum leaks, I think that is the problem causing the lean mixture. I want you to check behind the throttle body (passanger side). There is a vacuum hose that has a 90 degree bend in it from the TB. They are known to dry rot and leak. If it was a misfire caused by a coil / ignition component, it would cause more of a rich mixture.

Let me know what you find. Also, if you have no luck with that, remove the coils that are recognized on the OBD. Check the boots that go on the plugs to make sure none of them are arcing through the sides onto the valve cover. That is another common problem.

Joe

Okay, my truck starts and runs just fine in park and neutral when I put it in reverse or drive it runs rough and has very little acceleration. it hard to get it to pick up speed it is like it is getting not enough fuel or to much. when coming to a stop it wants to shut off it is like the transmission is bogging it down. my main problem is not picking up speed. I took the catalytic converters off they where both plugged up and glowing red. thought maybe that would have fixed it it helped a little. any help would be appreciated. Thank you

It would be great if we could get a video of the problem so I can see whats up. For now I would say lets check the fuel pressure to make sure we are okay that.

Here is a guide to help you:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please let us know what you find.

Cheers, Ken

at any time the motor can go from running good to running very ruff.this could happen at a idol or at 60 mph. could run bad for days, then start running good all buy its self,and run good for weeks at a time.replaced plugs and wires air filtter used injector cleaner. none of this helped.

Have the truck scanned for codes, Autozone does it free, you can also try the wiggle test, open the hood and with the engine running, wiggles the connectors on the sensors, if it runs rough at some point, turn off the engine and seperate the connection, use contact cleaner, then die electric grease and put it back together. If any codes are stored, post here, see if you can also get any "freeze frame" Data.

is there spark plugs and wires on a 1998 ford f150 5.4 engine if so how do you get to them

Remove the Coil On Plug (COP). Remove the screw and the coil for each plug.

how difficult is it to change the plugs seems to be alot of stuff in the way i was wondering also does the EGR valve gradually go bad or is it all at once the engine has a miss in it at an idle when driving down the road it kinda chugs till you step on the gas then it quits till you let off the gas and go to get back on the gas it chugs again thanks

Engine Mechanical problem
1998 Ford F150 V8 Four Wheel Drive 160k miles

My 1998 ford f150 started running really rough today and the check engine light started flashing. I took it to have the error codes read was told that the following error codes registerd on the computer: p0307 cylinder misfire detected cylinder number 7, p0401 Egr system fault, and p1151 accelerator position sensor aps property malfunction. The worker at Autozone said it was either the Mass airflow sensor, the Egr valve, Bad spark pugs or Bad wires. From you experience what should I replace first and what is most likely causing the truck to run rough.?l

PO307 is cylinder misfire #7 ... this could be generated by the other fault
PO401 is EGR flow insufficient
P1151 is Lack of HO2S-21 Switch, Sensor Indicates Lean
check for vacuum leaks...check/clean MAF sensor ..check items listed below

70) DTC P0401

This DTC indicates self-test has detected insufficient EGR flow. Possible causes are:
EGR valve stuck closed.
EGR valve diaphragm leak.
EGR flow plugged or restricted.
Faulty EGR hose.
EVR VPWR circuit open.
EVR VPWR circuit to PCM open or shorted to PWR.
DPFEGR sensor VPWR circuit open.
Faulty DPFEGR sensor hoses.
Faulty DPFEGR sensor.
Faulty EGR VR solenoid.
Faulty PCM.
40) DTC P1130, P1150, P1131, P1151, P1132 Or P1152: HO2S Not Switching

DTCs P1131 and P1151 indicate air/fuel ratio is correcting rich for an overly lean condition. DTCs P1132 and P1152 indicate air/fuel ratio is correcting lean for an overly rich condition. DTCs P1130 and P1150 indicate fuel system has reached maximum compensation and HO2S is not switching at the adaptive limits. Possible causes are:
Fuel system malfunction.
EGR system malfunction.
Air intake or vacuum system leak.
Engine oil level too high.
Incorrect cam timing.
Restricted air cleaner.
Faulty PCV system.

My 1998 Ford F-150 v8 4.6L backfires on acceleration and is running rough. It has 175,000 miles and has never had a tune up.. I am taking it to a mechanic and would like to know what to expect so I won't get ripped off. What is the approx cost of a tune up and what is it they should be checking?

If it has never been tuned up, chances are that is the problem. Has the check engine light come on? As far as a tune up, I would estimate around 200.00. However, that can change based on where you live and labor rates.

I assure you, if the plugs are OEM with 175K on them, they have been done for a long time. They will cause a miss and backfire.

Let me know if you have other questions.

Joe

1998 Ford F-150 mileage: 78,786. My truck is an extended cab pick up truck, cruise, automatic transmission, power steering, power brakes (ABS in front). When the weather got cold here in Wisconsin, the truck started running rough when it first was started, but then smoothed out as it warmed up. This became more prevalent below ten degrees F. I knew the truck was due for a tune up and took it in. The garage told me that my spark plug wires were bad, probably original equipment, and they replaced the wires, plugs, cap, and rotor. Two days after I got it back, I had the same rough running problem when I started it and as I listened to it it seemed that the problems were similar to the choke sticking on an older carburetor type fuel system. I called the garage and made an appointment, but was not able to get the truck in before it quit running. We got a cold snap, I went out to start the truck, and it ran very rough for a short time and then quit. I tried several times over the next two days to start it, but it would not start. It would turn over fine, and it would try to fire, but just wouldn't go. It emitted a strong smell of raw gasoline and I had it towed to the garage. The garage had the truck for three days and called me up to tell me that they could find nothing wrong with it except that it was badly flooded. They told me they had to take the plugs out and dry them off and they had to change the oil. There was less then five hundred miles on the oil change. The mechanic stated that there was an extra quart of fluid in the crankcase and a strong smell of gas. He said that after he changed the oil they put the truck on a diagnostic computer and they could find nothing wrong except that the computer found gas fumes still present in the crankcase. I got the truck back last week and used it to drive to work on Friday and Saturday. Both days it still had symptoms of running rough when it was cold but would smooth out as it warmed up. Saturday I filled it with gas and my wife and I went out for dinner. The round trip to the restaurant was about twenty eight miles. The truck again ran rough until it warmed up, and seemed sluggish at city driving speed. The truck used a quarter tank of gas on the twenty eight mile trip. Can you tell me what might be wrong?

Your fuel pressure regulator is probably failing causing excessively high fuel pressure, which causes your engine to flood. This of course would result in extremely poor gas mileage.

This is my Dad's truck. It started running rough a couple weeks ago and has gotten worse. Replaced inline fuel filter, no help. Replaced both front OS2 sensors, no help. Mechanic tested catalytic converter and said that is not the problem. When you start out in 1st gear you can just barely push the gas pedal or it will bog down to nothing. Once into 4th gear it seems to run OK as long as it's a straightaway, if you hit a hill all power is lost. You get nothing when you give it gas. If you rev the engine in park it backfires. Any help is appreciated becuase he won't take it to the shop and I'm left trying to figure it out. He changed the plugs about 2 months ago.

If it is backfiring through the exhaust, I would start by looking for vacuum leaks. HAs the check engine light come on? Also, have you checked fuel pump pressures?

Backfire is coming from the engine and not the exhaust. Check engine light is on. I could take it and have it checked free on the machine but it is running so bad I'm afraid to drive it far. I was just reading about the MAS and I think I'll check that in the morning. I don't know how to check the fuel pump pressures. I will check for vacuum leaks tomorrow though. I know I can start out replacing basics; plugs, plug wires, etc. I know so little about auto repair. Would a vacuum leak cause the symptoms I described?

Yes, a vacuum leak can cause a backfire. It is common for it to happen. As far as the fuel pressure test, it is really easy. We have a video and directions on how to check it and the fuel pressure regulator. The only thing you will need is a fuel pressure gauge. Most parts stores will lend or rent them to you as well as a scanner. You may want to check that. As far as the fuel pressure, here are the directions and video. Watch the video and let me know if you have questions.

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

Joe