engine runs rough?

Check your fuel pressure and then comeback with the readings we start here.

I am mechanically inclined but where to I hook it up at? Do I need to do before the fuel filter or does it matter just incase my filter is the problem.

pressure was at 31 or 32 psi. depending on the marks between. also I did your test on the fuel pressure regulator and that checked out. Now when I turn the key the pressure gauge goes up but not to the 30 range. And when I rev it up the gauge goes up 3 or 4 psi.

When you turn key to run the fuel pressure should be 35-45psi and engine running should read 28-45psi

Sounds like the fuel pump is weak

does it matter that I have a dual tank? What are the odds of both being weak? Is that common? It could be my gauge also. Since when I turn on the key the gauge doesnt move at all. And I tried it on my other newer vehicle and it has a new fuel pump and same results.

Check the available voltage on both fuel pumps connector-could be a voltage drop problem.

i have a 5.8 engine...the distributor recently shorted out and had to be replaced. i also had a major tune up. the engine had never ran rough before this. it will run rough when cold and drop about 800 rpm every couple seconds. it seems worse during acceleration. my mechanic tested all of the cylinders and says everything is as it should. he ran a fuel injection cleaning. problem still there. He says fuel pressure is good and all electrical is working. Could you please help

sounds like engine misfire. if the plugs and wires are ok then its possible the distributor is faulty.

the mechanic checked spark on all of the wires and plugs and said they are all firing. the computer is giving no trouble codes. the rough running seems to get better after about 15 minutes when the truck has really warmed up

i hate to say i doubt your mechanic but it seems as though it has to be a igniton breakdown. he should be able to find the cylinder. possibly a cracked spark plug by accident?

went to work, ran smooth, but when i got off work, it ran rough. could this be an issue with the valve push rod? if so, do you know aprox how much it cost to repair or is it something a novice can do? Thank you

if it was a pushrod the vehicle would really run bad and you woudl hear a ticking/klanking noise.

if it was the pushrod its very easy to replace.

just take off valve cover, loosen rocker arm, rotate to side and pull out the pushrod.

be a bit more descriptive if you want to know whats wrong.

hello. my truck runs a bit rough on idle and hesitates and misses under load. im in the process of checking ignition timing and have tried to locate a spout connector but no joy. the timing light shows its either way off or somethings wrong. how do i adjust the ignition timing? ive checked the distibutor and rotor everything is relitivly new from previous owner.

well ive timed the ignition and replaced plugs cap rotor and checked leads. cylindr 2 is not working. the plug is sooted and dry. im thinking it may be an injector and hopefully not rings. the engine does not smoke at all.

are injectors a common problem on these trucks?

Hello. I have a 1993 Ford F-150 4x4, Inline 6-cylinder engine, stick shift with 218,000 miles. The truck does have dual fuel tanks.

Symptoms: Smell gasoline, quits when started first time (unless I kick the accelerator quick a couple of times), rough idle, and "jumps" or surges when you drive her. The idle is so rough you can hear it when it is idling. Last, I smell exhaust (and smell like it at times when I get out of the truck).

My truck is at my mechanic and he has gone over it from front to rear; he set the timing, but when he set the timing correctly, the truck ran worse!

The truck has had a tune-up recently (plugs, wires, cap, rotor button, fuel fileter, PCV Valve, and air cleaner). Mechanic said that when he disconnected a "round switch on the motor block that controls the vacuum", it ran a little bit better, but the check engine light came on.

Any advice is helpful; my mechanic is very honest, but neither of us want to start replacing things without knowing what direction to head in. Thank you for any assistance!

PS: Don't know if this is helpful, but gauge for rear fuel tank began working intermittently when all these problems started (it had not worked for four years). Also, fuel goes from one tank to the other (Ford dealer alledgely fixed with a recall, but I am doubtful).

sounds like your fuel pump may be going have it checked. and the gas being pumped into the other has a recall out i dont know if yours has a dual fuel tank selector valve which is a black cylinder located under the driver side door has 4 hoses coming to it and 2 leaving it. i just bypasted the front one since i never used it.

The truck has a good idle, but anywhere from 45mph up you have to the rpms above 1800 or it shakes violently . Its not wires or plugs and the motor mounts are fine. Also it will die when turning the wheel while in reverse.

scan for codes and check fuel pressure to make sure it is not a engine issue then have tires checked for balance as well as driveshaft ujoints.

No codes pull up, and its not the tires because it quits shaking when i let of the gas, also the ujoints are good

just you let up on the gas doesn't mean the ujoints are any good if they have rust around the seals then they are shot or on their way. does it have a vacuum leak? what is the fuel pressure measured by a gauge like I suggested in last reply. not by it sprays cause you hit the Schrader valve. were the wires and plugs replaced and are they in the correct firing order? does it run rough while in park or neutral from idle up to say 3000 rpm? is the front end in great shape and has been check professionally

Driving in a parking lot and truck started high idle had to put it in neutral and hit the gas to idle down. it did this three times then it wanted to flood and die shut it off. restarted it twenty minutes later it ran fine for a week then went to go shopping and got three miles and stopped at a stop sign and went to go again and it died did not want to restart. it flooded waited about ten minutes started and had to keep feathering gas to get it home changed the fuel filter cap, rotor , plugs, wires .now it only starts and idles rough and dies then does not want to start again wait about ten minutes and it does it all over again as soon as I shift it dies and smells flooded.

try cleaning throttle plate on both sides and IAC hole with choke cleaner, check for vacuum leak like a hose off broken etc. finally check fuel pressure with a gauge. see link
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

ihave a 93 f150 with a 5.8 in it and i have a problem with it when you get it on a load it runs lean and starts run bad temp starts rising i replaced comp,map,injectors,fuel reg,one way vavles on the tanks,fuel filter,tps,plugs,wires,coil,had ingtion module check,i ran it with the scanner on it and when it does it my timing retards its self down to 12 degrees and im running out of options anybody know anything else to try

Have you checked for vacuum leaks? Also, have you checked the knock sensor? (you do mean 12° BTDC, correct?)

i tried unpluging the knock sensor and that didnt change any thing i also checked fuel pessure and it is good

i put a vacuum gauge on and the vacuum is good

Have you checked the crank sensor?

its a 93 it dont have a crank sensor does it it has a pickup sensor in the distibritor is that what your talking about?

I replaced the plugs, wires, rotor, and cap and now it runs rough. It starts ok and seems to idle ok but when I start driving it, it acts like it's missing? Could I have mixed up the plug wires or is there something I'm missing?
Thank You

What size V8 is it so I can get you the firing order. Also, make sure you didn't bump off vacuum hoses.

Let me know.

Thanks for the reply but i found a sparkplug wire not firmly set and all is ok

That is an easy fix. I'm glad you found the problem. Let us know if you have qustions in the future.

Joe