Ok let me start this off by telling you my problem.

I have a 93 F150 auto 351 with 150k, I have owned sence it was new. Sometimes at an idle and in drive it runs very rough and at other times it seems fine. Just starting it has become a little harder when it is cold. Most of the time with out a load it seems to run fine. If I am pulling a load, it is apperent i dont have the power i used to. I tis sluggish on take off and climbing up to speed. I can not get it above 60mph. At 55 it dont seem to have a lot of power but it will maintain the speed. If I speed up to 60 it will soon start missing or acting like it is starving for fuel.

Here is a list of things we have tried in the order we tried them.
Changed fuel filter
New rotor, dist cap and plugs.
Checked TPS w/ omh meter
Checked fuel pressure while on either tank. (32psi @ idle, 34 at 1/2 throdle)
Added one can of sea foam to the gas
New plug wires (Improved some)
Had the ECM checked at Oriels and it checked out)
New coil
New O2 sensor (Mechanic told me the computer codes indicated a bad sensor)

The mechanic felt like he fixed the problem but this Morning I started it (still a little stuborn staring) and put it in drive and it started running rough.

Any ideals?

 

clogged cat convertor?

clogged air filter?

after g.w.bush was elected, i lost my ideals.

 

Just following along, having a very similar problem, but I've already run with no exhaust, much to my neighbor's dismay, changed air filters, and am halfway through a compression test which shows all cylinders to be between 130-135psi.

This might cause me to start drinking again.

 

I hear ya Stanman. Its driving me that direction also. Several times i thought i had it fixed just to find out a few days later its back to the drawing board

 

Hell Im on my second beer.

 

Mcfad....your behind...finished with a 6 pack and changing over to burbon on the rocks...hicup...

 

sounds like were getting much closer to actually fixing the problem...

 

And the problem gets worst. Yesterday (after keeping the bolts sprayed with blaster for 2 days) I removed the right side exhuast manifold to fix a small leak on the 4 port thinking this leak might be contributing to the problems. Well, the bolts where so rotten that 4 of em twisted off. 3 of the 4 have around 1/2 in exposed and the other one is flush in the head. I was thinking of running a nut onto the exposed stud and welding them then trying to back them out. Any one ever try this?

 

Ok... Exhaust manifold studs....:

1. sounds like you can weld, so on the ones that you have an exposed portion, weld a nut onto them and try turning them off with a breaker bar. Doesn't hurt to add some more penetrating oil after the weld cools down a bit.
2. If the stud is broken off flush to the surface of the head and you think you can MIG a piece of stock (maybe a bolt, or something) onto the stud at say a 30 degree angle, try that and then try rotating it out with a box-end wrench. This is where one of those welding helmets that shades its self when you strike an arc really comes in handy, because welding the broken stud to the head would suck.
3. You can also try heat with a torch. I try to stay away from this option...
4. Reverse drills and a tap are your last option. This takes a lot of time and can be frustrating... If you end up doing that, do a little research on broken exhaust manifold studs, it hapens all the time. Basically you want to be perfectly centered when you start drilling/tapping, as to not destroy the threads.

 

Thanks gweeds. So far i have gotten 2 of them out by welding a nut on to the stud. Now i have one exposed stud and one broke off a little deeper than flush. The exposed stud I have welded 3 nuts to it now and the top of the stud just shears off. I dont trust my welding enought to try welding a rod to the other one...guess i will be drilling for a while.

 

Hey Edd that sounds prett good Im going to jack n coke

 

I got num 3 out. Only one left is the one that will have to be drilled. Any suggestions on a good quality bit that will drill this stuff. The ones i have are not going to drill that bolt.

 

Its a good idea to invest in more expensive bits in just the sizes that you need than buy a whole set of cheaper bits, when it comes to those types...

You can try using reverse drill bits first if you want. What you do is drill a hole the size of the middle of the reverse bit (they are tapered) and turn the bit backwards, which grabs onto the metal and hopefully backs it out. This isn't guaranteed to work, but its guaranteed not to mash up your threads if you don't drill a perfectly straight hole (to a reasonable degree, of course...)

 

What is the better bit, Carbide, tungston, titanium?

 

It has been suggested to me that the ECM could be intermitant. I have had it checked but the tester shows it to be fine. Any one ever heard of this?

How can I find out if I have a bad injector?