1988 F150 Running Rich and bad!
 

Ok guys, try to figure this one out - I am at wits end and need some good help to figure this one out. Bare with me while I explain all I have done. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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It's a 1988 Ford F150, 5.0 engine fuel injected (20,000 miles on reman), 4 wheel drive with air. <o:p></o:p>
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Here's everything I have replaced or done so far:<o:p></o:p>
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Plugs, wires, cap and rotor, air filter, pcv valve, fuel filter, right exhaust manifold, sending / low pressure pump unit in front tank, coolant temp sensor, egr valve, map sensor, new distributor with pickup coil and ignition module, new intake and plenum gaskets, fuel injectors.<o:p></o:p>
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I cleaned the throttle body and the IAC. I checked the wiring harness connector to be sure there wasn't any rust or corrosion - it was clean and tight. I ran the truck on both the front and back tanks and it runs the same off both tanks. <o:p></o:p>
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The truck is running real rich (like 8 mpg). The exhaust stinks badly, (unburned fuel?). It is bucking really bad. The motor is not shutting off it is like it is loosing power (electrical) bucking and kicking. It runs worse at low idle and low speeds. It seems like when you get on the gas it isn't as bad except that it is lacking power real bad. I have had a few of my friends look at it and we all seem to think it is something electrical. At this point I am not sure what to do. I had the fuel pressure checked and it is ok. The check engine light comes on after like 12 to 15 miles. It is giving a lean code. Although I know it is running rich. I am about to take it to a Ford dealer and just let them figure it out - It would be nice to fix it on my own though. Any help would be appreciated. <o:p></o:p>
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Thanks, Todd<o:p></o:p>

fouled plugs.

are they platinums?

did you replace all that stuff at once?

give a bit of a time line and less smilies.

did you change the plugs and then later change the air filter?

I'd grab a timing light and see if the timing is off on the truck.

I forgot to mention the 02 sensor was replaced also.

I am not sure the brand of plugs that I put in.

1. The plugs and wires, cap and rotor, air filter, exhaust manifold, 02 sensor, pcv and the sending / low pressure pump was all done at the same time.

2. Still having trouble I replaced the coolant temp sensor.

3. Still having trouble I replaced the egr valve.

4. Then the map sensor.

5. Believing I may have had a vacume leak I replaced the intake and pletum gaskets along with the fuel injectors.

6. Still having trouble I replaced the distributor with a new pop up coil and ignition module.

We set the timing after the new distributor was installed.

All this in the past 4 or 5 months. I don't drive the truck that much. Weekends for racing.

And, I have no idea how that smiley face got into my post. If anything it would have been a sad face at this point.

It seems like the fuel / air mixture is not right. Whatever controls the fuel / air mixture? It is like it is running on all fuel and not enough air.

Have you replaced the exhaust system?

I would say that the muffler and pipe from the converter back is about 2 years old. The converter is approximatly 3 or 4 years old.

That should be good then.
When you had the fuel pressure checked what was the pressure?

It was in the low 30s. I don't remember exactly the number but it was within tolerance. It was checked at a garage.

One cause of running rich is the fuel pressure too high.
I would think the next thing to do is carry out a leak down test to see if you have leaking fuel injectors, however I`m not an expert but I think that is what I would do.

Fuel injectors were all replaced a few weeks ago when the new intake gaskets were installed.

I recently experienced these symptoms on my I6 and it turned out to be a bad plug wire and/or crossed plug wires(correct firing order, but poorly routed aftermarket wires that were too long and crossing) Check that first, before spending anymore time and money on other parts that have no business going bad. After that, follow up on that lean code, as I doubt it is giving that for no reason.<o></o>

Ah yes! We did re-route the plug wires to make sure they were not to close or crossed to assure that they were not cross bleeding. The wires were just put on about 2 months ago so I doubt that there is any bad ones. That doesn't mean that there is not a bad one in the group. But, this problem is the whole motor - if it was just a miss it would have probually been fixed already. The whole motor is cutting out and in. It is not shutting off but it is cutting in and out like it would be something electrical. A module or sensor...........How about the coil? Could this cause this type of problem?

I am about to take it to a Ford dealer and just let them figure it out

Good luck with that! Never once had a dealer find and fix a problem for me, always got one back with the statement "we can't find anything wrong" or several other various excuses to go with the bill for doing nothing. Only to have to bring one back home and find the problem myself after the time/days wasted with them. Say I'd be basically at a point fast where I'd be stumped by one. No rhyme or reason for the problem but there it is. My trucks work for me, the whole idea was to save time so I'd figure in and out with them and its back to work. Yea right, nope not with no dealer I ever been at.

How about the FPR on this thing, anyone check it out? I see nothing about it in your list but it is a little hard to follow with the HTML coding thing that happen to ya.

How about the O2 sensor, was a quality one put in or a auto super mart cheapy? As well as all the other ignition parts? Good stuff?

Yea all good parts. What is the FPR? Fuel Pressure Regulator? If so how do you check it?