[voodoomyk]

Hi I'm new here so please don't flame the Noob too much

I have a 94 F150 (2wd, 5.0) and it has me in a bit of a pickle.

Was driving through town a few months ago and it acted like it was running our of gas. Pulled it over and replaced the fuel filter. That didn't work, so I towed it home and pulled the fuel pump. New pump installed. It would start up fine, but ran really rough.

Found a small leak in my timing chain cover gasket so I pulled it and replaced it (as well as putting a new timing chain set in while it was down). Also found my dual core radiator was leaking at the filler neck so I put the old stock radiator back in. I also did a quick tune up with new plugs and an oil change. When I pulled the plugs I found that the number 4 plug (last on the back passenger side of engine) was slightly fouled with oil. After changing the plugs and oil it ran much better. But still had a problem. It will idle beautifully, drive well, but randomly I will lose all acceleration, literally floor board the gas with no results. It doesn't die though. After a second it catches and I'm back off to the races. It also heats up a little more than usual,but then again the radiator I put back in is smaller.

But it does it pretty frequently, every half mile to a mile. Obviously I havent driven it out of the neighborhood for that reason.

Some issues to note... The rear tank ended up getting a hole in it so we dropped it and plugged up the lines. Noticed a slight drip at idle when I changed the filter out on the side of the road.

Also the valve cover gasket is leaking some oil (in the same spot my plug got fouled).

Any words of advice would be great. I am not a mechanic by any means. I have a pretty good grasp on how to replace things and what not, but diagnosis is not something I have experience in. A mechanic buddy of my grandfather says it sounds like the engine needs replaced. But I hope its just something I missed.

Thanks!

 

[Mr Mac]

Right off the bat I'm thinking mass air flow sensor.

 

[voodoomyk]

Thanks Mr Mac. I will see what I can find about checking them. Or is it something you just have to buy and replace to check?

 

[Mr Mac]

The best way to check if that is the problem is with an OBD (on-board diagnostic) reader. Take your truck to the nearest Advance Auto, Auto Zone, etc., and they should be able to get any codes that might be present.

 

[voodoomyk]

Hey MrMac (and anyone else helpful

Ok...so I realized I hadn't changed the rotor button. I changed it out and the truck stopped losing total power when hard accelerating. However...the problem still persisted with the truck having lots of trouble when under load.

I would have to floor board it to get it moving, and it would send the RPMs up to about 3500 (sometimes closer to 4000) before it would shift. I got tired of scouring the internet and followed your advice. I picked up a code reader from Advance.

Initially I got codes that the MAF sensor voltage was too high, and one that said it was too low. In the same string of codes I got a code that there was insufficient airflow to my EGR and that the HEGO on bank one was having issues.

So I started playing "replace that part". I put in a new MAF sensor, and cleaned out my EGR (was very gummed up on the engine side). After I did these two repairs my performance improved, but not enough to matter. Still have to floorboard it to get onto the interstate and not get run over, even then it's pushing it. Oh and did I mention it takes a 1/4 tank of gas to go 30 miles??

So I ran codes again and this time all the above codes were gone...now I have

Code 121 (it read this code twice)
Code 133
Code 233

And after the last code I got a random "2".

121 came up as an issue with the TPS. My book said the voltage was of -or- the airflow didn't match up with the MAF sensor. I just replaced the TPS last summer, but everyone I talked to said they tend to go out frequently when you start replacing them...so I spend $40 bucks and got one. It improved performance a LOT for about 30 minutes. Now it has gotten bad again. Not as bad as before. I can tell my acceleration has improved overall, but its still revving up to 3500+ before shifting above 35mph.

The engine is also running a lot warmer than usual. Full of oil and coolant.

I'm a young guy with a modest paycheck. I can't afford a new vehicle, nor can I afford to keep playing "replace that part" Any help would be awesome! thanks.

 

[Mr Mac]

Does that scanner read DTC/OBD-I codes as well as OBD-II? If not, then the codes you got might be wrong. I only ask because I cannot find 133 and 233 codes for that year truck.

Have you taken the time to look over your vacuum hoses carefully? A vacuum leak could also cause some of these issues.

 

[voodoomyk]

It's an Actron OBDI code reader. Here is the link to the specs.

http://www.autozone.com/autozone/ac...d-1984-1995/_/N-25iq?itemIdentifier=2396_0_0_

I have "looked" at the vacuum lines, but I haven't really been over them too well. How does one check vacuum lines properly? There is a set of red and black lines together that have been capped off. They went to a can on the passenger fenderwell. A mechanic buddy removed it and told me it "wasn't needed" unless I was running a/c which I'm not.

thanks,
Myk

 

[Mr Mac]

Any vacuum line that seems brittle or has cracks all over its surface is suspect. For the plastic lines look for places where they have been bent/kinked. Vacuum lines are cheaper than sensors for sure but that doesn't mean it still isn't one of them.

While you're looking over the vacuum lines, what about the air filter and induction system? Have they been checked and/or replaced as needed?

 

[voodoomyk]

Thanks for the info. I will give them a better look.

New symptom, could be random, or it could be related. I nicked my top radiator hose today, made it to the side of the road before I lost all my coolant. installed a new hose, drove home after topping the coolant off. Had VERY terrible acceleration. I had to floorboard it to get it to 40 mph and that took about a 1/4 mile. limped it home and popped the hood. Headers were cherry head on the back two sections on both sides and the coolant was very very hot. Engine never got out of normal range on my temp gauge though. Was on the high side of normal.

It starts up and idles perfectly fine. I haven't tried driving. I unplugged the battery about an hour ago. Hoping to clear the codes and then scan again to see what pops up.

 

[Mr Mac]

Now it's sounding like your catalytic converters are finished.

 

[voodoomyk]

could that cause all the other stuff? I had a clogged cat on a toyota van years ago and it acted similar. Everyone I have mentioned this too leading up to this has said I was crazy. I live in a town where we don't have to go through emissions...I think my hacksaw and I have a date...

 

[voodoomyk]

Update.

I cut a good sized chunk out of the exhaust between the 1st cat and the o2 sensor. I also snagged the vacuum can the mechanic took off and hooked it back up. I now have acceleration again and the headers aren't getting cherry red. I did 2 loops around my neighborhood giving it some juice (my normal test drive route) and it didn't get red hot.

However its still throwing a p0122 and p0123 code. Before I hooked up the vacuum can it gave me a p0121. All of them are TPS related. I replaced it about a week ago. Think the other issues could have burned it out that quick?

 

[loosearrow45]

I had the same problem and dumped a bottle of lucas injector cleaner and it fixed the problem i also have a problem running too rich cant figure it out