Truck ran before this was all changed but just missed alot. Started truck after this was done and it runs worse. found out firing order was off, so i fixed that i also put the conductive grease this time, ran better, but still not right. i put old coil back on to see if it was the coil, still the same. took all plugs back out there seems to be alot of carbon this time, cleaned the carbon off the points, the old plugs did not have all the carbon build up on them. Could I have done something by running it with the firing order off.
In a bind!!!
thanks

 

New engine at 127,000 miles. Seems to be running better the more I run it.

 

If you know anyone with Auto Tap Diagnostic software, now would be the time to call in a favor. Seriously, though, O2 sensor could be bad or going bad -- just to coincide with your maintenance. I'm no 4.2 guru. You may want to try posting your problem of the V6 section.

 

Well I took it for a long drive and it seems to run fine. I do think it could run better though.. Just dont have the power it used to. I know its got alot of miles, the dealership never could find out why it would misfire, so i drove it another 30,000 miles and heard the coil may fix it, so i tried it. Its done alot of traveling and hopefully do alot more.

 

JohnWylie,

You really don't have too many miles on the engine itself if it was replaced at 127,000. I do have to assume that everything else is original though and has more like 187,000 miles. That is a lot of miles on the fuel injectors and engine sensors.

You could be getting a misfire from a clogged fuel injector. A dirty MAF sensor (Mass Air Flow) could also mess up the air/fuel ratio. If you still have the original oxygen sensors, they are surely not functioning properly, but would most likely throw a code.

If you get a digital multi-meter, this is a very useful tool for testing the sensors to ensure they are within their specifications and limits. The HO2 sensors are very simple to test. The Haynes and Chliton's manuals offer a procedure. Stick a couple of pins into the wires holes on the HO2 sensors and connect the probes to the pins. Start the engine and see how they behave.

You may also consider changing the fuel filter and using a fuel system cleaner. This sounds like an engine misfire, so if the coils, wires and plugs are good, it's most likely a fuel flow issue.

 

Its no longer missing, the HP is not that great, it has had some o2 sensors changed, the dealership went round and round trying to fix the miss. Im hoping the coil will fix it. the reason it was running bad is because the plugs had carbon all over them, that seems to have cleared since I found out the right firing order.
It takes a few hundred miles after the plugs have been changed to see if its going to miss again. If it doent miss then i know the coil fixed it. the porcelain on the plugs would have a hairline crack. so the dealership would change them again. i will be changing the fuel filter today and that may also help some to. thanks for all your help. anymore ideas let me know.

 

Did you disconnect the battery and drain the reserve power from the computer after changing the coil and the plugs? I have heard that if you don't do this it could take some driving for the computer to figure out the new parts and adjust for them.

 

Yes i did that several times, as soon as it would start it ran fine within a minute or so it would go downhill and start idling rough, so i never would drive it cause i new something was wrong. but everything was put in correctly and it just ran fine after a while, when i put it back on the road. i changed the fuel filter and put gas tratment in it today. is there a certain brand anyone recommends on the gas treatment?

 

Get some ammonia-based window cleaner and set it on a fine mist spray setting. At night when it's dark, disconnect the underhood light bulb. Then start it up when it's warm and possibly misfiring. Lightly spray all the ignition wires starting at the coils and working your way to each plug. You should be able to hear and see something if you have a bad wire. If not your wires are ok. Get a service manual and check the resistance of your coil packs.

I had a misfire after I replaced my OE plugs with Autolite Platinum Pro's, swapped them for Champion Truck plugs (copper) and it runs great. Sometimes you can have a bad plug... it only takes one to ruin your day.

Check for vacuum leaks.

Although I haven't tried it, look into the Sea Foam treatment to de-carbon your motor, that might help the power situation.

Good luck.

 

I had a problem after I did wires and coil packs. To get at the coil pack on the drivers side I removed the MAF harness (I have the AF1 on there) and forgot to replace it before driving the truck. It ran a hell of a lot better with the MAF plugged in.

This is probably not the problem you have but it's worth making sure the wiring harnesses are all tightly in place.