1995 5.8 F150, The truck has a very bad miss, worst around 1000 to 1800 RPM. The same miss occurs under load or in neautral. Fuel Pressure is perfect at rail, timming is set to spec 10 BTDC, replaced plugs, wires, cap, rotor, oxegen sensor, coil, went through a full bottle of Lucas fuel injector cleaner(A few tanks full). Not one bit of change. The truck did this when I got it so I don't know if it started slow and got worse or just happened. Pulled codes and only got RPM not raised sufficently during self test (No Kidding computer, that's the problem!) Also checked vacum and it held a steady 50 inches at Idle. No smoke from the pipe, but the bad vibration caused by the miss and lack of power. I'm lost and I guess I'll have to take it to a mechanic unless someone has a better idea. I thought about a plugged or leaking injector(s) or maybey bad ignition module or distributor. But money is to tight to continue throwing parts at it. Help!!

John

 

when you replaced the plugs, what did the old ones look like? Is there a certain cylinder that's misfiring or is it all of them? What about doing a compression test?

 

Have you verified the firing order is wired up correctly?
Did you pull the SPOUT connector when setting the timing?

 

plugs were worn, none looked any worse than the others, timming was done with spout disconected and firing order is correct. I haven't done a compression check because I don't have the tool to do it, but I thought if I had bad compression with one piston I would see some blow by smoke or get an unsteady vacum reading?

 

Get a new F-150?

 

Since you have covered all the basics, take a compression test. If that shows up good, pull each plug wire one at a time till you find the bad cylinder, then pull the valve cover and see if you might have a worn cam lobe.

Good luck and let us know what you find.

Drive safe,

Dan Harriman
Orange, Texas

 

...not even gonna acknowledge the 'new f150' post.

Have you pulled codes to get some clues? Could be EGR, MAP, TPS, etc. causing those symptoms. Instead of throwing parts at it, run it by the local auto parts store and have 'em pull the codes so you have an idea where to start.

 

I would like the new F150 KingRanch to back up to my 1996 5.8s reese hitch and tie on and see WHATS UPPPP!!!! I like the new trucks but I Love the older F150 boxbodys and you cant beat a 351 in power,sound,reliability.

Oyeah whats up with the Tighta#$ advertisement on your deal????
Dude thats embarrasing from where I come from!!!(AMERICA)

 

I also think that you have a badly plugged injector. Do like what was said above and pull the plug wires one at a time to see which cylinder is misfiring. When you find it then check if the plug is firing. If it is then swap an injector from another place (if you don't want to buy one before making sure that's what it is) and see if the misfire transfers to the place you swapped it to. You won't get a code for a plugged injector and you sometimes won't for a bad ignition module or TFI. At least the ignition module can be tested at the parts store.

 

Thanks everyone, I'm going to give it one more shot this week when I get some time off. As for the new F150, if you want to give me one for free I would not argue