Good evening everyone!!
I am trying to find a thread that may help me out. Surely my problem has been discussed somewhere.
I have a '95 F-150 with a 4.9 5-speed. I decided to give the truck a complete tune-up. An acquaintance of mine offered to replace my distributor with a new one I had bought the day before. The reason I wanted to replace the distributor is, I can't seem to find a slight miss and something about the pickup coil was said. I have replaced just about everything under the hood (tps,icm, pcm, o2 sensor, egr, starter, alternator, battery, map sensor, fuel pump, ground cable, clutch, damn near everything). I let my acquaintance handle the distributor, and he screwed it up. He did not set the pully to TDC before removing the old distributor. He swore he could put the new one in its place without disturbing any gears. He builds transmissions, so I believed him. The truck did start, but would die immediately. He started twisting the distributor until the truck would stay running. At this point, it began to rain. He bolted home, and I am stuck with this project. Pulling up the steps online, I removed the spout plug, turn the pulley to TDC of the compression stroke, turn the rotor to number one distributor cap, and drop in the distributor. The truck fired right up. I turned the truck off, replaced the spout plug, and went for a drive. The truck drove better than it ever did since I owned it. the slight miss was gone, and the truck had alot more power. But, after day two, it started sputtering. It was sputtering, jerking, and bucking, all the way home. First thing I did was look at the timing. It was off, so I figured I put the distributor in wrong. I parked the truck and did the whole project over. Removing and checking plugs, fuel, and fire. I have everything back together now. The truck will fire right up and idle excellent with the exception of a slight miss. Under accelleration, it will sputter. I have tried to advance and retard the timing. The RPM's go up or down, but the miss is still there no matter which way the distributor is turned. After letting the engine warm, I put the timing light on the pulley. Right now it will idle back and forth from 10 to 14. If I accelerate, the timing mark does not increase past 14.
OH YEAH!! I forgot, when I was setting the pulley to TDC on the compression stroke, I could not get the truck to start, and the rotor would be 180 degrees off. I set it at 10 degrees TDC and it fires right up. I hope some of this makes sense, but I am lost as to what to check next. I do not mind starting this project over for a sixth time.

 

Hate to sound like I'm picking on you, but, when you timed it right, did you tighten down the distributor clamp, so it wouldn't move on you?

 

I did. I'm actually worried about breaking it, with all of the loosening and tightening.

 

Are you using the correct sets of timing scales and marks?

 

Yes. The hardly visible scratch on the pully, and the notches with the larger notch located on the passenger side of the balancer.

 

New fuel pump was bad after all.

 

Not unexpected -- about 15% of the "stuff" out of the box can be defective.......................that's why we (on this forum) warn folks not to throw a lot of "new" parts at problems........often just compounds the problem