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So, brought my 1995 F-150 5.0L to guy who gave it a tuneup, new spark plugs, distributor, wires. Well now it's running a little rough and engine is pinging when say I am going up a hill. If I floor it, it will stop pinging and knocking, but I shouldn't have to do this. The last thing he mentioned to me before I picked up the truck after tuneup was re-doing the timing, so maybe he forgot to do timing? But am confused as I thought there was no way to adjust timing on this engine, if timing is bad all you can do is replace ignition module? Unless my reading up about this is wrong.
The base timing IS adjustable, (the factory calls for 10°, but most find around 12° gives a little more power and economy) but all of the advance work is done by the computer.. He may have adjusted the timing without pulling the spout connector, if he did the timing is probably around 12-15° too far advanced.
Yeah back the base timing off. I tried 13* advanced base timing and she didn't like it. 11* works but more than that and it pings. That mechanic shoulda test drove it. If you paid him for the work, bring it back in and ask him to back the timing off a little, explaining that its pinging under load. Just don't ignore it! 10* with SPOUT connector unplugged is factory base timing.
EDIT: the timing adjustment is simply loosening the distributor hold down bolt and turning the distributor. IIRC clockwise retards timing and counterclockwise advances, but I could have that perfectly backwards.
.. He may have adjusted the timing without pulling the spout connector, if he did the timing is probably around 12-15° too far advanced.
Hooking up the SPOUT allows the computer to advance the timing. Setting it that way would require you to back all of the computers advance out of the base timing which would result in retarded timing, not advanced. If that happened it would run poorly and suck gas, but it definitely would not knock. Still likely that timing was set too far advanced, just not in that way
EDIT: the timing adjustment is simply loosening the distributor hold down bolt and turning the distributor. IIRC clockwise retards timing and counterclockwise advances, but I could have that perfectly backwards.
I'm pretty sure that CW advances the timing and CCW retards it. But I've been wrong about things I've been pretty sure about before too. Bottom line: check the riming before you move the distributor, move it a little and check it again. You'll see if you went the right way or not.
Nope, it turns CW. This is where I always get yself al twisted around and by the time I'm done I'm doubting myself. So I'll see if I can explain it without getting all of us confused.
Advanced timing means the plug fires earlier. So to advance the timing you want to turn the rotor backward (CCW), so it's farther in front of the post on the cap. But you don't turn the rotor to adjust the timing, you turn the cap (and the rest of the distributor). So you turn it the opposite direction or CW to advance the timing.
Well, brought it back and he rechecked and it's at 10 degrees. So, it looks like maybe I should ask him to bump it to 11 degrees? Of course this is all assuming that's the issue.