The plugs say Autolite Double Platinum on the insulators. Aeroman59, I just replaced the fuel filter and the air filter is pretty clean. I also know I have the synchronizer in the correct phase with the crankshaft, I had it 180 degrees out of phase one time and it would barely even run at all. The vibration and performance is better than it was when all this started, and it park and at certain speeds the vibration is barely noticeable, so my question is, if i didn't have the crankshaft at EXACTLY TDC, but a few degrees off, would this cause the vibration and slight loss of power? I don't even think my engine has a TDC on the pulley, atleast as far as I could see.

 

A few degrees off is not going to cause that problem, the engine also is looking at the crankshaft position too, & is what is used for accurate ignition timing etc.

An engine mount has not come loose or broken?
Do you have a worn driveshaft universal joint perhaps?
Rich mixture can make the engine feel lumpy.

Just a few ideas!

Aeroman.

 

Hi Aeroman, ok on the synchronizer. I thought it might be a motor mount cause the vibration issue showed up overnight, but the folks say it doesn't have as much power as it used to, and I know it's not u joints cause I had them replaced about 20K miles ago and you get the vibration bad if you have it in park and bring the RPMs up slightly, it has a "sweet spot" right at about 50-150 rpms above idle rpms from what I can tell where the engine shakes quite noticeably, but then kinda smooths out with slight vibration after going higher, and when you put it in drive but aren't moving the vibration becomes more noticeable too, and around 55mph you can really feel it vibrate cause it's probably hitting the spot on the RPMs. the only code I have now is a p1443, I've replaced the vacuum lines, would a bad purge canister cause this? And wouldn't running rich show a code?

 

Running rich will throw a code if it gets bad enough, but within the grey zone it just logs a LTFT. Do you know what your LTFT value is?

 

What is LTFT?

 

I'm pretty sure it means Long Term Fuel Trim.

 

Long Term Fuel Trim