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cdiedrick 04-26-2008 04:30 PM

Misfire
 
I did some work on my engine put in a new oil pump last fall, then winter hit so I didn't drive the car. I was not happy with how it ran but I figured I would get back to it in the spring. It is a 79 T-Bird with a 351M it started hard, backfired and then I got it running. Under a load it misses big time at about 3000 RPM but runs fine otherwise. According to my timing light my timing is advannced 34 degrees. That is a bit much but it is the only way the car runs smooth. What is going on? IS my distributor off a gear perhaps? Did something go bad with my distributor. Any ideas will help.
Thanks
CHris Diedrick

carsavvycook 04-26-2008 06:17 PM

Is your idle searching?

cdiedrick 04-27-2008 11:04 AM

Not sure what you mean by that. It seems to idle fine, its just higher rpms under a load is when the misfire happens.

carsavvycook 04-27-2008 11:25 AM

If the base timing is not set right on most Fords I've seen the idle go up and down, not stay steady.

Chevyboy454 04-27-2008 11:26 AM

Sounds like timing for sure, pull off the dis cap and grab a socket and bar, roll the engine until the rotor starts to move then roll it back if you get a delayed movement in you rotor as you turn the crank bolt suspect a bad chain. Did you take the Dis out at any time? Possible you droped her in a tooth off?

cdiedrick 04-27-2008 01:16 PM

I did pull the distributor, and I suspected that it might be off a tooth. just wondering which way I should try to move it then

Chevyboy454 04-27-2008 08:55 PM

I am a die hard Chevy guy, not too keen on the ford side of things however, If the drivers side valvecover is easy enough, remove it. Pull #1 plug and rotate the crank until the piston is all the way up and the valves are closed. This indicates TDC (Top Dead Centre) Compression stroke. Pull the cap off the Dis and look at the position of the rotor, inside your cap it should be marked with a number one or follow the wire from 1 to the cap. The rotor needs to be pointing to number 1 in the cap so lift it out and adjust acordingly. Not sure what your timing should be set at but if you pulled the Dis you probably put a mark on the base of the dis and the block to indicate where it went, if not borrow a timing light from someone and set her up.

Now I know some fords have odd ball cylinders so you might wanna check for sure what cylinder is number 1, pretty sure its the drivers side closest to the rad, but don't quote me on that. Either way this proceedure will work once you determine number one.

If the valvecover is too hard to take off, TDC is good either you will be bang on or 180 Deg out. If 180 out just pull the dis again and rotate 180.

Cheers and hope this helps. Rick.

toecutter 04-27-2008 09:21 PM

I concur with chevyboy454

I would start there so as to be certain of proper mech timing.

techinspector1 04-27-2008 10:41 PM

Yep, Fords number differently. #1 is at the passenger side front, then number straight back on the passenger side 2,3 and 4. #5 is at the driver's side front, then number straight back on the driver's side 6,7 and 8.

Chevyboy454 04-27-2008 10:49 PM

That's what I thought but wasn't 100 percent sure. Like I said Big Chevy guy. My thoughts on the newer Ford's are "Well at least they circled the Problem for us". Don't get me wrong I like the older more reliable Fords, (when Ford was built tough) but anything I have to lift the cab off the frame to change a spark plug really iritates me! That's if they managed to stay threaded in long enough to be replaced. However it doesnt matter what you buy today they all have there flaws. I just find in the Tech side of things I see 2 Chevs in my shop to 10 Ford / Dodge / Imports. And the Chev's usually need a Alt / Batt / Brake Job / or an intake,Head gasket job. Particarly the 3.1, 3.4.

Just my 2 cents. lol

Cheers Chevyboy.

chevy350_Camd 04-28-2008 11:21 AM

If its not timeing ...
 
If your timing shows up good after you pulled the distributor and set it to the number 1 cyclinder check your spark and see if its strong and blue if not it could be the plugs after you rule out the plugs check your coil, And if its misfiring is usually a case of retarded timing and I doubt your 34 degrees before is a little bit to slow :mwink: Sounds Like a weak spark Good Luck


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