I've got an 85 e-350 with a 300 straight six in it and its been giving me some issues. I bought it a couple weeks ago, its my first ford. It was misfiring occasionally when I bought it. Since then I have replaced the plugs and wires, distributor rotor and cap, ignition coil and ignition module. I have not checked the timing on it yet and the idle is a bit rough. The misfiring is particularly bad when I shift into forth gear, so bad that I cannot accelerate up the slightest incline. Thanks for any insight/pointers in advance.
Andre

 

You need to check the timing and the vacuum advance on the distribiutor

 

I checked the timing and it is fine. How do I test the vacuum advance? Thanks

 

What vacuum advance? A 1985 is a TFI distributor which should be all computer controlled with a feedback carb.

If it was me I would verify that the outer ring on the balancer hasn't spun. The outer rings have been known to slip/spin on the balancer. When this happens your timing marks are no longer accurate.

Once you are sure TDC is actually TDC then pull the spout connector and check the timing.


You might want to look into swapping out the TFI distributor and swap in the older DSII set up. And consider swapping out the carb for an older non computer controlled one.



A compression test and checking for vacuum leaks might not be a bad idea either.

 

i would guess that your electronic feedback system is incomplete or otherwise FUBAR'd, in which case swapping to a duraspark distributor and conventional carb would be your best bet.
if the system isn't compete, timing is locked into base timing, and its gonna suck

 

I have read what you are saying before but it doesn't make sense to me. There is a vacuum advance on the distributor and it is a DSII ignition set-up.
I don't have an o2 sensor in the exhaust or exhaust manifold and the only electrical connection to the carb is the electric choke. Everything else is vacuum lines. What other things can I look for to determine what it actually is?
I know that the engine isn't original. There is an ID sticker on the front of it right above the thermostat which according to my Chilton should tell me the model year, and the year and month when the engine was built. Of course it doesn't tell me how to decipher the sticker... I have done some fairly extensive internet searching to figure it out and cannot find anything conclusive.
How would I go about checking to see if the rings have spun/shifted?
Thanks again for enlarging my understanding of this!

 

ok, so you just told us that the previous owner already made the conversion we were telling you to do.

now that thats out of the way, we can start with some more troubleshooting. to start with, check the timing at idle with the vacuum line disconnected and plugged. before getting out your timing light, start by removing the #1 spark plug and turning the engine over by hand until the piston is at top dead center (TDC). its helpful to stick something like a zip-tie through the spark plug hole and use it to feel the piston's movement. once you find TDC, look for a mark on the harmonic balancer around one of the two sets of timing marks. note that there are two sets of timing marks, one on the timing cover, and the other on a little tab that bolts onto the engine's right side (your left looking from under the hood). some harmonic balancers have a mark for only one of those two areas, so you need to check them both. at this point, it'll be obvious if the marks are accurate or not, as they either line up real close to the 0 mark, or they're somewhere else. if the marks are wrong, take a file and put a little groove on the balancer right at the 0 mark, then put some white paint on that exact spot, so you can see it easily. its also advised to put paint on the factory marks if they're still accurate. once that paint dries, you can now get good results from your timing light, which i trust you know how to use.

once thats figured out, you may also want to take a look at your carb. to start with, verify that the choke opens fully in a reasonable amount of time.
i'm sure you can find 1000 pages of reading material on tuning a carb, so i'll let you do a search on that side of things.

 

Sorry but since I have a Diesel Van and my 77 460 has a Holley 850 as listed in my sig..I did not know that ...Just trying to help ....As to add onto what Josh said .....Chalk also works well to mark the timing on the balancer ......Also I would throw that Carb in the lake / garbage and get a Holley or Edelbrock...much better quailty and Infinitely tunalble .....not like Motorcraft POS....

 

The problem with a Holley or an Edelbrock carb is they don't fit the stock 1V intake very well.

There is nothing wrong with Motorcraft carbs. And I don't believe the stock carb is a Motorcraft anyways. I'm pretty sure the Feedback carb was a carter. If he had the feedback carb the simplest solution would be to swap on an older non-feedback Carter YF off a 82 or older 300. The 4V carb requires an expensive intake swap which isn't needed unless you trying to increase the power output.





AndreVR If someone swapped in an older engine, like it sounds like they did, do what joshofalltrades described above. But I would also suggest picking up a vacuum gauge if you don't have one. They are a great asset when diagnosing problems and tuning. Hook it up and run the engine and see what kind of vacuum you've got. The type of reading you get could help determine some issues. These engines are also known for developing vacuum leaks where the intake meets the head.