Hey guys, so my buddy borrowed my 1980 bronco xlt 351 auto for the weekend and when I picked it up it looked like he'd been driving it pretty hard (lesson learned). Anyways, I started it up (it took a min) and it sounded really off. It doesn't idle smooth at all and the engine jerks a bit. I tried to drive it home (10 mins) and it died 4 times, and had a lot of trouble getting up to speed. I ended up leaving it on the side of the road because it won't make it up the hill to my house. My first thoughts are maybe a severe misfire or a timing issue but I'm still pretty green so any advice would be great, thanks

 

I advise you not to let your "buddy" borrow your truck anymore. Might even need to beat his ***. Really hard to tell from your description what it might be. Time to do some under hood detective work. Could be blown up.

 

Ya I shoulda known better. Now that Im thinking more about it, it felt like it was out of gas the whole time (Its not), maybe the fuel pump is bad? I just got the truck and the only thing I've done is the fuel filter. I'll look more into it today, just hoping you guys can give me a few things to check for?

 

Any thoughts guys?

 

Check the plug wires to make sure they're not rubbing up on each other. Sounds a little familiar to a thread about this not too long ago.

 

Not rubbing together? Ok, any chance you remember the name of that thread?

 

sorry to hear about the car trouble that sucks.

Hard to say if something went wrong while it was out of your hands but sounds like it is new to you anyway. how much time do you have driving it?

if this was never happening before and you know that forsure and have time driving it to say so then your carburetor most likely came out of tune from your friend mashing the gas.

First check all your spark plugs for gap consistency and color consistency. make sure you have a light brown color. black or worn plugs need to be replaced and are a sign you are running to rich.

Most likely issue is from the 351m engines with the over half inch space between the piston and spark plug makes for a lot of pre detination which are the sypmtoms you describe. alot of that is due to the poor cleveland open combustion chamber mixed with a low piston to deck height and the retarted timing ford made to help reduce emissions and kill performace of the engine.

then add 35 years of carbon on your heads and in your intake and exhaust runners soaking all the good fuel from flowing in and your experiencing detonation city so do not run it like this till you do some diagnostics.


sounds like you need to have your heads rebuilt or minimum pull them off and grind out the chambers or glass bead them with a sand blaster. maybe step up to a hotter spark plug.

Try some "sea foam" or similar product sprayed into the carburetor if it runs long enough to do that and may help burn some of the carbon out and help.

Check the spark plugs first and let us know as well as make sure all the carburetor linkages and vacuum lines are intact.

 

Ya I've only driven it about 7 or 8 times. I was planning to do a tune up anyways, so I'll pull all the plugs and check them out and put new ones in regardless. I'll do the wires as well. And I'll try the sea foam out, thanks for the tips, I'll get all that done early next week and report back

 

test the ignition coil too. look up factory resistance specs and test with an OHM meter. there are ways to test them on you tube for spark as well to see if its strong. have the alternator tested also.

definatly re calibrate the carburetor

 

I looked, went back a dozen pages or so and then looked for my posts and went back another dozen and couldn't find it

 

what do you guys think of these?





or these?