wont idle... hardly running... no power...

[lman]

I got my bronco maybe 9 months ago, it ran fine for the most part. I took the motor out (302) to do some work on it, and ended up replacing all the pistons, rod bearings, and oil pump. After I got it back in and got it running, I took it out for like 1 1/2 mile drive. Seemed fine for about a mile, then started running really rough and kept losing more power as I was trying to get it home. Had to shut it off as soon as I got back. When I tried to start it again it wouldnt idle, was running really rough, and had absolutely no power. For no real reason it started idling again, so i checked to see if it was running on all cylinders, when i was pulled spark plug wires from the distributor only four of the eight actually made a difference on the way that they motor was running. So it must have been running on only 4.
Ive been working on it and doing research for a few days now and cant figure it out. some of the time it will idle, sometimes it wont. It started loosing power, and now has so little it will hardly move. and its running really rough (like not on all cylinders).
I rebuilt the carburetor about 3 months ago, replaced all spark plugs and wires, and the rotor and cap from the malory breaker-less electronic distributor, and ive adjusted the timing. it doesnt have the original coil. the only thing i can think it would be at this point is that the distributor went bad. when i rebuilt the motor i didnt take it off since was only redoing the pistons, and it leaked oil into the distributor... would that be enough to short it out?
any ideas? i just wanted to see if anyone thought it could be something other than the distributor before i spend the money to replace it.

 

[ilovemaui]

How could change the oil pump without removing the dizzy? The dizzy turns the pump. Just asking.

 

[lman]

How could change the oil pump without removing the dizzy? The dizzy turns the pump. Just asking.

when i pulled the pump off, the rod came out really easily. all went back together just fine too.

 

[Bronco717274]

Check your carb, look inside with it not running and see if you are getting two streams of gas when you mash accelerator peddle. Each side only feeds 4 cylinders if one side is stopped up it will run like you discribed. Good luck! Check which 4 are firing 2 on each side look at intake you will see if the 4 that are firing are all on one runner than the other side of the carb is stopped up. If this makes any scense too you.

 

[Viperwolf1]

Look at the oil. Does it have specs of metal flake in it? Look at the plugs. Do they look like they're all firing? While the plugs are out do a compression test. Were the temp and oil gauges reading normally?

 

[Bronco717274]

How did you replace the pistons without removing the dist. don't you have to pull the intake and heads to get them out.

 

[red hot71]

I think it's in the carb also. One of the jets could have a speck of something in it. Just having gas thats 2-3 months old will do it. The four cylinders that aren't firing do they share the common side of the manifold?

With today's gas if your not running a tank or more a month you're going to have problems with a carb.

 

[jonpblewis@yaho]

I just had a problem with my Malory Unilight dizzy. A screw on one side of the sensor came out and allowed the lose sensor to move around and that pulled the wires into the dizzy witch then got cut up by the roter. I patched up the wires but It hardly ran like it was not firing on all or missing and then died. Something had gone wrong with the sensor. I had my old dizzy with points to swap it out till I got a new electronic sensor. With the Malory Unilight You have to be sure it is powered correctly. Check that there is a resistor in/before the coil or a resistor wire from the ignition to the coil. I also disconnected the 12 volt to the coil from the starter relay. You can't let too much go to it or it will fail. $100 + for a new one so Down load the wiring diagram and installation instructions from Malory make sure you have it right.

 

[lman]

Look at the oil. Does it have specs of metal flake in it? Look at the plugs. Do they look like they're all firing? While the plugs are out do a compression test. Were the temp and oil gauges reading normally?

not all of the plugs have looked like they were firing. i did a compression test and it came up good (120-130ish). oil reading low to ok, 35-40. temp got up very high once, but since hasnt gotten above normal

 

[lman]

How did you replace the pistons without removing the dist. don't you have to pull the intake and heads to get them out.

intake would just come off from behind the dist.

 

[lman]

The four cylinders that aren't firing do they share the common side of the manifold?

no they werent... 2, 3, 5, and 8 I think were the ones not firing

 

[Bronco717274]

Thats two on each side of engine did you check the carb yet???? One side of intake feeds two cylinders on each side other side feeds the other two cylinders on each side. If a jet is stopped up in carb you will only get fuel to two cylinders on one side and two on the other side. Those not getting fuel will not fire, pull one of the plugs that aren't firing if it is soaked with fuel than you have a firing problem. If it isn't soaked in fuel you have a fuel problem.

 

[Bronco717274]

On a duel plane intake the drivers side of carb feeds fuel to the 2 3 5 8 cylinders. The passenger side of carb feeds fuel to the 1 4 6 7 cylinders. If this help's anyone, but check the plug's no fuel on them = fuel problem. Fuel on the plug's = firing problem.

 

[Bronco717274]

Let us know what you find out on engine, might help the next time this comes up on someone else's truck. Good luck hope you get it up and running soon.

 

[lman]

Ok thanks. I will give those a try when I get home later.

 

[Outlaw Bronco]

Did you test the PSI on all the cylinders. If not try that and see what you get. Sounds like it could be a lobed off camshaft. (Will give the same issues as described)

Not saying this is the problem but it never hurts to do the test's just to rule out another piece.

 

[lman]

I have tested compression and it checks out on all.
The carb is letting gas in both sides.
And I've tried a different coil and it didn't make a difference. Sounds like the distributor is messed up and needs to be replaced.

 

[Bronco717274]

Just missing on the one side of intake that feeds the 4 cylinders that are missing I can't see the dist. doing that, but could be wrong. Check for a vacumn leak too, are the plugs that are missing have any gas on them? Is the dist. cap sitting on it straight and do you have any wires crossed. If it's in the dist. it's missing on every other one 2 3 5 8 ______ 13726548 just seems odd.

 

[Bronco717274]

Keep us posted on your progress, hope you figure it out soon. Post us a little vid and maybe we can diagnose a little better.

 

[.94 OR]

Is the distributor cap in good shape? No hairline cracks in it?