Ok here is the deal i have a 302 block that i stripped down to a bare block, put all new gaskets, oil pan, water pump, new roller cam, and what not. My problem is, when i had the engine on the stand with no heads or oil pan it seemed kind of hard to turn over. I assumed it was a small bit of surface rust that formed on the cylinder walls from being in the open air. I could still turn it over with a normal ratchet by hand. Ok then i started putting it back together. And it seemed to turn ok every time i checked it. Finally i put it back into the Bronco lined everything up, got everything perfect (and i'm kinda **** with the torque wrench!) i go to start it with a brand new starter and it kinda turns over good then almost stops. Then it won't turn over at all unless you keep on the starter causing the starter to get hot. I first thought it was a bad starter so i got another new one and same thing. WTF!!!! I really don't want to take the stinkin thing back out of the truck and tear it down again, what would cause it to turn over so hard sometimes and other times it cranks for as long as i want! I'm stumped on this one. I've been working on it all week and havn't made any progress!! HELP ME PLEASE!??! Suggestions?

 

What else did you do to the engine other then what you mentioned.?

 

did you put the pistons in backwards?
did you check your clearances?

 

The tranny is in neutral right? Unhook the ignition, accessories and take the plugs out. Try turning it by hand. It should turn over easily. If it's not easy you'll probably have to pull the motor. If it does turn easy put the plugs in and try it. Then try it with the accessories.

 

Did you replace the main and rod bearings? If so do you reassemble everything back in it's correct order and place? (rod & main caps not mismatched and/or backwards?) Also sounds like the timing's retarded too.

 

Alittle bit more info would be appreciated. Read my former question an reply.

 

advanced timing would stop it from turning.....

 

Well ok, here we go. The only thing i did to modify it was the cam and valve springs. Since i had the slight binding problem before i even installed the heads, i kinda ruled the heads out as the problem. I didn't take the main caps off or mess with the bearings at all because i didn't want to disturb them or wreck em trying to get the crank out, plus the guy i bought the engine from tested the oil pressure before i bought it and said it was really good. The cylinder walls still have crosshatches on em with no scoring so i figured everything else would be fine. i was kinda thinking maybe the distributor is a tooth off. or something, i'm gonna pull it into the shop where i work tonight after everyone leaves and mess with it a little more.

 

Sounds like an ignition timing problem then. It's either advanced or retarded too much. If you don't want to pull the distributor again, you can walk the wires around the cap to accomplish the same thing.

 

Success!!!! Well i figured it out. This is a wierd one too. Never seen this and i worked at a ford dealership! The diaphragm in the fuel pressure regulator must have ruptured, causing a leak, then with no place to go the fuel was being pumped through the plastic vacuum line into the upper plenum and running down into the rear cylinders. I believe this is why the engine blew in the first place before i even bought the truck!! Wow i'm smarter than i thought!! actually i found out by accident! I left the vacuum lines off the upper intake and when i plugged the fuel pump fuse back in, instantly a garden hose like stream of gasoline from the vacuume lines! That solves that one!! Thanks Guys!