I have a 93 f150 4.9 I replaced starter,batt,cleaned connections it cranks slow sometimes gotta jump it to start it also replaced battery terminals any help please?

 

You need to check the voltage at the battery posts while the engine is running. Should be around 13.6 - 14 VDC.
Sounds like a low battery charge.

 

I took the battery out and put in another truck it cranks fine just wont crank mine?

 

Its cranks fast and starts fine if its cold if its warm it cranks very slow??

 

What was the other truck? Still check with a multimeter. By cold do you mean a cold day or motor (I'm assuming cold motor, but thought I'd check)? Is it taking a long time to start or turning over slowly (turning slow implies a longer start duration)? Try swapping another battery in, and see if it still cranks slow. Engines should be easier to turn when warm, not cold. What's the oil like? I'll try to think of what would cause that (only thing that comes to mind is a very overzealous injector, but there are no other apparent symptoms).
-Mike

 

Ive changed the battery and yes cold motor changeed starter and batt terminals cleaned all connections ? Short somewhere maybe but wouldnt it do it cold or warm?

 

I would take a remote starter switch and hook it direct to the starter. ie one terminal of the remote starter switch on the large battery cable terminal and one terminal on the small electrical bolt. You could do the same thing by taking a screwdriver and connecting those two terminals, but this would be safer. That would bypass a lot of stuff. Just for troubleshooting of course. Do you have a manual or an automatic transmission?

 

Which "connections" did you clean? A poor ground connection at the block can manifest itself as you have described. Sometimes a battery cable will develop corrosion under the insulation. Something else to look for.

 

I would redo all of your grounds with some good quality welding cable. Bad grounds can cause slow starting and I can almost guarantee that you could use new grounds.

 

Ill try new grounds I put a new one from neg batt post to fender and also crossed the screwdriver trick still nothing

 

You need to focus on the ground from the battery to the engine block.

 

The neg cable runs to the starter?

 

The negative cable runs to the engine block, not the starter. Your truck may or may not have the extra tab that also connects to the frame.

Take a look at Post #9 in this thread: https://www.ford-trucks.com/forums/1...ml#post9965674

Bill has some great photos of where the grounds are.

 

None of my trucks have an engine ground all go to the bottom starter bolt its i6 not v8

 

You did what? The negative cable runs from the battery to the starter bolt. The positive cable runs from the battery to the relay to the starter.

Also, when you say you put a new ground on, what exactly did you replace? Just the end of the cable? I have had terrible luck with just the ends. Replace the whole cable with a one-piece molded cable. They work much better.

I really think that your battery cables are shot. It's a common problem on older vehicles. The cable insulation dries out, cracks and deteriorates. This lets water in which corrodes the cables are reduces their current-carrying capacity.

You've replaced everything else. Spend $20 and put new cables on it - the thickest ones you can find - and I bet your problem goes away.

One other thing - what's your base timing set to?