Just dumped $3000 into rebuilding the motor and trans (see sig). Dropped the SOB back in, got everything hooked back up and I get this: Turn the key foreward, get all the indicator lights to cycle, headlights are very bright and fuel pump cycles to prime the injector rail. Turn key to start and I get VERY slow cranking and everything dims out so bad you can barely see the indicator lights in the dash and the headlights almost turn off. I also tried without the headlights but wanted to see how bad the draw was. So I assume battery is dead. Try 3 different batteries, a jump-pack and jumping it to another truck while running, no good. Took the starter in and had them bench test it, starter tests perfect, wire wheeled the started and trans mounting location to ensure good ground for the starter, still no good. Bought a new starter relay for the fire wall, still no prob there. Try jumping the terminals with a screwdriver on the starter relay and it does the same. I then thought it may be bad/insufficient grounding. Check and retighten/clean all ground locations and add one straight off the negative terminal of the battery straight to the block with 4ga wire, still no good.Profanity Removed Iam gonna go buy my buddies Chevy and leave this thing on the railroad tracks....

 

sounds like something was mistorqued.

 

I would have to agree. sounds like something is too tight .

 

Does it crank with the plugs out?Some new motors are really tight. You may have the wrong rod or main bearing sizes. I did that and my motor wouldn't crank.

 

My money's on the firing order.

After one of the many times I had my motor apart I experienced the same exact thing. The battery WAS on it's last legs so I went ahead and got a red top Optima. Same thing....

Pulled the starter and bench tested....fine

Looked at the firing order three days in a row after work. Everything looked perfect.....

Pulled the coil wire and it spun free. So I looked at the order AGAIN and noticed I had the #1 wire one post off...making the ENTIRE order off.

Simple test...pull the coil wire.

 

Try turning the engine by hand with a socket and breaker bar. If you rebuilt the engine yourself, my guess is a tight bearing somewhere...

 

aH

 

How would a wrong firing order prevent the engine from turning over?

 

How's your positive battery cable from battery to starter relay look? I'm guessing you checked it after checking all the grounds, but thought I'd ask.

 

[QUOTE]Originally posted by Coogles
How would a wrong firing order prevent the engine from turning over? [/QUOTE thatsProfanity Removedi was wondering would have nothing to do with it. Timming could be set wrong that causes engines to crank slow and pull lots of juice but firing order has nothing to do with it cranking.

 

Thanks for all the good ideas guys, I was able to turn the motor with a socket and ratchet when I had to rotate it around for the torque convertor to flexplate bolts. I had the engine built by a reputable shop, but that doesn't mean he did not over-torque something. I want to say the engine turns the same as when I had to pull it out. I will pull the coil and try that, although i am not sure why that would cause a major power draw, but hell, I'll try anything at this point. Just to make sure; the cylinder numbering order is 1234 on pass side front to firewall, and 5678 drivers side front to firewall right? And I am pulling this from the top of my head, but 15246378 for firing order? It is stamped on the side of the gooseneck intake manifold and I am at work so that may not be right.

 

If you can turn it over with a ratchet and socket I dont think it is the motor, THe firing order you have is right. You may have put the distributor in 180 degrees out. Did you prime the oiling sytem with a drill? Like someone mentioned before, try pulling the coil wire off and try to turn it over.

 

like i said firing order dun have ANYTHING to do with it cranking slow your timming should let it crank faster ( or was it speed it up ).

 

Firing order DOES make a difference in how an engine will crank over. If a cylinder is firing way before it is supposed to it will be forcing the piston the wrong way - slowing cranking down.

Been there, done that.

 

if the engine isn't even turning to fire how can a piston be forced the wrong way lol
if an engine is more than 90 degrees out of time the ignition will simply not let the starter motor kick in or draw to much juice for the starter to turn the motor fast enough cause the advanced timming is hogging the power from the battery.