I got the motor back from the builder and everything is back in. I hand cranked it while the timing belt was put on, and it turns like normal, maybe a bit harder.

Now that the battery is back in and all, the first crank was really slow. It turns slow, fires, but not fast enough. Thinking that it was the battery, I had two different cars try to jump start it. Still a slow crank. I even tried a new battery, still the same. The starter was tested, and it turns normally, just not in this motor. I cleaned the grounds and even added new ones; no dice.

Giving up on the starting system, I even did a push start. The engine wants to go, but it doesn't move fast enough. I checked the hand crank again, still okay.

I thought this should go into forced induction since this is a low compression engine rebuild issue.

 

have the checked the timing belt to see how tight it is?

 

Yeah, it's good and so is the alternator. Timing belt and alternator are the only belts on the motor.

 

how good are the grounds? make sure they adequate especially if the battery is relocated.

 

I am having the same problem. Did you try new connectors for the battery terminal and check your spark

 

It fires as it turns, just too slowly to get it to idle speed. I cleaned the grounds, even tried different ground wires. No luck there either.

 

maybe the map sensor is switched with iacv or your tps is off calibration. or bad spark wires!

 

With the spark plugs out and out of gear you should be able to crank over the engine by hand. Do that to make sure something isnt restricting rotation.

 

I can turn it over with a wrench. There is the usual resistance from the cam lobes, but aside that, it turns nicely. Has anyone had this problem with a newly built motor?

 

bump. still having this issue. Ran a new battery and starter, got a little faster crank, and about 25psi of oil pressure, but it won't run.

 

U didnt foul your plugs out while trying all of this did you? Bad gas? No spark? No injector pulse?

 

3rd set of plugs. I checked spark, grounded the plugs to a ratchet on the valve cover, 4 were ok. fuel is good, rail pressure is clean, ~44psi.

 

i had the same problem and the starter checked out good but i swaped for a used one my friend had and it ran great

 

i had same problem on newly built motor.. turn out to be the rod bearings didn't have enough clearance . so it had alot of drag while cranking.

 

where are these located? are the connectors the same? Could you post a picture or detail so I know if i have these switched?


Bump because i have the exact same problem.

All i did was swap all the good parts on my blown motor to a used motor that supposedly was good.
Turns freely
Timing belt is good and dead on.
Firing order is correct. Cap and button are new.
It's getting fuel (how do i check the pressure?)
All 4 plugs are sparking.
Starter worked fine when on my old motor.