rebuilt hard to crank (high engine resistance); need advice

[cbrewster]

rebuilt hard to crank (high engine resistance); need advice
I have just finished putting my 88 Toyota Supra back together and the engine is labouring to start. I bought the supra with a damaged 7mge...it had spun a rod bearing. I bought a replacement 7mgte out of an 87 Supra, re-built it and dropped it into the 88 Supra. I reconnected the original automatic transmission off the 88 and have recently tried to start it for the first time.

Initially I started the car with the spark plugs removed and let it crank for approximately 15 seconds to get the oil pump moving. The engine cranked normally for this amount of time and everything sounded good. I then replaced the spark plugs and tried to start the motor. Initially the engine cranked normally and it seemed to want to start however, pretty soon the engine started to drag and it acted like it was not getting enough power to the starter. Thinking that the battery was just going dead I put it on a charger and returned the next day to try again. The next day I tried to start the motor only to have the same results...the engine labored to turn and it seemed like the battery was half dead.

The next day I borrowed two extra batteries from work and with three batteries connected, I tried to start the engine again. I had the same results with the engine experiencing high resistance to turn. At one point I measured 800 amps (yes that number is correct) into the starter. It was after this point I stopped and realized that something was causing the engine to have high internal resistance.

What could I have done during rebuilding the motor and installing the transmission to cause it to be hard to turn? I tried turning the crank pulley with a wrench and found it impossible to turn...should the crank be easy to turn by hand with a wrench? (I am pretty sure it should be but I am just double checking).

Obviously I have taken all precautions and took the proper steps during my rebuild...I am using heavy weight oil in the motor and there are no leaks in the system. I cannot check the oil pressure with a manual gauge at this point because the engine will not crank. Is there another way to see if the oil pump is working?

Any advice in helping me trouble shoot this problem will be greatly appreciated.

[DarkSupra2.5]

Have you tried pulling the spark plugs back out and cranking it without them again? Your cylinders may be filling with something. At best, maybe your oil is to thick, at worst, you may have to pull the engine back apart. Cause even if the oil pump had failed, you'd be able to at least start it once before it seized up.

[Bill UK]

As DarkSupra 2.5 said "try it without the plugs again," and recheck the cam pulleys and crank pulley are in there correctly position.

[cbrewster]

Thanks for the replies...I took the spark plugs out when I first noticed the engine was struggling to turn.

I am starting to suspect that the transmission is the cause of the problem. I had a lot of trouble installing the transmission because I could not get it lined up properly. I borrowed a transmission jack (something I should have done in the first place) and I plan on taking it out and seeing if that frees up the crank shaft. If this doesn't work, then I will try checking the timing belt, cam gears, crank pulley, etc.

I sure hope one of these two methods will fix the problem...if not, then I might have a car available for parts! I will let you all know what the progress is. Thanks again!

[cbrewster]

OK...I think I have figured out what the problem is. The 7mgte I had purchased to put in my 88' Supra originally was paired with a manual transmission. My 88' Supra has an automatic transmission...so long story short, I forgot to remove the pilot bearing from the crank shaft before I installed the AT. This explains why the AT was so hard to install the first time around and why it progressively got harder to turn.

I just hope I did not do any great damage to my rebuilt 7mgte! I took the AT out this weekend and after removing the badly damaged pilot bearing, I took crud measurements of the starter gear and torque converter. Everything seems OK not to mention the AT was much easier to install and the crank turns nice and smooth. I don't have the car completely back together yet, but I am hoping not to have too many more problems on my way to getting it running.

Anyhow...have this be a lesson to everyone! If you are moving from a manual transmission to an automatic transmission, be sure to remove the pilot bearing from the crank shaft!!!

Thanks for all the great suggestions and help! BTW, if anyone thinks of some additonal checks I should make on the engine or AT for damage, please let me know.