spike

I wanted to compression test the motor I just got from Osaka, but it is no where near being ready to put in the car.. (missing motor mount, etc) I thought just giving the starter power from the battery would turn it over, but I was wrong. There seems to be a small plug on the starter as well.. is this the signal to allow the starter to go once it has power? How can I get this thing to turn over without hooking up the ecu and everything else?

Thanks for the advice!

PM-Performance

have someone with really fast hands get on the crank pulley with a socket.

J/k . im curious too.

spike

hahah.. we tried that when the trans wasn't on.. no freakin' way you can get that thing spinning fast enough.. we maxed out at like 90pis by hand.

Also, are there any negative side effects of doing this? There is coolant in the motor, but there is still oil.

dasher

the starter is grounded to the transmission, the transmission needs to be grounded also via a transmision ground ... connect the starter to a constant 12 V source through terminal B , and send a brief 12 v current through terminal S (selenoid terminal))small terminal on side of starter ...

it will work

// coolant not needed // make sure their is oil

B18C1CYA

maybe if the trans and starter are hooked up you could use one of them battery chargers with the start feature and just hook it on the starter termanials, it might be tricky but i think this could be the only way

dasher

just use the car battery ... ive done this before..

spike

ok.. so i have to give that little male wire connector thing a short 12v signal? Will it only turn when there is voltage to this? Or is that just to get it going?

Thanks man!

99B16Si

if u have access to a leakdown tester theyre more accurate anyway

dasher

as far as signalling the starter ... simply connect one wire to the positive terminal on the battery and the other side you can touch the bare wire to the S terminal .. you will hear it kick over ...

the starter will recoil when you touch the s terminal with 12 volts

likewise , you can also test starters this way outside of the transmission.. you just have to make sure the starter casing is grounded ...

B18C1CYA

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99B16Si &raquo;</TD></TR><TR><TD CLASS="quote">if u have access to a leakdown tester theyre more accurate anyway</TD></TR></TABLE>

dasher

leakdown tests are better ... but not everyone has a compressor...

spike

excellent.. thanks for the info! I just don't want to shell out the $100 for a leakdown tester I'll use once.. The idea of getting one and returning it to pep boys has been tossed around however..

Muckman

iTrader: (2)

Technically you can wire up a car battery to the alternator and crank it over. Sort of like hot wiring a car. Ive seen a really smart car guy do it once but I dont know which wires he used to get it to crank over.

roydogg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">leakdown tests are better ... but not everyone has a compressor...</TD></TR></TABLE>

Sorry for the noob question but how do you do a leakdown test on a motor with no trans on a engine stand? Do I need to put every cylinder in tdc?

dasher

yep, you place each cylinder tdc individually just like you do with the engine in the car... same process

roydogg

Thanks for the quik response .

Stewie

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spike &raquo;</TD></TR><TR><TD CLASS="quote">excellent.. thanks for the info! I just don't want to shell out the $100 for a leakdown tester I'll use once.. The idea of getting one and returning it to pep boys has been tossed around however.. </TD></TR></TABLE>

Trust me, if you got a leakdown tester, I guarantee you won't use it just once. It's one of the best tools I own.

GDM Z28

if u do a comp check while the motor is cool wont it be in acurate? i thought a motor had to be hot when u did it and you had to do it while holding WOT?

VTC_CiViC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicflnum1 &raquo;</TD></TR><TR><TD CLASS="quote">if u do a comp check while the motor is cool wont it be in acurate? i thought a motor had to be hot when u did it and you had to do it while holding WOT?</TD></TR></TABLE>

It won't give a true value of compression since the piston hasn't expanded while sitting cold, but it'll give you a ball park.

GDM Z28

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTC_resurected_CiViC &raquo;</TD></TR><TR><TD CLASS="quote">

It won't give a true value of compression since the piston hasn't expanded while sitting cold, but it'll give you a ball park.</TD></TR></TABLE>

why u stalking me?

093turbo16

iTrader: (2)

you can do it with an old school battery charger too. Do it on my RX7 sometimes, ha.