Need help with finding TDC

[Guest thekingofcrunk17]

i replaced a timing belt and water pump on my '91 Honda CRX, that was the easy part... i cant find the Top Dead Center in my No.1 cylinder. the camshaft is really easy it has marks on the pully to tell you where to align it, but im having trouble finding the TDC. I've taken this motherf-er apart about 3 times and put back together (to try and start it) and its always been off... thanks for the advice

[Mojoe]

i replaced a timing belt and water pump on my '91 Honda CRX, that was the easy part... i cant find the Top Dead Center in my No.1 cylinder. the camshaft is really easy it has marks on the pully to tell you where to align it, but im having trouble finding the TDC. I've taken this motherf-er apart about 3 times and put back together (to try and start it) and its always been off... thanks for the advice

 

 

Please go to the classroom and do an introduction so we get to know who we are helping.

[Jelloman4571647545499]

pull the spark plug and put screwdriver in hole. Watch screwdriver move up and down as you rotate the engine by the crank pulley. Watch it go up and down and watch for the top. this is the fastest most redneck way.

[MrMeanGreen]

Put your finger over the spark plug hole for that cylinder and have someone crank the engine using a breaker bar. When your finger is blown off from the compression, there ya go.

 

Layman's way of doing it.

[Clifford Automotive]

Put your finger over the spark plug hole for that cylinder and have someone crank the engine using a breaker bar. When your finger is blown off from the compression, there ya go.

 

Layman's way of doing it.

 

 

Ditto, if your not comfortable with the screwdriver method.

[MrMeanGreen]

I just shy away from the screwdriver method as not to risk scarring the crown of the piston.

[Guest Hal]

I would use the screwdriver method, but I guess that's 'cause my ford pistons are better than Anthony's

[MrMeanGreen]

Eat me, Hal

[Guest Hal]

Are you trying to seduce me?

[Guest thekingofcrunk17]

does it matter if the crank is on the compression or the combustion stroke? cuse either way the crank does the same thing for both aslong as the spark plugs are sparking when the piston is up right...?

[351mach11647545510]

compression

[Guest thekingofcrunk17]

alright how do i know its on the compression stroke? and is there any other ways that would be more accurate on finding the TDC??? thanks

[351mach11647545510]

Put your finger over the spark plug hole for that cylinder and have someone crank the engine using a breaker bar. When your finger is blown off from the compression, there ya go.

 

Layman's way of doing it.

 

or take the valve cover off and look for the intake valve and find it that way.

[Guest Hal]

alright how do i know its on the compression stroke? and is there any other ways that would be more accurate on finding the TDC??? thanks

 

Both of the ways mentioned will work well. If you want to be sure it's the compression stroke, Anthony's way will be easier.

[Guest thekingofcrunk17]

Both of the ways mentioned will work well. If you want to be sure it's the compression stroke, Anthony's way will be easier.

 

will this work if the timing belt is off and the cam is set for the crank to be at the TDC?

[Guest Hal]

You're going to think every stroke is the compression stroke if the cam is set with the valves closed. I would revert back to the screwdriver method. If you are worried about scoring the piston, just wrap a little duct tape around the end to soften it.

[351mach11647545510]

does the car have a distributor?

[baron_]

i'd be hesitant to put anything around the bottom of the screwdriver

 

if it comes off, you'll have to take the head off to get it back out

(in other words - don't)

have a buddy help with the screwdriver so you don't get it bound up or hurt anything

 

or just use ant's way and put it back together

test with the screwdriver when you get close (once you've felt the puff of air) and adjust the crank accordingly

 

fire it up and if it sounds wrong, you're 180 off - no big deal

if it's distributor driven, take out distributor, rotate 180 and you're golden

[Guest thekingofcrunk17]

will it start at all if its 180 off cuse i worked on it today like an hour ago, did the screwdriver thing and it wouldnt start so im gonna assume im 180 off or something else is wrong...

[Guest thekingofcrunk17]

does the car have a distributor?

 

yea it does but it shouldnt be miss timed its never been touched

[baron_]

yes, it should probably start

but it'll sound ridiculously pitiful

 

depends on a lot

a smaller motor might not start

 

 

i know for a fact my 400 inch v8 started 180 off

[verse]

Put it at TDC before you pull the belt and you wouldn't have the problem in the first place.

 

Anthony has given a good suggestion though.

[Clifford Automotive]

Put it at TDC before you pull the belt and you wouldn't have the problem in the first place.

 

Anthony has given a good suggestion though.

 

What if it broke and thats the reason he is replacing it? He'd still have the problem.

[Guest thekingofcrunk17]

yea... well i guess im gonna try and put it in TDC and crank it 180 degrees cuse it wont start so im guessing its 180 off... if not its a peice and i need to find what else is wrong

[verse]

What if it broke and thats the reason he is replacing it? He'd still have the problem.

 

Well if it broke he's taking the head of b/c the 1.6 in a CRX is an interference motor. Not to mention if he tried to crank it over with the timing off, which it sounds like he has tried.