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-   -   Quick timing question (https://forums.tbforums.com/showthread.php?t=340913)

1rockhead 03-30-2018 09:42 PM

Quick timing question
 
I just finished my first timing belt change. It started right up. Seemed to stumble a little bit on acceleration. I only let it run for 30 seconds or so due to the acc belts not hooked up. The crank timing mark was a hair off when i reassembled. Do you think i should redo it or will the computer compensate?

1rockhead 03-30-2018 09:42 PM

Oh 1990 volvo 240

esmth 03-30-2018 10:53 PM

Can't you just check if the timing marks line up? you may need to spin the engine a bit to re-line up the marks on the belt with the gears, or you could count the teeth.

One tooth off is what, 14 degrees? you'd definitely be able to tell it isn't running right if that were the cause.

quillc 03-30-2018 10:57 PM

it likely wouldn't run at all if you were a tooth off on the crank.

check the timing with a timing light.

MasterBlaster 03-31-2018 03:58 AM

Quote:

will the computer compensate?
Nope.

Quote:

it likely wouldn't run at all if you were a tooth off on the crank.
Sure, it would still run (maybe), but just barely.

The best way to check is to take both covers off and check all the marks, but if you're sure the outer ring hasn't slipped on the hub, you can use the marks on the balancer's pulley and the lower cover to put the crank at TDC. Then check the marks on the big shiny sprockets in the following link. On my car (head mounted distributor), only the top and bottom pulleys matter, but on yours (block mounted "normal" distributor), all 3 need to be correct.

Pics linked from:
http://www.threefattigers.com/Protoc...imingMarks.htm

Cam:

http://www.threefattigers.com/Protoc...B230TM-Cam.jpg

Auxiliary shaft (drives your distributor):

http://www.threefattigers.com/Protoc...termediate.jpg

Crank:

http://www.threefattigers.com/Protoc...0TM-Crank1.jpg
http://www.threefattigers.com/Protoc...0TM-Crank2.jpg
http://www.threefattigers.com/Protoc...M-Crank2b.jpeg

1rockhead 03-31-2018 02:32 PM

That last picture really helped. Checked again and all timing marks were lined up at it is running great. One question still, is it normal that the lines on the belt no longer line up to the Timing marks on the sprockets?

soclosenotnear 03-31-2018 02:45 PM

Quote:

Originally Posted by 1rockhead (Post 5775989)
That last picture really helped. Checked again and all timing marks were lined up at it is running great. One question still, is it normal that the lines on the belt no longer line up to the Timing marks on the sprockets?

yes

ZVOLV 03-31-2018 02:54 PM

Quote:

Originally Posted by 1rockhead (Post 5775989)
That last picture really helped. Checked again and all timing marks were lined up at it is running great. One question still, is it normal that the lines on the belt no longer line up to the Timing marks on the sprockets?

Turn the engine 5000 times by hand and they will line back up.

1rockhead 03-31-2018 04:58 PM

Great. Thanks for the help

1rockhead 05-12-2018 11:58 PM

So everything was fine... Went to start it tonight and wouldn't fire up. Sounds the same as before. Assuming I did the Timing belt right is there something else that can cause the tbelt to slip?

1rockhead 05-12-2018 11:59 PM

I have put maybe 100 miles on it.

1rockhead 05-13-2018 12:02 AM

Oh and i replaced the tensioner also

VB242 05-13-2018 07:29 AM

When you put the belt on, you need to turn the engine over by hand at least one full cam revolution and then retension the belt.

1rockhead 05-13-2018 10:21 AM

I retensioned after a few test drives.

1rockhead 05-13-2018 12:03 PM

Thinking the cam may be binding a bit. Tried turning the engine over at crank and the cam would not turn until I put a wrench on that also. Once i turned it one revolution it turned fine by the crank bolt only. If the cam is seizing does that mean I need a new head?

1rockhead 05-13-2018 03:03 PM

Camshaft looks fine. Bearing caps seem fine. The new belt did have at least one missing tooth.

1rockhead 05-13-2018 09:27 PM

Intermediate shaft spins freely. There was a small amount of belt remnants on the tensioner pulley but it still spins freely. Any ideas?

Otto Mattik 05-14-2018 02:50 AM

Quote:

Originally Posted by 1rockhead (Post 5795867)
Camshaft looks fine. Bearing caps seem fine. The new belt did have at least one missing tooth.



A) replace with new belt

B) also I would follow VB242 advice and retension belt in that manner

MasterBlaster 05-14-2018 09:12 PM

Quote:

Originally Posted by 1rockhead (Post 5795812)
the cam would not turn until I put a wrench on that also.

The new belt did have at least one missing tooth.

There was a small amount of belt remnants on the tensioner pulley but it still spins freely.

Can I assume you used the proper belt?

Yours should have the "square" teeth to match your 1990.
In 1993 they went to a "round" tooth style (as seen in the above pics).
Not compatible unless you also change all the sprockets.

I also assume you didn't over/under-tension the belt?
The normal procedure (how I do it) is to remove the rubber plug in the belt cover, loosen the tensioner nut with a socket (1/2 turn or so), turn the crank slightly clockwise to pull the non-tensioner side of the belt tighter, (and allow the tensioner's spring to take up any slack), then retighten the nut to 37 ft-lbs.

Here's a crank sprocket comparison, borrowed from another post:
http://www.forums.turbobricks.com/sh...d.php?t=198536

http://oi66.tinypic.com/13z721k.jpg


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