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-   -   Timing Belt Troubleshooting...Help? (https://www.miataturbo.net/engine-performance-56/timing-belt-troubleshooting-help-52359/)

BoostedTrixx 10-06-2010 08:32 AM

Timing Belt Troubleshooting...Help?
 
Started in on my 3rd timing belt job on my homebrew turbo 94, went and got a full front timing cover gasket set, and cam seals. I've done quite a few timing belt jobs in my day on interference and non-interference engines and 2 already on this particular car. The gasket/seal installs went smooth as could be, replaced the timing belt.

No start...loud pop. :facepalm:

I get back out double check my plug wires/firing order...rotate the crank by hand 2 revolutions and all 3 timing marks are on the dot! Car still wont start...I cant figure out what it is to save my life, it MUST be something in the timing, there are no other factors that I have altered/changed (megasquirt cranking settings, ignition timing).

I checked for TDC on the compression stroke, lined up the crank timing notch, took the cam gears off and rotated the cams to have the dowels on the cams at the top, then placed the cam gears on with the appropriate letters facing up as well to match the dowels. (E on the left cam, I on the right cam). Rotated the cams to match the timing marks on the plate and the crank to match the notch, slipped the timing belt on and tightened, and still NO START...:vash::vash:

Anything I am missing as far as timing this thing?!?! help please? I can take pictures of everything if need be. Never had this problem before.:sadwavey:

BoostedTrixx 10-06-2010 08:37 AM

I even have AllData (commercial repair manual program for computer), and double checked on there for firing order, and that I had the correct timing marks and procedure. Still coming up with fail.

olderguy 10-06-2010 08:51 AM

You removed the cam gears to replace the seals. Check to see that the pins in the ends of the cams relate to the marks on the cam gears correctly.

Braineack 10-06-2010 08:55 AM

sounds like you are 180 out... sure you have the cams pointed in teh right direction?

BoostedTrixx 10-06-2010 10:01 AM

Would they still show up right on point after 2 revolutions of the crank? I can spin it over and they all 3 points match up. 180 on the crank or the cams? I took the cam gears off to replace the cam seals, and when I reinstalled I turned the cams so that the dowel pins were pointed up (at the top) and did the same with the cam gears too I have the "I" pointing up on the right side and the "e" pointing up on the left side when I reinstalled, I then turned them to meet the timing marks.

A good way to double check if I'm 180 out?

BoostedTrixx 10-06-2010 10:02 AM

Anybody know why the exhaust cam lines up with I on I but the intake lines up on the e's?

Braineack 10-06-2010 10:25 AM

that's the way it should be. it's because the exhaust cycle is about to start and intake cycle just ended or something.

the first lobe on your cams so both be horizontal at this position and facing outward.


with #1 at TDC, this is how everything should look:

http://lh6.ggpht.com/_4r9t1ln5Huc/S9...0/DSCF6171.JPG

http://lh3.ggpht.com/_4r9t1ln5Huc/S9...0/DSCF6170.JPG

http://lh4.ggpht.com/_4r9t1ln5Huc/S9...0/DSCF6168.JPG

olderguy 10-06-2010 11:22 AM


Originally Posted by BoostedTrixx (Post 639472)
Would they still show up right on point after 2 revolutions of the crank? I can spin it over and they all 3 points match up. 180 on the crank or the cams? I took the cam gears off to replace the cam seals, and when I reinstalled I turned the cams so that the dowel pins were pointed up (at the top) and did the same with the cam gears too I have the "I" pointing up on the right side and the "e" pointing up on the left side when I reinstalled, I then turned them to meet the timing marks.

A good way to double check if I'm 180 out?

Methinks you should have had the "I" pointing up on the intake or left side and the "E" pointing up on the exhaust or right side when the pins were in the up position.

RyanRaduechel 10-06-2010 11:37 AM

brains pictures show it best for the markings on the cams and the notch in the crank pulley, it sounds 180 out to me also..good luck. Did you put it all back together with all the covers and what not and now have to tear it back apart?

BoostedTrixx 10-06-2010 07:08 PM

2 Attachment(s)

Originally Posted by Braineack (Post 639485)
that's the way it should be. it's because the exhaust cycle is about to start and intake cycle just ended or something.

the first lobe on your cams so both be horizontal at this position and facing outward.


with #1 at TDC, this is how everything should look:

http://lh6.ggpht.com/_4r9t1ln5Huc/S9...0/DSCF6171.JPG

http://lh3.ggpht.com/_4r9t1ln5Huc/S9...0/DSCF6170.JPG

http://lh4.ggpht.com/_4r9t1ln5Huc/S9...0/DSCF6168.JPG



Heres what I've got, I can see where you say possibly 180 out. Ive still got the water pump pulley on at the moment cause I just reassmbled it all so I wouldnt be able to take a pic of the crank pulley in line, but with the crank lined up and the cam timing marks lined up, this is what I have and where the first lobes are.

Attachment 193719

Attachment 193720

olderguy 10-06-2010 08:05 PM

Looks like the cam gears were mis-mounted on the cams

shuiend 10-06-2010 08:23 PM

If those pictures are at TDC then yes you cam gears are off. Take off each cam gear. Put knock pin pointing up. Reinstall cam gears with the "I" pointing up on intake side, and "E" pointing up on exhaust side.

BoostedTrixx 10-06-2010 08:58 PM


Originally Posted by shuiend (Post 639789)
If those pictures are at TDC then yes you cam gears are off. Take off each cam gear. Put knock pin pointing up. Reinstall cam gears with the "I" pointing up on intake side, and "E" pointing up on exhaust side.

Did exactly this and she fired right up!

The mistake was when I went to take the cam gears off I didnt mark the spots on the belt and cam gear before I loosened it (rushing shit as usual), and the exhaust cam gear fell off before I marked it.

Thanks for all the info/tips/pointers guys...this thread has some useful pictures as far as where the lobes on the cams should be pointing in relation with the "I" and "E" on the gears. Hopefully somebody else can reference this info if need be someday.

shuiend 10-06-2010 09:01 PM


Originally Posted by BoostedTrixx (Post 639810)
Did exactly this and she fired right up!

The mistake was when I went to take the cam gears off I didnt mark the spots on the belt and cam gear before I loosened it (rushing shit as usual), and the exhaust cam gear fell off before I marked it.

Thanks for all the info/tips/pointers guys...this thread has some useful pictures as far as where the lobes on the cams should be pointing in relation with the "I" and "E" on the gears. Hopefully somebody else can reference this info if need be someday.

Glad that it is fixed.

chicksdigmiatas 10-06-2010 09:54 PM

LOL a quick easy check i have always found to work, is to make sure all the pins are at 12 o'clock.

therieldeal 10-07-2010 01:23 AM

i screwed this up my first timing belt job as well, lol. of course this was combined with a first time MS install, complete with no pullup resistor on the CAS input (i didnt build it..). and i ended up burning up both a battery and a starter before i figured both issues out. whoops

hustler 10-10-2010 08:47 PM

Does CAS position usually change with the timing belt instal? I've been chasing a problem for two days now with the synchronization and my timing light is dead so I can't check spark angle. "All pins are pointed up" and the car is still rough. The last possibility is damaged spark plug wires.
http://i55.tinypic.com/24qsvi9.jpg

shuiend 10-10-2010 09:22 PM


Originally Posted by hustler (Post 641315)
Does CAS position usually change with the timing belt instal? I've been chasing a problem for two days now with the synchronization and my timing light is dead so I can't check spark angle. "All pins are pointed up" and the car is still rough. The last possibility is damaged spark plug wires.

I do not think that the CAS positions change with a timing belt install. As long as you did no remove the CAS it should still be good.

hustler 10-10-2010 09:45 PM

Damn, something is screwed up.

shuiend 10-10-2010 09:46 PM


Originally Posted by hustler (Post 641325)
Damn, something is screwed up.

This the track car or the DD? Can you give more details of how it is running rough?


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