Milled head mess up timing?

mk3-4-me

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May 19, 2010
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so i milled i think 15 thousandths off my head to get it staright. I threw a stock HG in cause of some short funds. I knew it would be a lil higher compression. That would affect my timing at all would it? my car hasnt been able to start up after the rebuild.
 

hvyman

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Apr 17, 2007
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If that was the only time it was machined it would be ok. Depends if it was ever milled before.

Are you sure that that is your problem?
 

A. Jay

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Jun 3, 2009
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mk3-4-me;1623024 said:
so i milled i think 15 thousandths off my head to get it staright. I threw a stock HG in cause of some short funds. I knew it would be a lil higher compression. That would affect my timing at all would it? my car hasnt been able to start up after the rebuild.

My cylinder head has 15 thousandths shaved off, runs perfect.
 

JonnyZ(Socal)

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Apr 12, 2010
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Well 15 thousandths wouldn't cause your car to not start if that is all that has been removed... My head had 20 thou. taken off when I bought it (i didn't know at the time) with a stock hg and it started like a brand new car. Did you check all of the basics first? Battery, spark, cps, etc!!!
 

shaeff

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I'd doublecheck timing. Most of the "it doesn't start after rebuild" threads are due to a mistimed engine. Check that the CPS connector is fully engaged, and that there's no broken wires or shorts in that area. The CPS is constantly heat cycled, along with all the wires in that area because it's so close to the exhaust/turbo. Verify everything.

Check the articles section for a how-to on timing, just to make sure you've got it all properly set.
 

Asterix

Lurker of Power
Mar 31, 2005
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After a bit of drawing the crank pulley and cam gears in a 2D CAD package, I can say that shaving 0.030 off a head will result in about 1 degree of timing error between the crank and valves. That's not enough to keep the engine from running.
 

jstricker

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Sep 10, 2010
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Check your compression. If your cam timing is off your compression will be as well. It's not that hard to have a brain fart and know beyond any doubt that you 'did it right' and someone else looks at it revealing you had a real "duh" moment.

If your engine has:

Fuel
Compression
and
Spark at the appropriate time

IT WILL RUN. Poorly, perhaps, but it will run. If it's not even trying then it's lacking one of those three things.

John Stricker
Russell, KS
DOGMA Racing
 

Ozz89supra

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Feb 22, 2009
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^ exactly man, after my build I could not start my car either, and it turned out to be my timing. Double check the CPS and make sure the timing is set correctly. If everything is in time it should fire up. Mine did and idled perfect (after spending an hour adjusting the CPS and timing belt). As far as the milling I have never heard of that before. Even if you milled it quite a bit I highly doubt it would affect the timing so much that it would not fire at all. Hopefully you can figure out whats wrong. Good luck!
 

boostcraver

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Mar 13, 2010
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You never said if the car was cranking or not. If it is cranking, does it TRY to fire and just not quite get there? You said you had fuel, but is your fuel system at 100%? Low fuel pressure could cause a failure to start even if you technically have fuel at the rail. IIRC, the pressure while cranking/ running should be 47-60 psi. How about vacuum lines. Are they all new and hooked up correctly? Vacuum leaks are bad and could definitely contribute to the lack of starting. Is it possible that you set the cps housing back where it was but set the gear/rotor assy. 180* off? I did that when I put my old 7m back together after the gasket change ( it's easy to do) and it wouldn't run either. If nothing else works, try removing the cps (gear and all), turn the gear 180* then reinstall it and try it again. You might be pleasantly surprised to have it start after all and if it doesn't work, at least it didn't cost anything! Simple things to check but worth the time to do it, and even the most experienced mechanics miss the little things from time to time. Good luck!
 
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boostcraver

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mk3-4-me;1623474 said:
it does "TRY" to start with a couple lil putts here and there. I dnt have anything to check for the exact fuel pressure either.

If it is trying to start, I would recommend trying the reversal of the CPS gear/rotor assy. first. That's what my '87 did when the CPS was 180* off. Flipped it back around and she fired right over. If that doesn't work, check with the local auto parts store in your area and see if you can get a fuel pressure tester on some kind of loan-a-tool program. It shouldn't be too expensive. If there is a Harbor Freight tool store close to you, they carry them for under $20 for a basic kit. It would be a worthwhile investment as you WILL need it again if you plan on modding your car in the future.
 

mk3-4-me

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May 19, 2010
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I LOVE HARBOR FREIGHT FOR CHEAP TOOLS!! LOL but ok everyone is telling me to try flipping the cps 180*. I am positive i timed it right. 0* TDC with cam lines pointing up, i lined up the notch on the cps and put it in. When its in and i have the cover off it looks like this
p1623711_1.jpg


And even after all this, could it still not be starting cause its 180* off? I just dont see how it could be off. Idk thanks for the help though, gas tank is out now anyways so i cant really try it now. lol
 

bombinuass

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Mar 20, 2010
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it MAY not be off. , but i know it only takes 30 mins to take the cps out and retime it. so what do you have to lose? Considering this thread is 3 days old and for 3 days everybody says TIMING. so 30 mins?

---------- Post added at 08:40 PM ---------- Previous post was at 08:38 PM ----------

also, is there anyone in your area that may have a spare cps for you to test? or do you have one?
 

boostcraver

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Mar 13, 2010
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mk3-4-me;1623711 said:
I LOVE HARBOR FREIGHT FOR CHEAP TOOLS!! LOL but ok everyone is telling me to try flipping the cps 180*. I am positive i timed it right. 0* TDC with cam lines pointing up, i lined up the notch on the cps and put it in. When its in and i have the cover off it looks like this
p1623752_1.jpg


And even after all this, could it still not be starting cause its 180* off? I just dont see how it could be off. Idk thanks for the help though, gas tank is out now anyways so i cant really try it now. lol

If this is in fact the CPS that is currently mounted on your car, then you may not have exactly the problem that I hypothesized. If the base timing is to be 10*BTDC, You may only need to slightly adjust the housing to dial it in a little better. When you get your tank back in, that is. I responded to your other thread about the tank in the general discussion section as well. Hope I have been helpful between the two threads. Good luck!