Um, is my timing messed up or what?

[vtluu]

So, at Bryan's insistence (nagging) I checked the timing in my somewhat-unhealthy Evo...

Cam gear timing marks lined up (don't mind the perspective; they're lined up, trust me):

http://www.norcalevo.net/gallery/albums/album434/timing1.jpg

Timing mark on crankshaft pulley:

http://www.norcalevo.net/gallery/albums/album434/timing3.jpg

Close-up:

http://www.norcalevo.net/gallery/albums/album434/timing2.jpg

:? According to what I've read, the leftmost of the 4 marks is 10 degrees BTDC, the rightmost (hard to see so I highlighted it in green) is TDC. Supposedly a couple degrees off TDC from the factory is normal. But from the looks of it, I'm over 10 degrees BTDC. :shock: Is my timing off by a tooth (or two)?

[Eclipse]

Those marks are for checking the ignition timing. I'm not sure how it compares to the marks on the front case and actual crankshaft sprocket. I think you should take off the lower shield and check those if you are really worried about your cam timing.

I thought Bryan wanted you to check your base ignition timing?

I hope that helps a touch.

[vtluu]

I thought Bryan wanted you to check your base ignition timing?
Yes he did, newbie me isn't aware of the difference between ignition and cam timing. But I'm pretty sure this is what he wanted me to check, and as I said I'm a n00b at this but it doesn't look right to me...

[Option2]

When you say "unhealty" Evo, what do you mean? Are you experiencing rough idle?

The reason I ask is because I just had my head rebuilt. I had a bad valve guide on my #4 exhaust valve. The wear was so bad that I had about 1mm of play on one of my exhaust valves.

I found out I had this issue when I dynoed my car at Gruppe-S. Mike told me my idle wasn't quite right. He said it sounded like it was misfiring. I also had low dyno numbers for the mods I have (TR340). I took the car to WORKS and they did a compression test. It turns out that I had low compression on #4. They performed a leak down and narrowed it down to the exhaust valves.

[XVeloX]

holy shit! ya you are definately off by a tooth or two, ive installed cams twice and ive been BTDC before the install by about 2 degrees and 4 degrees...

If you can definately should push the timing back dude, thats messed up. Not sure how much 1 tooth does, start with that...holy shit.... i didnt think it would jump THAT far lol

[Eclipse]

Well to do you have a timing light? Do you have a scanner or something to hook up to OBD port and go to diagnostics? Can ecu + do this? The manual doen't show any other way to check. On my dsm all you need to do is ground a connector with jumpers.

[Matz]

I thought Bryan wanted you to check your base ignition timing?
Yes he did, newbie me isn't aware of the difference between ignition and cam timing. But I'm pretty sure this is what he wanted me to check, and as I said I'm a n00b at this but it doesn't look right to me...

I'm a newb, too. Maybe Bryan meant that you should look at your ignition timing in the ECU+? Ignition timing is for the spark, and cam timing is for the valves. I would think that you don't want to be off on the cam timing or you may demolish your valves and pistons. :?: From what I've read on evom about cam timing, yours looks way off... :shock:

[dohcvtec]

No, Bryan wanted him to check cam timing. I've been in coversation with Bryan about Tams issues for a while now. You should first line up your crank to TDC (green line) and then adjust your cam timing accordingly. That will for sure make your car run like poop by having your cam timing off by that much. Who did your cam install?

[vtluu]

I'm still on stock cam and cam gears (but I picked up the Helix cam gears today :twisted:). Nobody should have touched the timing belt or cams since I've had the car.

I double-checked the timing again. Turned the crankshaft around (in the correct direction) a bunch of times. Basically there's a 2-to-1 ratio between the crankshaft and cam gears. Every time I would line up the crankshaft pulley mark to TDC, the marks on both cam gears would show up exactly 1 tooth off. I checked using the "screwdriver in cylinder 1" method, and the TDC using that method seemed to match up exactly with the TDC mark on the timing belt cover. No getting around it, my timing was off.

So I did a bit of research on EvoM and decided to try the "dirty cheating bastard" way of fixing my timing: turn the crankshaft and slide a thin strip of metal between the cam gear and timing belt. This allowed me to (with a breaker bar and socket) correct the timing on both cam gears (basicaly each one needed to be adjusted 1 tooth counter-clockwise).

I reset the ECU and then fired up the car, and took it out for some testing. The first thing I noticed, on the way to my preferred "testing site", was that the car no longer runs like crap at low RPMs. For example doing 45 in 5th gear no longer causes really bad droning; the car is less prone to stalling when just rolling around at low RPMs (e.g. in a parking lot) and suddenly lifting off; I get much less weird "chatter" from the driveline when short-shifting up.

Did some pulls and what do you know, I'm up about 35 whp, and about the same lb-ft of torque. :shock: Torque no longer drops like a rock as I'm approaching redline. Knock activity seems more reasonable. Timing still seems a bit more bumpy than I'd like, though.

I'm pleased. Finally some positive results from my car after weeks of trying to pin down the problem. :)

[Eclipse]

Sorry to add to the confusion then. If you are going to do cams then a full timing belt job probably would be a good idea on your car.

OBD2 looks like it adds to the complexity. A simple job like setting base timing requires a real diagnostic scanner. :?

[earlyapex]

FINALLY IT'S RUNNING RIGHT

#3 is with the timing fubared, #2 is after it was fixed:

http://www.norcalmotorsports.org/users/bryan/mods/EVO/TAM_badtimingVSgoodtiming.gif

Now lets get that car CB'd! :D

[Matz]

Nice work, Tam! I'm glad to hear that this weird problem has finally been resolved. Now add 272s and get the CB340 sticker on your side window. I'm right behind you!

[ace33joe]

Hey, Tam. I am glad that you got the problem fixed. What are other symptoms of the timing problem? Recently my exhaust smells bad when idling (stock cat, 18,000 miles) (when engine is fully warmed-up). I also feel kind of less power. Maybe my timing is also slightly off?

[vtluu]

Hey, Tam. I am glad that you got the problem fixed. What are other symptoms of the timing problem? Recently my exhaust smells bad when idling (stock cat, 18,000 miles) (when engine is fully warmed-up). I also feel kind of less power. Maybe my timing is also slightly off?
I can't say that all the following problems were caused by the timing belt issue but here's a list of symptoms I've experienced recently:
- Droning, loud idle;
- Smelly idle (smells like it's running rich);
- Bad droning, lumpy running at low revs (for example 45 mph in 5th gear);
- Pronounced "clutch chatter" (shuddering) when short-shifting (shifting up to a higher gear at low revs);
- Severe dip in revs and occasional stalling when lifting off suddenly when at low load/revs (for example, parking);
- Misfiring at partial throttle/low loads;
- Dyno: torque curve falls quickly to below 100 lb-ft near redline;
- Datalog: MAS input frequency plateaus and then falls off at higher revs;
- Datalog: noisy knock sensor output despite running with low boost/race gas;
- Datalog: inconsistent AFR and timing readings on back-to-back pulls; timing frequently being pulled by the ECU.

I've had many of these symptoms for quite a while so it's possible my timing has been broken this way for a long time now. Now that I think about it, it should have been obvious there was something wrong, but I attributed it to my car being a "cranky race car" what with the carbon-kevlar clutch, poly suspension bushings, stiff spring rates, big open exhaust and HFC. With the timing fixed, many of the above symptoms have entirely gone away and some are much less severe.

I've had a couple smelly-idle problems. The first time was actually due to the crankcase breather elbow popping off the engine (back of the valve cover passenger side). More recently, it started happening after my trip to the Gruppe-S dyno, during which I installed a Helix HFC. It went away after I did two things: painted the HFC and re-installed it, and changed the fuel pump from a high-pressure to a low-pressure Walboro 255lph.

I'm not sure which of these fixed it. It's possible that the new cat simply needed to be broken in (which I may have helped by curing the ceramic paint by baking the cat at 400F for a couple hours). It's possible there was an exhaust leak that simply went away after I reinstalled the cat. It's possible I had initially had the HFC mounted "backwards" (Helix name plate facing up) and then corrected the problem (I know I definitely turned the cat around; but is it directional?). You mention you're still on the stock cat though so a HFC can't be the problem. The problem did seem to go away even before I fixed the timing issue so it may not be timing-related.

[ace33joe]

Thank you for your kind reply! I guess my timing is not off yet. :) I did some pocket-logging, and I saw as low as 2 degree advancement at 5th gear near 3500rpm (of course WOT), but I guess that may not be due to the timing belt thing.

Anyhow, I guess you will get good aftermarket timing belt & balancer belt soon? I guess PE, Greddy, HKS are available. (I like the HKS purple color though. :) ) Thanks again for your detailed explanation.

[vtluu]

Yup, picked up Power Enterprise belts from WORKS yesterday, and Helix cam gears from Gruppe-S. Waiting for a new water pump to come in and I'll do the timing belt job then...

[vtluu]

So, I started the timing belt job last night. Got the lower cover off and found something surprising; here's the old photo (sorry didn't take a new one):

http://www.norcalevo.net/gallery/albums/album434/timing2.jpg

That hole right above the TDC mark, isn't supposed to be there. Inspecting the hole more closely, it looks like something smashed a 1.5" hole in my timing belt cover from the outside. The plastic is pretty sturdy so I'm not sure what could have done this; hard to imagine a rock could have gotten in there but it's possible. It's just a guess, but I think the same event that caused the hole is likely the one that caused my timing belt to skip a tooth.

[XVeloX]

ya i was wondering about that when i saw your pic there...

[KevOVIII]

I was also looking for the "T" mark. That picture didn't look similar to what I saw when I installed my cams but now I know why. lol

Glad you fixed your issues.