Cannot set Base Timing to 10*
 

Hi all,

I've just wrapped up my swap/turbo build and am inching closer to driving my car for the first time in months but am running into some real trouble getting the base timing set.

The car is a 90, with a 94 1.8 motor, running a Rev. built MS3. To my knowledge I've followed his specific instructions to T and have gotten the car to idle roughly but the best I can get the crank marks to read ends up being about 22* btdc.

I've turned the CAS end to end (this shows a great difference but ultimately I run out of room at 22* with it turned all the way to the top)

Ignition timing in Tuner Studio is set to fixed value:10*
I've used the ignition timing wizard to make adjustments as well. It seems to be closest at 20* in the timing wizard (it still only gets to ~22* at best and really just doesnt move from there if the CAS is in the right position)

I've looked into damper separation and dont really think thats whats happening. I can put cyl. 1 at tdc and all my timing marks line up correctly, including the crank.

If anyone has any theories or suggestions I'd be welcome to them. Im really not sure how many other ways to adjust timing there could be.

So close but so far...

Check your timing belt alignment.

Yeap, a tooth off could cause this along with a bad idle.

Also check you don't have one of those adjustable timing light guns.

Tore it down and set the timing again in the same fashion I did the first time. Same results.



https://www.miataturbo.net/attachmen...ine=1442787453



https://www.miataturbo.net/attachmen...ine=1442787453


https://www.miataturbo.net/attachmen...ine=1442787453

Tried with two different timing lights as well. No difference.

One of the things I noticed while I was putting it back together is that even though I'm damn sure the crank notch is set correctly, when I got the timing cover back on, then lined up the cam marks again the marks on the pully didn't line up correctly and would read ~-5 and +5. (This was best case with me turning the crank just enough to take the natural slack out of the drivers side of the belt) I imagine they're intended to read -10 and 0.

I took the covers off to re check a few more times before I put it back together, in the end nothing else seemed like it would be correct.

The best result are when I rotate the CAS all the way clock wise and it seems like if I could get another 1/8th of a full turn it would be correct.

Slipped damper? Timing off on the exhaust cam by a tooth? I'm really not sure.

Given the age of the engine, a slipped pulley is not at all improbable. The pulley on my '90 engine was out by quite a bit.

It's easy to (temporarily) rectify.

Using a wrench on the crank bolt, turn the engine clockwise to nearly TDC. Removing all the plugs makes this easier. Clean the crank pulley in the area around the "0" mark with brake cleaner or similar.

Pull the #1 spark plug (if it's not out already) and drop a dowel down the hole. You can use a drift punch, a wooden dowel, a pencil (unsharpened), a socket-wrench extension, or whatever you have available. Just be sure it's not so short it'll fall all the way into the hole.

Now, rock the engine back and forth to locate TDC. It's easiest if you have a dial indicator, but you can do it by sight / feel as well. You'll find that there's a narrow dead-spot at TDC where no movement is observable. Find the center of that spot, and mark it with a paint pen (available at hobby / craft and art supply stores.)

Right, then just treat the new mark(s) as the true timing and carry on from there? The thought crossed my mind. Super Miata damper here I come.

Well there we have it...

https://www.miataturbo.net/attachmen...ine=1442790035

Only problem is, discovering this only made my problem worse. The marks are now even further off.

What the hell am I missing?

The only other thing that seems to be put of whack in Tuner Studio is my TPS. I think I have some wires backwards right now. That shouldn't have anything to do with it though, right?

I assume that means Joe Perez was correct about your pulley slipping? Have you replaced it?

He's temporarily fixed it with paint, but if I interpret his reply correctly, he's found that he still can't get the base ignition timing anywhere near 10° BTDC, and that "fixing" the pulley revealed the situation to, in fact, be even worse than originally thought.

(Which makes sense- crank pulleys tend to slip in the direction of indicated retard.)

I just have no idea what's causing the actual ignition timing problem, assuming the cam timing is correct. (We haven't seen a picture of the cams with the belt actually installed, after a few CW revolutions of the crank.)



EDIT: having looked again at your paint-marked pulley, something seems odd to me. Like it's slipped in the wrong direction.

I have not. I measured and took a best guess at 0 and re marked it. I'll likely be ordering a super damper but I don't believe that to be my real issue based on my findings after remarking the pully.

That paint on the cam gears is some what misleading, its marking a valley instead of a tooth and is incorrect. On both of the gears you can see the factory notch markings if you look closely and if you follow the tooth back its alot more obvious where the timing lies.

I just pulled the trigger on Emilio's Super Damper. I'll likely tear it down again this weekend to install it and recheck. If there are no other ways of setting/adjusting timing through my MS, or CAS than I can't help but feel like the problem is rooted in the mechanical timing. The pully situation certainly isn't helping though.

I reversed coil plugs once, and had the timing light reading off 2 or 3. Somehow it ran and idled, but it was seriously knackered and I couldn't get it to time with the trigger wizard or rotating the cas.

Putting the coils back in the proper order helped immensely.

This has been on my mind alot actually. When I first tried to start it I had my coil/plug order as 4-1-2-3 left to right from the front of the car. (Coil is a 1.6 that I switched the signal wires on.) With the plug wires in this order, the car would not start. I changed the plug order to 2-3-1-4 and the car started but I now have this timing issue. From what I understand, so long as the 1-4 wires and the 2-3 wires are on their own Coil bank the order doesn't matter.

Am I wrong on this?

No, that should be right.

It's running wasted spark though, so it'll be sparking at the top of the exhaust stroke, which might be the power stroke if things are out of order. If the 1st spark driver is trying to fire 2/3 instead of 1/4 I could see it still running while giving strange ignition values.

I honestly had no idea what I did, but I know it looked as though my timing was advanced a good 20-40 degrees and it didn't respond incrementally with the trigger wizard or cas turning, so I knew it was seriously messed up.

Might be worth checking, swapping and trying..

What makes you think it's not going to keep slipping, rendering your new marks obsolete? :dunno:

Because the ECU reads the angle of the CAS. It doesn't have the tools to interpret paint marks.

Probably only slips at high rpm or high accessory loads.

I had a revelation today...

This is how I had my CAS installed. You can see the bolt/channeled side bolted to the right side of the CAS. It fit perfectly and could be adjusted perfectly.
https://www.miataturbo.net/attachmen...ine=1443068469

I stumbled across a thread in which someone else couldn't get the car to start at all because their CAS was ultimately backwards. I came home and sure enough, there is a bolt hole on the left side of the CAS as well, and it also fits the channel perfectly.

This is after I reinstalled the CAS in the new direction:

https://www.miataturbo.net/attachmen...ine=1443068469

I didn't have much time to try starting it today. It did not want to start at all in the new position with the current plug wire configuration so I figured I would try re arranging the plug wire order.

Which CAS position is correct? (I believe the locking bolt goes on the left and the plug goes up). Can anyone with a 1.8 swap just verify their CAS position and plug wire order for me?

As for the crank pully/harmonic balancer, I certainly imagine if its slipped earlier in its life, it will slip again in the future. Like I said, I ordered a Super Miata pully so I should be chucking the oem unit in the garbage this weekend.

Pretty sure the plug should be at the top. I didn't realise you could even mount it flipped over like that. I've done a 1.8 swap and that's how mine sits and I could set the timing to 10 degrees.
https://www.miataturbo.net/attachmen...ine=1443068953