T/B fiasco-motor now fubar

[Ataim]

It hasn't left the driveway. He spent two days on it and then disappeared. Really a reliable upstanding guy.

Two days The second time I did one I changed the Waterpump, bearings and TB by myself in about 3 hours from opening the hood to closing it.

[Ataim]

Picture

[POS Racing]

I'm sure that someone has a picture that they can post on what it's supposed to look like.

Good stuff here - http://www.miata.net/garage/timingbelt.html

Hey Cam how did you find this expert??

[trickyrix]

Hey Cam how did you find this expert??

You didn't pick up one of these day laborers, did ya?

[cam76034]

Rub it in guys, I already beat myself up on this so much that there's nothing anybody can say that could bother me at this point. That long drive to Arkansas and back gives one plenty of time to think...and kick myself a few hundred times over.

I found him on dfwmiata when I bought some AC parts this summer. While talking miatas, I told him I had 2 that were due for TB change. He called me a few weeks ago and the rest is history. Unfortunately, I didn't know his.

[cam76034]

Once again, how can it run on 4, 1 and 2 but not on 3? After running for just a minute, you can smell the unburned gas.

I'm guessing it would not be wise to drive it that way ie: Gas diluting the oil?

[trickyrix]

I got nothin' on the #3 plug, but I wouldn't drive it like that. All that unburned fuel going out the exhaust can't be good for things like the cat.

[POS Racing]

Ya sure you got the plugs in the correct order?

[MadMerv]

The key to a proper timing belt replacement is the setting of the tensioner. If one doesn't follow the procedure (turning the crank 1 5/6 revolutions) the belt can easily jump a cog or two. It's simple to fix. Someone go help the poor guy...........

[cam76034]

Ya sure you got the plugs in the correct order?

Firing order double checked. If only it was that easy.

[sammm]

Bad plug wire? Did you try swapping #3 and #4 wires and see if the problem follows?

[cam76034]

Fairly new NGK wires with less than 5K on them, and the plug is firing.

Went ahead and removed the valve cover and upper TB cover. When at TDC, the E and I line up at approximately 12 o'clock, although the I isn't exactly at 12 o'clock. What really stands out is the amount of slop in the belt at that point between camshaft gears. It's supposed to be 3/8" but it is actually more like 3/4". Then, when rotating the crankshaft through a full cycle, it gets alternately really tight, then really sloppy again. It should be the same tension throughout shouldn't it?

However, there are 19 teeth between I and E as I recall reading on miata.net.

Guess I'll continue taking off the TB covers on down to where I can get at the tensioner and main crankshaft.

[POS Racing]

Have you talked to Rogue yet? What else did you expert replace?

[cam76034]

Well I just finished replacing the TB, made sure everything lined up. It still is missing on #3.

[sammm]

Try a different coil pack.

[channelmaniac]

Timing and spark are controlled by:

Timing belt alignment, plugs, wires, coil pack, and the CAS (cam angle sensor)...

Double check that the cas is plugged in all the way, the coil packs are plugged in all the way... make sure a plug wire didn't break... the plug isn't fouled out or electrodes touching (which can happen if the plug is dropped!)....

AND

Check to make sure the wiring at the back of the head wasn't pinched/cut/shorted by the valve cover.

[cam76034]

Possible, since the CAS wasn't disconnected while using the starter bump trick to break loose the crankshaft.

[cam76034]

Try a different coil pack.

I thought about that, but if I pull the plug and ground it on the valve cover, it's shooting a pretty good spark. I'm getting fuel, I've got spark, just no combustion in the chamber.

So I'm thinking ...
A: valve problem
B: injector issue?

Neither one of which I have much troubleshooting knowledge.

[TurboDuane]

Did he loosen the wires to the injector on #3? Heck, I'd check your torque on your harmonic balancer too. It would suck to have it fall off one day. Is the idler pully released and keeping the belt tight?

Also, boots on the wires sometimes trap excess air and I've seen them prevent a good connectoin to the coil, or cause a connector to pop off after a good connection was made.

[cone-cerned]

I thought about that, but if I pull the plug and ground it on the valve cover, it's shooting a pretty good spark...

If you are getting good spark at one atmosphere of pressure, does that mean that you will get a good spark at the pressure inside the cylinder? I don't know, I'm just curious.