Timing issue

[dlb]

if you are getting vacuum at the outer advance port at idle like you mentioned earlier, that's definitely not right. the inner port with the bigger hole is the only one that is supposed to get vac at idle. you should actually be able to plug and unplug the outer advance port at idle with no change to the rpm or ignition timing.

[Mark]

I found out that Canadian Tire doesn't loan out timing lights and I wasn't going to spend $50-$100 for a new one just to check the accuracy on my old one. Just for the hell of it I checked the timing on my other car ('83 Tercel hatchback) with my old, suspicious timing light and it showed about 16 degrees BTDC. I decided to give up and set the timing manually on my 4wd wagon. I rotated the pulley to TDC and checked to make sure the rotor on the distributor was pointing at the #1 wire. I then made sure one of the "pointers" on the rotor was centered on the ignitor. Then I rotated the crankshaft pulley to the 10 degrees BTDC mark and rotated the distributor so the point on the rotor was again centered on the ignitor. From what I understand, this should mean my timing is now 10 degrees BTDC. I checked with my timing light and it showed 40 degrees BTDC. I wasn't falling for it this time so I took it for a test drive. There was great power (maybe even better than originally). I tried some hard acceleration (even though there are no decent hills in my neighborhood). I floored the accelerator and the acceleration was powerful, smooth and there was no knocking or power loss. I assume this means that my timing is not too far advanced. Until I can borrow another timing light to verify, I'm going to stick with where it's at now and try to forget about it for the weekend.

[celtglen]

I found out that Canadian Tire doesn't loan out timing lights and I wasn't going to spend $50-$100 for a new one just to check the accuracy on my old one. Just for the hell of it I checked the timing on my other car ('83 Tercel hatchback) with my old, suspicious timing light and it showed about 16 degrees BTDC. I decided to give up and set the timing manually on my 4wd wagon. I rotated the pulley to TDC and checked to make sure the rotor on the distributor was pointing at the #1 wire. I then made sure one of the "pointers" on the rotor was centered on the ignitor. Then I rotated the crankshaft pulley to the 10 degrees BTDC mark and rotated the distributor so the point on the rotor was again centered on the ignitor. From what I understand, this should mean my timing is now 10 degrees BTDC. I checked with my timing light and it showed 40 degrees BTDC. I wasn't falling for it this time so I took it for a test drive. There was great power (maybe even better than originally). I tried some hard acceleration (even though there are no decent hills in my neighborhood). I floored the accelerator and the acceleration was powerful, smooth and there was no knocking or power loss. I assume this means that my timing is not too far advanced. Until I can borrow another timing light to verify, I'm going to stick with where it's at now and try to forget about it for the weekend.

Is AutoZone in CA? or O'Reilly? They both loan INDUCTIVE timing lights..the kind you should use for these. You might want to check a couple of things inside of the timing belt cover..noteably the tensioner and the spring if either are in need of replacement then the belt will not behave properly.
CG

[Mark]

So I'm still somewhat confused. I just bought another second-hand timing light (inductive) today for a second opinion. It's still showing 40 degrees BTDC when no vacuum hoses are disconnected. So my old timing light was accurate. When the vacuum hoses are connected it's SUPPOSED to show about 15 degrees, but the car runs great and I'm surprised to be getting a consistent 30mpg around town (better than before although maybe it's the warmer weather). I just came back from a trip up the island to Nanaimo and back and I'm almost shocked to see that on the mostly-highway trip I got 38 mpg (with an automatic!). I just bumped the timing down to a bit over 30 degrees BTDC because I'm paranoid, but even on the steep sections of highway (high rpms) I was getting no pinging.
I changed the timing belt a few years ago (the old one didn't break, I just put a new one exactly where the old one was). Is it possible to put the crankshaft pulley on wrong? I assume the crankshaft end has a notch that would only allow the pulley to go on in a certain position, but I can't remember.
If the timing is actually 30-40 degrees before TDC, is it normal for the car to drive normally? Is there a timing advance where you would expect to hear pinging?

[dlb]

no, if the timing was actually at 30-40* BTDC you would be getting issues like pinging, backfiring, rough running, etc. it's tough to say where to expect pinging because several other things affect it, like compression and carbon buildup. i have found that a base timing of 10* BTDC is the highest advance i've been able to run in tercels, and even then it will ping a tiny bit when the revs are too low while taking a steep hill when the engine is hot.

no, installing the crank pulley is foolproof in that it has a groove that a woodruff key (the manual calls it a set key) locks into. this means that the pulley can only be aligned in the correct orientation to the crankshaft.

when you put the new timing belt on a few years ago, did you set the timing using a timing light?

[xirdneh]

if its not pinging
i'd say the "if it ain't broke don't fix it " rule applies

[Mark]

When I replaced the timing belt I didn't check with a timing light (I didn't have one then). I just marked the old belt (with a white paint marker) at one tooth on each pulley, removed it, lined it up with the new belt, marked the new belt in the same spots and installed the new belt exactly where the old one was. I now wish I checked the timing before I removed the distributor, just to see where it was at the whole time I owned it. I agree that I'm probably just going to leave it since it runs fine. By the way, there are 3 holes close together on the crankshaft pulley at about 3:00 (compared to the timing mark). What are these for? I couldn't find a reference to them in the FSM.

[Mark]

So retarding the timing this morning to "only" 30 degrees BTDC was a bad idea. There was no power and acceleration was weak. I advanced it back to 40 degrees, where it seems to be fine. I think I'll leave it there and try to stop worrying about the inexplicable.
By the way, is "pinging" noticeable when you're driving? I have all kinds of rattles in my dash and doors. I assume if the timing was too far advanced, the pinging would still be obvious over all the background noise?

[dlb]

pinging gets louder as it gets worse. with subtle pinging, you have to listen for it. if it's really bad, you will have no problem hearing it. i think you would recognize it because it really does sound like a bunch of pinging. it is not regular and does not occur faster or slower with revs.

btw, 38 mpg is outstanding, especially in an automatic! is that with the wagon or hatchback?

[Mark]

pinging gets louder as it gets worse. with subtle pinging, you have to listen for it. if it's really bad, you will have no problem hearing it. i think you would recognize it because it really does sound like a bunch of pinging. it is not regular and does not occur faster or slower with revs.

btw, 38 mpg is outstanding, especially in an automatic! is that with the wagon or hatchback?

That's with the 4wd wagon. I'm not going to claim that that's the consistent mileage since the fuel gauge is really just a "guess". It's probably not the best practice, but what I do is put in $20 of gas at a time and wait until the low fuel light comes on before adding another $20. This time when the low fuel light came on, I put in $20 in Duncan (that's the name of the town, not my car) at $1.34/liter. That gives me 14.93 liters. This lasted me 200 kilometers until the low fuel light came on again. I plugged the numbers in to the following online mpg conversion calculator: http://www.accommodationz.co.nz/economycalculator.html
It gave me a mpg of 37.86 mpg or 7.47 l/110 km. So far in the past couple of weeks I've been getting a consistent 30 mpg around town, including maybe 25% highway driving. Last fall and winter before I repaired the transmission, I was getting about 26-28 mpg in town and 30 mpg on the highway. The weather is warmer now, but I think the 40 degrees BTDC helped too. I think I'll write a letter to Toyota suggesting they make this "super-advanced" timing standard on all of their vehicles. Maybe for super-efficiency they could advance it even further so the spark is firing when the piston is at the bottom. This would probably drastically cut down on emissions.

[Petros]

check the position of the upper cam sprocket relative to the crank shaft using the alignment marks on the front of the head per the FSM. it is not difficult, just look at the position of the timing marks on the upper pulley with the timing cover off. that is the only way to know for sure what is going on. I doubt you are at 40 deg advance, are you puting the spark sensor clamp on the number one spark plug? It must be on the correct spark plug to know for sure. unless you have really low compression, than you can run 40 deg advance. But if that is the case you would not have good power nor good economy.

That is not a reliable way to check economy, the best is to record and gallons (or liters) in, and mileage each time you get fuel, and than average it. the other way is to fill it to the top each time. than you know exact miles and gallons used between fill ups. You are likely averaging about 30 mpg which is normal.

[Mark]

check the position of the upper cam sprocket relative to the crank shaft using the alignment marks on the front of the head per the FSM. it is not difficult, just look at the position of the timing marks on the upper pulley with the timing cover off. that is the only way to know for sure what is going on. I doubt you are at 40 deg advance, are you puting the spark sensor clamp on the number one spark plug? It must be on the correct spark plug to know for sure. unless you have really low compression, than you can run 40 deg advance. But if that is the case you would not have good power nor good economy.

One of the the first things I did when this issue started was to verify that the cam pulley mark was at TDC (The small triangle is lined up in the small hole in the pulley) when the crankshaft pulley was showing zero degrees on the lower cover. I'm putting the light's inductive clamp on the wire closest to the bumper that says "1" on it. I even checked the lower cover and compared it the one on my 2wd hatchback to see if the degree marks are in the same spot and they are.

[Petros]

well than it is a mystery. if it does not ping, and you are getting good economy, I would just leave it.

[rer233]

Mark- have you verified that the zero mark on the crankshaft pulley actually coincides with #1 piston being at TDC? The reason i ask is years ago, i had a 3ac engine crankshaft pulley that had the keyway completely whacked-out. Just a thought...

[dlb]

Mark- have you verified that the zero mark on the crankshaft pulley actually coincides with #1 piston being at TDC? The reason i ask is years ago, i had a 3ac engine crankshaft pulley that had the keyway completely whacked-out. Just a thought...

i just thought the same thing, rich. i recently learned that my honda civics had two marks painted on the crank pulley, one for TDC and one for 16* BTDC. problem was that the 16* BTDC mark was red and didn't show up when the timing light flashed so i was scratching my head for a little while over that.

and so i ask: mark, is the painted mark right on the small cutout notch of the pulley?