94 5SFE Valve Timing and Ignition Timing

[auto777]

I replaced a timing belt and a leaking water pump on my 94 Toyota Camry. I actually ended up installing three water pumps over the period of a few months, an autozone and a pep boys both of which leaked from various places, followed by an OEM with the pump housing which went in and worked perfectly.

After installing the timing belt with the OEM water pump this week, I rotated the crank pulley twice and verified the crank and cam pulleys were both at TDC. I then started the engine to make sure everything was ok before reinstalling the upper timer cover and closing it up.

When I test drove the car, the engine felt slugish and after doing some testing I found the ignition timing was retarted several degrees even though I had set it to 10 deg BTDC a few months ago). When I tried to set the timing, I had to rotate the distributor as far as I could to get it close to 10 deg (may be 7.5 to be exact). I cannot rotate the distributor far enough to get it to 10 BTDC.

My first thought was the timing belt must be off by a tooth, but I verified before closing up the engine that both crank and cam pulleys were aligned at TDC. I didn't think it was even possble to start an engine if the pulleys were off by a tooth.

Anyone have any ideas on what could be wrong. Could some other component be responsible for this if is the timing belt off?

[BMR]

Originally Posted by auto777

When I test drove the car, the engine felt slugish and after doing some testing I found the ignition timing was retarted several degrees even though I had set it to 10 deg BTDC a few months ago). When I tried to set the timing, I had to rotate the distributor as far as I could to get it close to 10 deg (may be 7.5 to be exact). I cannot rotate the distributor far enough to get it to 10 BTDC.

My first thought was the timing belt must be off by a tooth, but I verified before closing up the engine that both crank and cam pulleys were aligned at TDC. I didn't think it was even possble to start an engine if the pulleys were off by a tooth.

They'll run if off by a single tooth. But they'll be way down on power. I betcha the belt slipped a tooth. The tensioning pulley on the 4 banger is tricky to get properly tightened.

[93celicaconv]

Originally Posted by BMR

They'll run if off by a single tooth. But they'll be way down on power. I betcha the belt slipped a tooth. The tensioning pulley on the 4 banger is tricky to get properly tightened.

+1^ - engine might even run if off by 2 teeth, but poorly. 5S-FE cam timing is difficult, given the tilt of the engine and being able to see the proper timing orientation for the cam timing sprocket, especially in a Celica. A mirror works, but still getting this right isn't easy.

I learned a trick for this engine, that is good for all engines, when it comes to timing belts. If you mark the cam & crank timing pulley's and old belt with a paint pen before taking the timing belt off, you can count the number of teeth on the old belt on the tension side, then go mark the new belt in both spots by counting the same number of teeth. Then slip the new belt on the same marks on the cam & crank pullies - you will always be good without having to guess again.

[auto777]

A couple of other notes on this.

When I opened it up, the duralast timing belt was a little loose. May be a better way to put it is that it wasn't snug. I assumed the belt stretched since I was very careful to torque the idler pulley and make sure the timing belt was tight last time.

Also, I just remembered that I replaced a distributor seal on it a few months ago. That's when I last set the ignition timing. I'm just wondering if the distributor could be off by a tooth and needs to be reinstalled.

The car always ran rough at idle, never solved that problem even with tuneups. The pickup is back after advancing the timing. But its not set to what it should be due to the distributor limit.

Originally Posted by auto777

I replaced a timing belt and a leaking water pump on my 94 Toyota Camry. I actually ended up installing three water pumps over the period of a few months, an autozone and a pep boys both of which leaked from various places, followed by an OEM with the pump housing which went in and worked perfectly.

After installing the timing belt with the OEM water pump this week, I rotated the crank pulley twice and verified the crank and cam pulleys were both at TDC. I then started the engine to make sure everything was ok before reinstalling the upper timer cover and closing it up.

When I test drove the car, the engine felt slugish and after doing some testing I found the ignition timing was retarted several degrees even though I had set it to 10 deg BTDC a few months ago). When I tried to set the timing, I had to rotate the distributor as far as I could to get it close to 10 deg (may be 7.5 to be exact). I cannot rotate the distributor far enough to get it to 10 BTDC.

My first thought was the timing belt must be off by a tooth, but I verified before closing up the engine that both crank and cam pulleys were aligned at TDC. I didn't think it was even possble to start an engine if the pulleys were off by a tooth.

Anyone have any ideas on what could be wrong. Could some other component be responsible for this if is the timing belt off?

[bolink654]

They'll definitely start if 2 teeth off. I've done it, and ran a tank of gas through it before I had time to check/re set it.

[auto777]

Power seems to be back after advancing the timing to 7.5 BTDC. I'm certain I checked and recheck the torque on the idler pulley and belt was tight before buttoning it back up.

Originally Posted by BMR

They'll run if off by a single tooth. But they'll be way down on power. I betcha the belt slipped a tooth. The tensioning pulley on the 4 banger is tricky to get properly tightened.

[auto777]

My trick on this car (after reinstalling timing belet three times) is set cam to TDC, crank to about 10 btdc, install belt over cam gear, release tensioner, rotate crank 720 deg to verify both crank and cam are set to TDC, tighten tensioner.

Sounds like everyone agrees it can run if off a tooth. Only thing bothering me is checked it after turning the crank and both were at TDC...

Originally Posted by 93celicaconv

+1^ - engine might even run if off by 2 teeth, but poorly. 5S-FE cam timing is difficult, given the tilt of the engine and being able to see the proper timing orientation for the cam timing sprocket, especially in a Celica. A mirror works, but still getting this right isn't easy.

I learned a trick for this engine, that is good for all engines, when it comes to timing belts. If you mark the cam & crank timing pulley's and old belt with a paint pen before taking the timing belt off, you can count the number of teeth on the old belt on the tension side, then go mark the new belt in both spots by counting the same number of teeth. Then slip the new belt on the same marks on the cam & crank pullies - you will always be good without having to guess again.

[93celicaconv]

Originally Posted by auto777

I'm just wondering if the distributor could be off by a tooth and needs to be reinstalled.

For reference, this is not possible, at least the distributor relative to a correctly timed camshaft.

But if the camshaft is off by a tooth or two, the distributor must be off by the same amount, and the limits of distributor adjustment will not get this all back. Even it there was sufficient distributor adjustment, the cam timing is very, very important to get right.

I don't know about your method of setting the crank ahead while the cam is on TDC. That doesn't make any sense to me. But if it works for you, great!