Thread: Timing Woes

Hey,

I'm trying to set my timing in my car and I've having some issues.

A few things first. I had to replace the crank pulley w/my lowport one on my highport(W10), does that cause any issues? If not, then on to my next problem.

The only way I get the car to 15* is to push the distributor basically all the way to the firewall. When I disconnect the TPS with or without reving past 3k RPM 3 times, it always shows the same timing marks. At 15* the car runs really bad. It runs like it's way too rich and runs extremely slow. Almost like the timing is at 3* or something(since distributor is all the way towards firewall this makes sense), but the timing says 15* when I get it in timing mode.

If I set the distributor in the middle, the timing looks like it's set at 22*, but the car runs better.

Anyone have any ideas what's going on? Anything I should check? I tried both timing methods - the Kojima method & the FSM method. They both show the same thing.

Thanks,
-G

So did you actually do the timing dance to get the car in timing mode or are you just turning the dizzy

Sounds like you have a bad pulley separted. If it is in timing mode.

Yes, I did the FSM dance. I also tried the Kojima method where you just get it warmed up, unplug the TPS and rev past 3k RPM 3 times. Both with the same result. The odd thing was if I just unplugged the the TPS, the timing marks showed the same before/after reving it. I wasn't sure if you can actually see the timing marks change position after the 3 revs or not.



I was reading the FSM and supposedly when the engine is turned to TDC, the pin should be on 0* on the crank pulley. I think that's one way I can tell if the pulley is installed correctly. When I swapped the pulleys, I never set it to 0*, I just put it on there.

I'm getting a consult cable soon. I'm thinking I can use that to check my timing if the crank pulley is all messed up.

That's okay. There is only one way to put it on.

You should check for TDC though and make sure the pulley corresponds.

Ben is right - there is only one way to put the pulley on because a notch and key locates it on the crankshaft. Both of the SR20 pulleys should be usable here, although there is some variation in early years with marks at 17* and stuff. Basically, when you are looking down with a timing light over the passenger side fender, the mark on the far right is 20*BTDC and then the others are at 5* increments (e.g. the second from the right is 15*) unless there is an obvious spacing anomaly which would indicate the 17* mark.

Aftermarket pulleys are all over the map when it comes to timing marks, so I hope that you are working with a factory pulley.

When you put the engine in set timing mode, the timing doesn't generally make a big shift in value that you would see. It just locks in at the base timing setting (determined by distributor location) rather than jumping around a bit. In normal idle mode, the ECU adjusts the timing to maintain a steady idle and that's why you see it jumping around and it's hard to set it accurately.

As you suspect, it's not normal for the distributor pushed all the way toward the firewall to read 15*. As blackb13se-r mentioned, sometimes the inside of the pulley can separate from the outside so the timing marks get out of synch with the key that locates the pulley on the crankshaft. This causes the kind of thing that you are seeing. The only other cause of this symptom that I know is if the exhaust cam is out of timing with the crank due to a screwed up cam install or, much less likely, the cam sprocket jumped a tooth on the chain. I doubt that you have this because you did not mention a cam swap, and the engine seems to run well with the distributor near the center of the range in the bracket.

So, you can try to check to see if the pointer is at 0* when the engine is at TDC by tracking the movement of the #1 cylinder with a long dowel or screw driver through the plug hole. Given that you are looking for an error bigger than 5* you will probably see it if it's there. Then you will know that you should try another pulley. Remember, the cylinder will come to the top of it's stroke twice for each full rotation of the pulley, so the timing marks will be 180* off at one of these times.

Don't count on Datascan to help you out much here. It's great for a lot of things and reliably puts the engine in set timing mode, but it doesn't know how to read the actual base ignition timing of the engine which is determined by the physical location of the distributor. Datascan ALWAYS assumes that the base timing is set at 15* and works from there.

Good luck working through this.

Billc

Have you had the cams out or have you done anything that could have caused you to jump a tooth on the exhaust cam? I would check that next if you find that your crank pulley is good to go.

The way you are describing the problem does sound like the pulley separated though, cause in the middle it should be around 15*, then all the way toward the firewall should be high like 22* not the other way around like you were describing.

What do you mean by separated? That it is coming apart from the engine? Would that just requre tightening or do you mean it's come out of the lock holes? Either case, if that's true it doesn't sound very safe. I have noticed when I start the car in the morning I hear a belt slipping on start up. Just a quick slip sound and then it's gone. Not sure if that has anything to do w/it.

Cams have not been messed w/as far as I know. I got the engine from an importer. I do plan on changing to S4 cams next weekend, so we can check out the position of the timing chain and such.

Ya, basically, in the middle of the distributor it's about 22* and then almost all the way to the firewall it's around 15*. Then almost all the way towards the front the car it looks like it's at something like 35* timing. It's off the charts. When I put the TPS back in, the timing goes to about 5* at idle. Something else, when I get the car into timing mode, the car idles at about 1500rpm w/the idle screw turned all the way down. I recently cleaned my TB, which bumped my idle up about 400rpm. But when I get out of timing mode, the car idles at about 1000 rpm.

The OEM crank pulley has rubber molded between the inner and outer
part of the pulley to absorb vibration. If the rubber fails, the
inner and outer pieces can move independently, causing the timing
marks to be out of alignment with the key on the crankshaft.

Here are some pictures to help with the mechanical timing, although
this is with an Unorthodox Racing pulley:
http://www.sr20-forum.com/general-sr20/24684-mechanical-timing-correct.html

How would I check if it separated? Is this common? What other issues would it cause?