Advanced timing

[malmon]

Hello guys! Got a question.

I have a '97 LX450 with about 90K miles. I went to a Test Only Smog Center yesterday and my emissions passed but the tester failed me on the test because according to him my timing was too advanced (18 BTDC).

My questions are: 1. What should the timing be to pass the CA smog test? 2. Isn't it the computer's job to take care of this timing? Is there anything wrong with my computer or some of my electronics? If so, which part is wrong and how do I correct this? Is there a DIY thread on this?

I've searched the forum and I can't seem to find a thread on this.

I tried turning the distributor but in the absence of a timing light, I couldn't say exactly what the setting is but there is still this "ticking" sound typical of an advance setting.

Any ideas?

Thank you so much for your help.

 

[alkaline747trio]

Here's what to do, with ign. off, open the scan tool lid (I think OBDII still has one) and run a paperclip between E1 and TE1, loosen bolt to adjust distro, start engine, let idle until rpms are steady and take note of idle rpms, turn distro in whichever direction that makes the RPMs drop, adjust it untill your idle is about 150-200rpms lower than it was at when you started engine, turn off engine, remove paperclip, restart engine and listen for spark knock (ticking), if none present, apply emergency brake, hold foot on brake, and push gas pedal as far as you can without moving the vehicle and listen for spark knock, if none then you should be in factory range, if spark knock is present, adjust distro to a more retarded setting after shorting E1 and TE1 again.

 

[malmon]

Thanks a lot Alkaline... you've been a great help )

 

[IdahoDoug]

I would not recommend timing by ear like that unless you have a lot of experience in tuning engines. Which pretty much means you would not be asking a question like this.

Buy an engine timing light and use the procedure on the sticker under your hood to properly set the timing. If you've been randomly moving your distributor around already, then you have no idea what the base timing currently is. Great way to destroy an engine.

Also, you need some clarification on that "18 degrees of advance" someone at the test place told you. Doesn't sound right unless they put it in some type of test mode with their gear.

DougM

 

[alkaline747trio]

Doug is right, having experience makes the way I told you more effective, but is the propper way to do it if you don't have a timing light. I would suggest having someone with some engine knowledge and a timing light help you, or take it to a trusted shop and tell them what you would like done (mention how to short E1 and TE1 for base timing when you do). I believe 7* is factory base, computer advance should be around 12-14*, but I could be wrong.

 

[malmon]

Yes, you are right. I have little knowledge of the timing in the LX450. I plan to bring it to the shop tomorrow but today, my wife used the car. What kind of damage will happen to the engine if say she drives it for about 150 miles today?

 

[alkaline747trio]

Did you try adjusting the timing the way I mentioned yet? Running it to advanced can foul plugs and damage valves, but these engines can take this for quite some time without damage. Tell the shop to get you the most advance without spark knock. 18* isn't really that high, and running a high advance shouldn't be an issue unless you are pinging, but definatly shouldn't fail you in a smog test.

 

[malmon]

Not yet. It was already late last night and of course you know that Monday mornings are hectic ). I was thinking of doing it tonight if I can get home early or just take the time off tomorrow morning and bring it to the shop.

 

[alkaline747trio]

Did the smog shop run a timing light or scan tool to find this 18* reading, or what? Also, did they say this was legally too far advanced, or were they more concerned over the pinging.

 

[malmon]

The smog tester run a timing light and said that 18 BTDC is too high to be legally allowed. Do not know the rationale for giving this. He didn't even tell me what the upper limit is. They were not really concerned about the pinging since it's not there ordinarily. It will only appear when the car is stressed like when it's going up a grade say in the mountains. We live in an area where we have to pass through some hills.

 

[alkaline747trio]

Ok, a limit on timing is BS, and don't fiddle with your's to adjust for that, ask the shop to adjust your base timing as high as they can without pinging. I know pretty dang sure that 18* couldn't be legally too high, a Corvette runs factory 22* unless I'm mistaken.

 

[IdahoDoug]

I think 7 degrees base timing is a reasonable advance from the factory 3-4 degrees. A Vette engine is not only a completely different engine (!), but an engine built to run at whatever the factory spec is. This engine sounds like it ALREADY has too much advance, so it needs the attention of a timing light. The instructions for your mechanic are on a sticker on the bottom of the hood near the front.

DougM

 

[malmon]

Thanks again guys. I'll probably just go to Sears later to get a Timing light.

 

[alkaline747trio]

Doug, I'm under the impression that 1) the smog guys are retarded/bs'ng malmon and 2) the timing has been messed with before.

Taking it to a shop to have the base timing adjusted between 3-7* and checked for pinging will put him in a safe zone, and the smog police need not mess with his timing as a more advanced setting is normally better for the environment due to the more efficient burn.

The reason I brought up the vette engine was to shed light on the smog guys throwing him a big pile of bs. I know it is designed to run at factory specs, but then again so is the 1FZE, and with computer controlled advance/retard it seems as if the ECU on his rig doesn't feel the need to reduce it below 18*, but it wouldn't hurt to retard the base to get it closer to specs if it is out of range.

 

[malmon]

Finally solved the problem.

As planned, bought a timing light from Sears last night and worked on it this morning. Took me under five minutes to set the timing to factory settings. Went back to the Testing site and got my Emissions certificate.

Now I have a timing light that has been used for less than five minutes. The cords have not been unwrapped yet. eBay here I come )

 

[alkaline747trio]

What was your final timing set to? Not base, but after you un-shorted the connection.

 

[malmon]

What was your final timing set to? Not base, but after you un-shorted the connection.

I set it to 3 BTDC. Thanks for all the help!

 

[alkaline747trio]

Set the base to that, do you know what the computer advanced it to?

 

[malmon]

After setting it to 3BTDC, I drove around and checked it again before I went to the Testing Center. The timing at that point was hovering between 3*-4*. Is that typical? Did I answer your question? )

 

[IdahoDoug]

I think he's curious what the computer runs it at with the jumper off. I am also, because the 18 degrees they claimed seems strange.

DougM