How To Adjust Timing in the FJ80 (1 Viewer)

[Iceaxe]

Ooohh... ok. For those of us who don't have access to a dyno / etc and are trying to do this at home, what do you recommend?

 

[scottryana]

I recommend setting timing to stock.
Getting brand new knock sensors (not cheap).
Use a code reader to clear any codes you might have.
Fill with the worst gas you will use
On a hot day
Do a 2nd - 3rd gear pull from low rpm's to redline while listening for any knock
Re-check codes to see if you have any knock codes I think they are like P0325 or P0330 If no codes advance timing 2 degrees
Do a 2nd - 3rd gear pull from low rpm's to redline while listening for any knock
Re-check codes to see if you have any knock codes I think they are like P0325 or P0330 If no codes advance timing 2 degrees
continue to do this until:
you experience any knock, then I would back timing back 3 degrees.

Then I would install your water/meth injection and use it only for charge cooling and not to increase timing.

 

[Iceaxe]

You rock man. THANK YOU for the guidance.

 

[Howard705]

When I do it and am setting up my tune on the dyno, we use knock ears and then dial back about 2 degrees across the entire range. A little different since I am using a stand alone and am in control of all the ignition timing. But I would treat it the same way. Start low, add timing until you have knock and then dial base timing back 2-3 degrees.

I recommend setting timing to stock.
Getting brand new knock sensors (not cheap).
Use a code reader to clear any codes you might have.
Fill with the worst gas you will use
On a hot day
Do a 2nd - 3rd gear pull from low rpm's to redline while listening for any knock
Re-check codes to see if you have any knock codes I think they are like P0325 or P0330 If no codes advance timing 2 degrees
Do a 2nd - 3rd gear pull from low rpm's to redline while listening for any knock
Re-check codes to see if you have any knock codes I think they are like P0325 or P0330 If no codes advance timing 2 degrees
When you experience any knock, I would back timing back 3 degrees.

Then I would install your water/meth injection and use it only for charge cooling and not to increase timing.

I believe that snap-on/otc type scan tools used to display when knock was being detected (knock retard?)- on GMs anyway-

 

[inkpot]

Just a little personal experience on timing a SC rig. I have had the rig for 5 years. Have run timing mostly at 3 degrees advanced, but have tried 5 also. Did not notice any performance change or. Any knocking. Tried 7 for a while when local temps were way over 100 every day. Occasionally could hear some rattle over 4000 rpm and kind of felt like timing was pulling back. Could not watch scan gauge to compare indicated timing. Performance seemed to be negatively affected on long highway hill climbs. Assuming timing was pulling back.

Seems to run out a little better with timing back @ stock 3 degrees. Weather has cooled off a bit, staying under 100, so may not be able to do a good comparison test for temp/ knock until next summer.

 

[TrickyT]

I thought it was the case with the FZJ80 that you set the "base" timing using the Te1-E1 jumper method and then the ECU would add additional spark advance when it wanted, but that it could not retard timing below the base level. So, even though the ECU may "know" what value you've set as the base level (and can report this via OBD II), your timing advance will never be less than this. The reason this is important is that the ECU may need to back off the additional advance it has added (by adding less) if it senses knock occurring, which of course are what the knock sensors are for. If you set the base timing very high (like Qball did) then the ECU may not be able to retard the timing enough when it needs to. Also, listening for knock may have worked fine in the old days before timing was controlled by the ECU, but I'll bet that knock sensors are better than your hearing now a days. In other words, you rarely hear knocking because the ECU has already sensed it and retarded the timing accordingly.

Edit: Revised sentence #2 based on later posts below.

 

[NLXTACY]

^exactly

 

[inkpot]

I guarantee you that when I set the base timing @ 7 degrees the ECU was still more than able to pull timing down to at least 4 degrees according to my Scangauge.

 

[TrickyT]

I guarantee you that when I set the base timing @ 7 degrees the ECU was still more than able to pull timing down to at least 4 degrees according to my Scangauge.

Unless you measure the absolute timing advance with a timing light, you don't know if the number the scangauge is reporting is relative to the "base" timing or is the total timing advance. In other words, "pulling down to 4 degrees" may in reality be 7 + 4, or 11 degrees total. Since a timing light is triggered off the #1 spark plug it's the only way to tell for sure what the total advance is. When I have some time and a buddy to help I can check this out and confirm if the scangauge reports total or relative timing.

 

[inkpot]

Unless you measure the absolute timing advance with a timing light, you don't know if the number the scangauge is reporting is relative to the "base" timing or is the total timing advance. In other words, "pulling down to 4 degrees" may in reality be 7 + 4, or 11 degrees total. Since a timing light is triggered off the #1 spark plug it's the only way to tell for sure what the total advance is. When I have some time and a buddy to help I can check this out and confirm if the scangauge reports total or relative timing.

So that begs the more basic question that may of been discussed before but I can't find. When you set timing at 3 degrees using the jumper in the diagnostic socket it does NOT show 3 degrees on the scan gauge. It stays at 4 both before and after removing the jumper lead. So, does that mean that the CPU always corrects/adjusts base timing to 4, or does mean that the CPU adds the amount indicated on the Scangauge to the base timing of 3 degrees?

 

[TrickyT]

I think that's the same question posed a different way. And to answer you need to know what the timing light shows after you remove the Te1-E1 jumper. If it jumps to 7 (=3+4) then the ECU adds the amount indicated on the scanguage to the base timing you set mechanically by adjusting the distributor rotation.

Edit: Note that I'm assuming the purpose of the jumper is to keep the ECU from adding or subtracting anything to the timing algorithm. Also, note in the FSM (page EG-15 in my 1997 version) it says:

5. (e) Remove the SST (i.e., the jumper) from DLC1.

6. FURTHER CHECK IGNITION TIMING
Ignition timing: 2-13* BTDC @ idle
(Transmission in neutral position and A/C off)
Hint: The timing mark moves in a range between 2* and 13*

7. DISCONNECT TIMING LIGHT

...so it's clear that the ECU is adding to the base timing in normal operation, although the question remains if what the scanguage is reporting is how much it adds. You need to watch the scanguage and the timing light at the same time to know for sure.

 

[inkpot]

Scan gauge and timing light do not really change when jumper is removed. The timing light setting appears to be more steady without jumper and scan gauge seems to be unaffected by removal.

 

[TrickyT]

OK, so what's the scanguage report when the jumper is installed and you set the distributor timing to 7* instead of 3*? Does it still report 4*?

 

[Qball]

Wow this thread is still going so let me chime in on my experiment in a bit more details.


As many already know I have a blown HG which I "fixed" with bar's HG fix. That's part of the reason I am willing to be that idiot who don't care about my engine and advance my timing from what some described as "ridiculous timing" to "ludicrous timing"!

First of all if you going to mess with timing get NLETACY's Wits' End glorified paper clip! I was using the regular paper clip which slipped and contacted B+ right next to Te1.....fortunately it only blew a fuse but gave me hella of a scare! And you obviously will need is a timing light, any timing light!


My setup:
97 LX (OBD2)
Land tank MAF mod(some say more accurate reading and breath better)
New denso O2 sensors
Dorkel(cooler intake)

Here my timing experiments in chronological order:

8 degrees and regular fuel: NO issues at all except when I went to get it pass smog I forgot I need to change it back.

6-7 degrees and regular fuel: NO issues

10 degrees and premium fuel(ridiculous timing): One day I got bored and changed it to 10 degrees, did not notice any issues or ping but used premium or 91 fuel just in case.

12-13 degrees(ludicrous timing) with premium/91 CA fuel: again I was bored and decided to try over 10 degree timing. With premium fuel I did not hear ping. NLXTACY did not believe me (and think I'm an idiot for going pass 10) so I drove over, picked him up and headed for the nearest hill for ping test. 85 degree day, 600lbs of extra weight, 10-15% grade and WOT.....Joey could not hear ping either to his disbelieve.



So.....I'm still running about 11-12 degree of base timing with 91 fuel with no issues and she drives great. Only issue was my stupid paper clip incident. I've been running advanced timing for well over 10k miles and still no issues and still have not heard ping once.

 

[NLXTACY]

For the record, I said over and over again, just because "I" don't hear it pinging it doesn't mean the knock sensors haven't been beating down the door to the ECU screaming "retard, retard, retard....retard is driving!"

 

[Qball]

For the record, I said over and over again, just because "I" don't hear it pinging it doesn't mean the knock sensors haven't been beating down the door to the ECU screaming "retard, retard, retard....retard is driving!"

Could be........BUT I did retard my timing back to 7-8 and watched my scan gauge. The base timing and timing at different throttle position hasn't really changed between different timing advance. My logic is that if knock sensors kicks off I should see my timing from scan gage go down and maybe even down to 0.

 

[LFD2037]

I think it's impossible for the ECU to retard below base timing. When I have the paper clip in, my Scangauge reads what the timing light reads.

 

[TrickyT]

I think it's impossible for the ECU to retard below base timing. When I have the paper clip in, my Scangauge reads what the timing light reads.

This makes sense to me. I've gone back and edited post #46 accordingly.

 

[NLXTACY]

I think it's impossible for the ECU to retard below base timing. When I have the paper clip in, my Scangauge reads what the timing light reads.

Thats been my understanding as well. Base is base. You are setting what the base is.

 

[Howard705]

Base is where the ecm times from. It still does what centrifugal and vacuum did probably advancing at least 35* depending on load and rpm THEN retards from that condition when it feels knock.