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Ignition timing jumps to full advance


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Jawmighty
User

Dec 16, 2017, 10:35 AM

Post #1 of 26 (2076 views)
Ignition timing jumps to full advance Sign In

1986 toyota 4runner 22re. Full fresh rebuild, all parts under the hood replaced with new Denso parts, and I mean everything.
The ignition timing is at 5 degrees with the jumper in. With the engine warm slowly bring the RPMs up with a timing light on. At about 1600 RPMs the timing jumps to full advance. The RPMs instantly increase and it starts randomly miss firing when it hits 1600ish RPM.

EGR delete, header with 2.5 inch exhaust, GM three wire alternator and LCE torquer cam are the only non stock modifications.
I have multiple igniters no difference. I would really appreciate any help, thank you.


Hammer Time
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Dec 16, 2017, 10:48 AM

Post #2 of 26 (2071 views)
Re: Ignition timing jumps to full advance Sign In

How do you know it's not intentionally programmed to do that and the misfire is caused by something else?



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Jawmighty
User

Dec 16, 2017, 11:03 AM

Post #3 of 26 (2065 views)
Re: Ignition timing jumps to full advance Sign In

I took it to a shop and they said it was a problem but didn't know what was causing it, but I don't really trust them. Any help please...
I did this rebuild myself and have tried to learn all I can on the 22re, I have tested all I can per the Chilton and Haynes manuals.


(This post was edited by Jawmighty on Dec 16, 2017, 11:05 AM)


Hammer Time
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Dec 16, 2017, 11:31 AM

Post #4 of 26 (2061 views)
Re: Ignition timing jumps to full advance Sign In

You should be able to get flash codes. I would check that first.



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Tom Greenleaf
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Dec 16, 2017, 11:45 AM

Post #5 of 26 (2056 views)
Re: Ignition timing jumps to full advance Sign In

Quote from top ">EGR delete, header with 2.5 inch exhaust, GM three wire alternator and LCE torquer cam are the only non stock modifications.<" Fine I guess but what is the reading when you say FULL vacuum advance?
I'll never know nor could look it up but some meant to be backwards not advancing but retarding with a load so they don't knock still we call it an advance. There's manifold actual vacuum and air speed vacuum are two different spot on a carb to get which and temp sensitive when they all vacuum to pass. That just has to all be right for the exact engine or you may have it backwards. Just a thought may look the same and called the same but tons depends on where this carb/engine/vehicle as a whole was meant to be used new, California or Federal could be totally different or another destination might still have been able to use leaded gas and different again?
Any stickers with diagrams left this old? Also - under no load even at raised RPM you only get the speed sensing vacuum not if it were under load. Messing with this and deleting EGR was a mistake that may also be a problem - a vacuum nightmare for the ones I recall very particular that it's right,


T



Hammer Time
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Dec 16, 2017, 12:05 PM

Post #6 of 26 (2052 views)
Re: Ignition timing jumps to full advance Sign In

There is no vacuum advance Tom.



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Tom Greenleaf
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Dec 16, 2017, 12:21 PM

Post #7 of 26 (2047 views)
Re: Ignition timing jumps to full advance Sign In

OK - Maybe not on a distributor but it has to sense actual vacuum converted to an electrical impulse to do the same thing. If it thinks reading very high vacuum at a given RPM without load vacuum is way up there would advance so it doesn't run lousy then back off if lower.
With alterations not sure how to know if all is hooded up right or not and that's the problem. NO EGR? Oh my - it shouldn't be involved until part load or under medium vacuum again however sensed. It won't work when cold on about anything I know of or at WOT also but combo of throttle position and vacuum/load.


Where am I going wrong? The EGR delete worries me the most for the moment,


T



Hammer Time
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Dec 16, 2017, 12:29 PM

Post #8 of 26 (2041 views)
Re: Ignition timing jumps to full advance Sign In

No Tom, there is nothing reading vacuum and engine vacuum has no control of timing whatsoever.



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Jawmighty
User

Dec 16, 2017, 12:34 PM

Post #9 of 26 (2039 views)
Re: Ignition timing jumps to full advance Sign In

It flashes no codes.
Again I have tried my hardest to learn the 22re, and as far as I can tell the 86 toyota EFI system doesn't use vacuum. The distributor is a new OEM Toyota distributor from the stealership. Air gap is set per the books.


Tom Greenleaf
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Dec 16, 2017, 12:39 PM

Post #10 of 26 (2037 views)
Re: Ignition timing jumps to full advance Sign In

I'll stay out. IDK what else EFI or not tells what the load is on an engine other than "Manifold's Actual Vacuum" could just be a plug in thing to a wire - I'll never find that info specific to this. Fought with one for hours and that was it is all, T



Jawmighty
User

Dec 16, 2017, 1:10 PM

Post #11 of 26 (2029 views)
Re: Ignition timing jumps to full advance Sign In

Vacuum as I have tested shows between 12 and 15 measured off of the intake manifold at all RPM.

And EGR delete on this engine does not affect the timing in anyway, it is a primitive system that uses engine temperature to scavenge off a small portion of exhaust gas and sends it right into the intake manifold which can cause the intake manifold to get massive build up, the 22re runs better without it (not as environmentally friendly).


Hammer Time
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Dec 16, 2017, 1:38 PM

Post #12 of 26 (2027 views)
Re: Ignition timing jumps to full advance Sign In

The computer is not very helpful in this model so you may have to test sensors manually like TPS, ECT, MAF etc.

Does this happen under load?

Have you determined which cylinders are misfiring?

Have you checked the plugs for those particular cylinders?



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(This post was edited by Hammer Time on Dec 16, 2017, 1:38 PM)


Jawmighty
User

Dec 16, 2017, 2:16 PM

Post #13 of 26 (2021 views)
Re: Ignition timing jumps to full advance Sign In

I replaced all of the sensors and have tested the new ones with the Chilton and Haynes manuals. The TPS is correctly set, the AFM is a fresh Cardone remanufactured, and tests good.
As far as I can tell it doesn't doit under load but if you cruise at say 35 mph in third at 2500 ish rpm and take your foot off the gas pedal it dies but restarts just fine.


Hammer Time
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Dec 16, 2017, 2:19 PM

Post #14 of 26 (2019 views)
Re: Ignition timing jumps to full advance Sign In

Stalling at closed throttle is a whole lot different symptom than misfire as you stated first. Which is it?



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Tom Greenleaf
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Dec 16, 2017, 2:45 PM

Post #15 of 26 (2015 views)
Re: Ignition timing jumps to full advance Sign In

Said I stay out but see what can't be explained also a problem if correct? Quote back a few ">Vacuum as I have tested shows between 12 and 15 measured off of the intake manifold at all RPM.<"
Can't be right it would run for crap so another reason for that never mind timing anything. You do mean Hg? Tom


Jawmighty
User

Dec 16, 2017, 2:58 PM

Post #16 of 26 (2011 views)
Re: Ignition timing jumps to full advance Sign In

The miss fire only happens when the timing goes to full advance, at 1600 rpm. the stalling only happens after a sustained normal pull like holding 35 or 40 mph in third for like a mile or two.


Hammer Time
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Dec 16, 2017, 4:32 PM

Post #17 of 26 (2004 views)
Re: Ignition timing jumps to full advance Sign In

I think you should hook up a fuel pressure gauge and monitor the pressure during this episode.



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Jawmighty
User

Dec 16, 2017, 4:41 PM

Post #18 of 26 (2000 views)
Re: Ignition timing jumps to full advance Sign In

I shall give that a try again, it has a new pump regulator and pressure dampner. I tested them all at once after installation and 36 psi and 31 psi 24 hours later.

I am work until Monday but have a good internet connection here so I do most of my forum stuff while I am here.


Hammer Time
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Dec 16, 2017, 4:44 PM

Post #19 of 26 (1998 views)
Re: Ignition timing jumps to full advance Sign In

I specified to watch the pressure WHILE THE PROBLEM IS PRESENT. Checking it while it's idling smooth doesn't tell us anything.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Jawmighty
User

Dec 18, 2017, 12:35 PM

Post #20 of 26 (1956 views)
Re: Ignition timing jumps to full advance Sign In

Fuel pressure stays above 32 with it stalls.


Hammer Time
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Dec 18, 2017, 1:10 PM

Post #21 of 26 (1954 views)
Re: Ignition timing jumps to full advance Sign In

OK, we can eliminate that. Do you know how to monitor the 0/2 voltage while this happens?



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Jawmighty
User

Dec 18, 2017, 6:02 PM

Post #22 of 26 (1935 views)
Re: Ignition timing jumps to full advance Sign In

I will set that up and see what readings i get, The lambda sensor is currently between the header and the cat. I am not sure if it comes up to full temp, i do have a four wire heated one and have switched between the two with no noticeable difference, currently the one wire sensor is on it. Both units are new Denso.


Jawmighty
User

Dec 20, 2017, 5:10 PM

Post #23 of 26 (1918 views)
Re: Ignition timing jumps to full advance Sign In

When it stalls i am getting a reading of > 0.17
and am not seeing any higher than .89, under load. ( again it is a one wire sensor in 2.5 inch pipe 2 foot further back than stock, might not be getting hot enough )
Way rich from my understanding,
And the Timing jumping to full advance is noticeable on smooth flat take off.


Hammer Time
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Dec 20, 2017, 7:55 PM

Post #24 of 26 (1912 views)
Re: Ignition timing jumps to full advance Sign In

What was the 0/2 doing right before the stall?



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Jawmighty
User

Dec 20, 2017, 8:16 PM

Post #25 of 26 (1908 views)
Re: Ignition timing jumps to full advance Sign In

Going down in voltage






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