ignition timing wtf

[timbo]

Car - JDM ae86

motor -AE92 100kw smallport

use - daily atm

problem - ignition timing out, misfiring

occurs/started when - when i changed the dizzy o-ring


well i changed my dizzy o-ring and now i cant get the fucker back in time... i was so careful to mark everything but i turned it over and it misfires like a bitch. i have bridge T and E1 and set TDC 0" (crank and cam gears all line up) and the dizzy accordingly but i cant seem to find a happy medium, it is either too advanced or too retarded.

so any ideas? anyone in brisbane done this before? really could use a fresh set of eyes and thoughts.

the crank timing is as follows: 20 15 10 5 0 5. if its right of 0 it misfires and splutters and left it won't rev past 5000rpm.

[Skylar]

You are supposed to set it at 10. Read the manual.

[timbo]

You are supposed to set it at 10. Read the manual.

i understand that and have set it at 10 BTDC but i am still having problems. i used this as a reference:

http://www.toymods.net/TechDocs/4age_book/ignitionsystem/ig_11.jpg

[Skylar]

You are using a timing light right?

[timbo]

You are using a timing light right?

lol yes... i know it seems odd to still have a problem after following everything properly but i just can't work out what is going on.

[Skylar]

You're in the same boat as me then. We set ignition timing to 10 with check connector bridged. Car was so slow as all hell so we set it to what we thought felt about right which showed up as like 25 on the gun unbridged.

You have original crank pulley? I got some aftermarket thing. We suspect that's the reason it's being so goofball.

[timbo]

Yeah I'm pretty sure mine is original, and it is doing the same as yours, 20-25 unbridged. It's really starting to do my head in to be honest...

[slide86]

maybe you have put 2 leads on teh wrong way round or something like that......

it would explain the missfire and not revving

[timbo]

maybe you have put 2 leads on teh wrong way round or something like that......

it would explain the missfire and not revving

also a good thought, but they are on the exact way they came off. this does raise the question though, should the number one lead plug onto the dizzy where the number 1 is embossed?

[sundee]

i would pull the dizzy out and start again.. if u are even a tooth out where the dizzy gear meets the exhaust cam your screwed.

u should also notice - looking at the cam gears they should line up with the 2 markings on the rear cam covers. - 1 dot on each gear and risen line on the rear cover above each cam gear.

then re check the crank... and also check the valve position on cyl # 1 - all 4 valves should be closed

if all from the above diagram is good and what ive mentioned above is good.... the stuff i have no idea...

[slide86]

ah i had this exact problem not to long ago, and i think, it doesnt point exactly at it. (well with the cap that i had)

best way to do it is to line the engine up on number one TDC compression and then fit the dizzy, using the marks on the dizzy shaft then you dont have to worry.

im pretty sure no. 1 is bout '4 oclock' on the dizzy cap, if you get what i mean

[sundee]

just look inside the dizzy... the rotor button , when all ligned up with the markings on the dizzy shaft - will be pointing at the contact for cyl # 1...
so if thats your starting point - hook that lead to the 1st cyl ( #1).. go clockwise - next point to fire goes cyl # 3, 2nd from the back.. next point goes to cyl # 4 - most rearward - and last is to cyl # 2 - 2nd from the front.

[timbo]

thanks for all the input guys. started over again:

- lining up 0" TDC on the crank, then cam gear dots line up with the line marking on the rear covers
- insterted the dizzy with the dots lined up and leads 1 3 4 2
- turned it over wouldn't go unless the dizzy was turn as far as it could go anitclockwise
- still out of time

i am starting to think if the dizzy cap is the right one...

[sundee]

with the timing light on and the timing light hooked up to HT lead number 1, what is the timing set to?

the timing light needs to be hooked up to cyl # 1

[timbo]

10 BTDC but if you light up the cam gears they seem to be running 1 tooth behind even though they are spot on with the crank at TDC...

[sundee]

that would be right because the spark fires before TDC anyway

[timbo]

well thats good and i thought it makes sense but the timing is still off. i think it might be time to take it to a "professional"...

[ke70dave]

where you live mate? if your close i can offer assistance, been through your situation way to many times! im in wynnum 4178

[timbo]

where you live mate? if your close i can offer assistance, been through your situation way to many times! im in wynnum 4178

pm sent

[Marco]

still having issues with this dude? why didn't u give me a call? if you don't get it sorted i can come have a look tommorow.

[ke70dave]

pm replied. sounds like your just out a tooth on your dizzy mate

[timbo]

that was one of my first thoughts, so i tried what you just explained but its almost like im missing a gear in-between.

[slide86]

when you slide the dizzy in, it moves a tooth in one direction as it meshes onto the cam....i know that caught me out once on a 4age. i was aligning it perfectly but when i was installing it, it was moving on tooth out.

i didnt know this cause i was fitting it with the cap on.....but then i clicked and it was all sweet

[timbo]

ill have another crack in the morning, it could well be the dizzy missing a gear with my big gumby hands, i just hope i can sort it out before i lose my mind.

i'd like to thank everyone for their input, this is what makes ae86dc a great club and forum.

[Skylar]

We tried skipping a tooth one way but to get timing in range (by that I mean JUST reading on the edge of the 25 20, etc) it had to be set to full adjustment on the distributor mount.

I dunno, mine might be a tooth out but I didn't want it idling for too long as I needed to go run the engine in. I should probably give it another go soon.

[ke70dave]

just remember that there is only 12 teeth on the dizzy, so when its out by ONLY 1 tooth, your actually throwing your ignition out by 30 degrees.

actually that might actually be 60 degrees since there is a 2:1 ratio between the crank pulley and the cam pulley's....someone else can do the maths!

either way its a fair bit.

[timbo]

well fellas, im afraid to say that i took it to a shop just around the corner this morning. after about 4 hours a got a call from one of the mechanics informing me that he could not get the car to run any better than i could, that is, to idle properly at 10" BTDC bridged and not misfire but would not rev anymore than 3500rpm.

this made me feel warm inside knowing that a trained professional was as good as i was with my super cheap timing gun! anyways, he is going over everything ignition related and hopefully have it done by tomorrow. we both think that something else has gone wrong purely by coincident, there just doesn't seem to be any other explanation... will keep you all informed.

[sundee]

just remember that there is only 12 teeth on the dizzy, so when its out by ONLY 1 tooth, your actually throwing your ignition out by 30 degrees.

actually that might actually be 60 degrees since there is a 2:1 ratio between the crank pulley and the cam pulley's....someone else can do the maths!

either way its a fair bit.


depends what your refering to - it would be 60 crank shaft degrees or 30 cam shaft degrees.



and just FYI - here are all the manuals u need to diagnose any issue you have ... i have always been able to fix issues using them.

http://www.ae86drivingclub.com.au/forums/showthread.php?t=11915

this manual is golden!
http://files.aeu86.org/manuals/4age-diagnosis_manual-parrot.pdf

[sundee]

Question - what rpm is the engine idleing at when the timing is set 10' btdc?

[timbo]

between 700 - 800 from memory. nothing too low and def not above 900

[timbo]

folks, its the fucking ecu! so hit me up if you got a spare 100kw smallport ecu!

[sundee]

was going to say if your getting that rpm on idle with correct timing - then the timing is not the issue... ive got a gze ecu.. hhaha.. good to seee u found the problem man

[ke70dave]

what has lead you to this conclusion?

btw did you do a diagnostic check on said ecu?

[s14seriesII]

could be wiring issue..

get the ecu checked costs 60$ at any automotive service solutions store

[sundee]

just curious, when u say it wont rev past 3500.. is that just in nutural reving the engine or is that driving under load?

[timbo]

driving under load, it runs lean normally and will rev in neutral.

[sundee]

how old is the ingition coil? and have u tested that?

[timbo]

i'd say the coil is fairly old.

edit. looks like the coil is ok, reffering the the diagnosis manual all seems to be in order.

[timbo]

well, tried another ecu, still the same problem... im going to try the fuel system next. i guess a pressure test maybe a different pump? probably get the injectors cleaned for good measure too.

[sundee]

try bridging the fuel pump connector and driving it

[s14seriesII]

take a video of what its doing and post it up rather than swapping parts till you stumble upon whats wrong

[timbo]

try bridging the fuel pump connector and driving it

do you mean driving it without a fuel pump???


take a video of what its doing and post it up rather than swapping parts till you stumble upon whats wrong

will try and get one tomorrow. i don't see how it will be of much use though, it doesn't rev past 3500rpm under load...

[slide86]

starting to sound like it has no fuel pressure.

crimp the return line with pliers or vice grips then drive and see if its better

[sundee]

nah it make the fuel pump run constantly... i thought that if the rail was pressurised enough then u gave it a boot.. the 1 or 2nd time's it may not misfire as their would be sufficient fuel pressure in the rail...

just tossing up ideas.

[s14seriesII]

will try and get one tomorrow. i don't see how it will be of much use though, it doesn't rev past 3500rpm under load...


might be easier to diagnose from a video than your description.. no offence

[timbo]

nah it make the fuel pump run constantly... i thought that if the rail was pressurised enough then u gave it a boot.. the 1 or 2nd time's it may not misfire as their would be sufficient fuel pressure in the rail...

just tossing up ideas.

all good, will try that and let you know the results



might be easier to diagnose from a video than your description.. no offence

no offence taken, prob get it done tomorrow when someone can film for me whilst i drive and not crash...

[timbo]

ok, vids as requested. not great but you get the idea.

this is with the car in neutral:

http://www.youtube.com/watch?v=UIPJ7aGVeJA

this is driving with full throttle, it only just revs to 4000rpm, really struggled.

http://www.youtube.com/watch?v=6XCz5K5xj-g

[Nikkojoe]

Sounds like it's in limp mode sorta.....

Reminds me of when my bigport was running in limpmode, would rev to 4000 but not any further with WOT. However if you got to 4000rpm at wot and began to release, it would rev more...... It also had a miss when in limp mode.

Maybe check your distributor plug to see if there are any damaged wires/loose contacts and same with your ignitor aswell.

[timbo]

replaced the fuel filter today, made quite a noticeable difference. also cleaned the fuel lines and the pump works fine... (don't ask). so we are thinking it is the injectors. i did fuel up the same day as i replaced the dizzy o-ring so it could have been a bad batch. will post up details after cleaning.

[ke70dave]

have you done a diagnostic check on the ecu yet?

[Matt-AE86]

I think you might be putting it in 180 out, 2 times in a row is possible. You can spin the Crank to TDC 0 but be on a different stroke. The best way to check this is to have the dots on the Cam Gears line up with the lines on the back cover or there is a divet in the intake cam and you should be able to see it through the oil cap hole once on the right stroke of TDC.

Then line up the dots on the dizzy, hold the rotor button and dizzy with 1 hand and slot it in.

[timbo]

hold the rotor button and dizzy with 1 hand and slot it in.

that was the problem to begin with, i think it was jumping a tooth when i was putting it in...

timing is all good now, got that part sorted but the problem still persisted. i have checked all the plugs and connectors on the motor plus the pins on the ecu, all with in range/normal results then tried another ecu, problem still there.

we replaced the fuel filter (as mentioned above) and the car ran alot better. the old filter shat out some terrible coloured fuel so we are guessing it has fouled/blocked up the injectors. it just seems that this has happened by coincidence making it hard to properly diagnose the problem.

[sundee]

put 1/4 tank of 98 oct and a full bottle of nulon fuel system cleaner and take it for a HWY run..will give the system a good clean out

[timbo]

put 1/4 tank of 98 oct and a full bottle of nulon fuel system cleaner and take it for a HWY run..will give the system a good clean out

haha yeah, first thing i did after changing the filter! alot better but still has trouble revving so my only guess is the injectors need a good clean.

[s14seriesII]

cant tell anything from the video really its too short im guessing your in 2nd gear.. need to hold it at wot throttle for longer,

surgest a few things

shit fuel
kinked fuel line

maybe check with fuel pressure gauge when free revving and when driving ?

is it worse if you drive the car flat out when cold ?
or is it worse hot or no different ?

is the timing advancing as it should ?

should be between 32 and 42 deg advanced at 3500rpm upwards when free revving ( watch with a timing light)

air intake sucking closed ?

tvis operation ? maybe try disconecting this as im pretty sure its static position is open

[timbo]

cant tell anything from the video really its too short im guessing your in 2nd gear.. need to hold it at wot throttle for longer,

yeah my bad, need a better video converter

surgest a few things

shit fuel

i think thats what has caused it, changed fuel and used fuel dr

kinked fuel line

checked, all good

maybe check with fuel pressure gauge when free revving and when driving ?

don't have one, so going to have to get it checked by someone

is it worse if you drive the car flat out when cold ?
or is it worse hot or no different ?

no difference, car is never too happy when cold

is the timing advancing as it should ?

should be between 32 and 42 deg advanced at 3500rpm upwards when free revving ( watch with a timing light)

i shall check that

air intake sucking closed ?

nope, intake side of things is all good

tvis operation ? maybe try disconecting this as im pretty sure its static position is open

its a smallport, thus tvisless


i really think that bad fuel has fouled up the injectors. we blew out the fuel line, replaced the filter and there does seem to be alot of pressure but it does have to be checked.

[sundee]

so what happened when the car was in the shop? did the mechanic find anything wrong?

its been asked twice already but you havent answered - have u ran a diagnostic check??

have u thrown the multimeter over all the sensors? are they all within tollerance?

That video was no good - does it just die at 4000rpm or does it cough a plutter and misfire after 4000rpm?

post a video with a good amount of footage of WOT.

this is confusing - only other thing i can think if is have u tested the coil pickups inside the dizzy?

[timbo]

so what happened when the car was in the shop? did the mechanic find anything wrong?

no, he didn't find anything wrong

its been asked twice already but you havent answered - have u ran a diagnostic check??

sorry, the mechanic did, i was told it was normal. i also tried another ecu, no difference

have u thrown the multimeter over all the sensors? are they all within tollerance?

yes, and on the ecu aswell all with in range results

That video was no good - does it just die at 4000rpm or does it cough a plutter and misfire after 4000rpm?

the car can now rev past 4000rpm, after changing the fuel filter, but struggles. exhuast cam and manifold are both very hot which im sure means the car is running lean. will try to get a better video

this is confusing - only other thing i can think if is have u tested the coil pickups inside the dizzy?

everything has been checked!

so lets clear this up now. what i originally thought was a timing issue most likely seems to be fuel related. because the car was filled up the same day the dizzy seal was done we (myself, mechanic's and friends) assumed the car not running well was related to this. after days of timing and testing the car was infact timed perfectly but acted as if it was retarded due to a very lean fuel mixture. we cleaned the fuel lines and changed the fuel filter and instantly noticed a difference, the car rev'd past 4000rpm (not perfectly) and picked up about 4500rpm. the only conclusion that the mechanic and myself could agree on is that fuel system past the filter has been fouled up.

[DX20VT]

For what it's worth for you and future refrence for people who have the same problem and search thru posts,


If you are having real trouble setting the ignition timing,

you need to make sure that the TPS idle contacts are closing properly,

as not only do you need T and E1 bridged to correctly set timing,
the TPS idle contact must also be closed or the ECU does not return to the base timing of 10 deg.

I know as I have struck this many times on various 4AGE's over the years.

[timbo]

you need to make sure that the TPS idle contacts are closing properly

can you explain further? electrical contacts?

[Skylar]

TPS -> 4 pins 5v, ground, variable volt out and idle contact. It should be continuous (4-5kohm or so) then you move the butterfly some amount as shown in the manual and it goes to infinity telling the ecu that the engine is not in idle mode anymore.

[timbo]

ahhh righto. well i unplugged the tps and drove the car with no difference but i will check the idle contact. do i expect the multimeter to read high or go crazy?

[DX20VT]

ahhh righto. well i unplugged the tps and drove the car with no difference but i will check the idle contact. do i expect the multimeter to read high or go crazy?

with the TPS pluged in and the car turned on but not running,
check the voltage on the two centre pins.

Cant remember which is what from memory,
but one will vary as you move the throttle from about 0.5v up to 4.5v,
That one is the variable output and you are looking for the other wire.

It should read low voltage, 0.0 to 1.0v with the throttle closed
and read 10V or higher once you open the throttle slightly.

It must be at the low voltage to set ignition timing.

Now not 100% sure on this next bit as I have not tried it,
but if your setting the timing with T and E1 bridged,
and you unplug the TPS and the timing does not change,
then the TPS is probably set incorrectly.

[hachi_dk]

if my car was being a bitch like this it would be on fire by now

[H8CHIR6KU]

the tps shouldnt be a problem if it hasnt been touched tho

[sundee]

checked out the MAP sensor?

[DX20VT]

the tps shouldnt be a problem if it hasnt been touched tho

Only time it will be a problem is when your trying to set the timing.

If it has benn out for the last 3 years, you would not notice,

and they do go 'out of adjustment' over time as the contacts in them move.