Timing and idle speed issues
12-27-10, 11:50 PM
#1
Livin fo the citaaay!
Thread Starter
Timing and idle speed issues
This is mainly for aaron cake everyone to view...short story:
87 na fc...
swapped in jdm t2 91 motor, tranny, diff, etc...
after a wiring nightmare and untold amounts of heartaches and headaches i finally got her running pretty darn close to spot on.
last is to get the timing and idle set to the sweet spot.
in the pictures and video, the car was checked with a timing gun and it was reading 5 degrees ATDC with the cas turned all the way to one side...idle is just a little high...
and before anyone says anything about turning the adjustment on the bac, there is no adjustment screw like the fsm says for the jdm motors...well more specifically for the jdm UIM and BAC. So...aaron whats the prognosis?
and the video
(i put a direct link so that it wouldn't slow this thread down too much...)
http://s18.photobucket.com/albums/b1...t=MVI_1479.mp4
87 na fc...
swapped in jdm t2 91 motor, tranny, diff, etc...
after a wiring nightmare and untold amounts of heartaches and headaches i finally got her running pretty darn close to spot on.
last is to get the timing and idle set to the sweet spot.
in the pictures and video, the car was checked with a timing gun and it was reading 5 degrees ATDC with the cas turned all the way to one side...idle is just a little high...
and before anyone says anything about turning the adjustment on the bac, there is no adjustment screw like the fsm says for the jdm motors...well more specifically for the jdm UIM and BAC. So...aaron whats the prognosis?
and the video
(i put a direct link so that it wouldn't slow this thread down too much...)
http://s18.photobucket.com/albums/b1...t=MVI_1479.mp4
12-28-10, 12:00 AM
#2
If warm idle speed is high, you can adjust the throttle stop. It's the spring-loaded screw in the picture 2nd from the bottom.
What the heck is the large gauge black wire connected to a red wire with spade connectors? I hope that isn't carrying power with the connection completely uncovered.
What the heck is the large gauge black wire connected to a red wire with spade connectors? I hope that isn't carrying power with the connection completely uncovered.
12-28-10, 05:34 PM
#3
Livin fo the citaaay!
Thread Starter
that screw (the throttle stop screw) isn't actually doing anything...the throttle is stopping before it even reaches that screw...and im going to cover that red wire connection up when i start driving it around...
even if i back out that throttle stop screw it doesn't seem to make the throttle change position...
even if i back out that throttle stop screw it doesn't seem to make the throttle change position...
12-28-10, 06:27 PM
#4
12-28-10, 09:40 PM
#5
Livin fo the citaaay!
Thread Starter
i can try restabing the CAS and take some pictures of it if that's what you guys think might be the culprit for the higher idle...but the couple times i did before it seemed that when we checked it with the timing light it was waaay off...but it sounded good and was nice and low...ill see what i can do tomorrow when i get daylight...still waitin to hear from aaron cake who was helpin me out with this.
12-29-10, 02:09 AM
#6
How tight is that throttle cable? I can see you flipped the throttle assembly around, and used an NA cable, but is the cable binding at all? Back when I put an S5 intake manifold on my S4 NA engine, I had to buy an S5 NA throttle cable to go with it because the S4 cable was taking too sharp of a turn. The cable did not move freely, and would cause the throttle to stick open slightly, which would of course raise idle speed.
That throttle stop should only have a gap if the thermowax is cold. When it warms up, the metal arm should rest against it. If it doesn't, the thermowax is not working properly, or your cable is binding.
That throttle stop should only have a gap if the thermowax is cold. When it warms up, the metal arm should rest against it. If it doesn't, the thermowax is not working properly, or your cable is binding.
12-29-10, 07:40 AM
#7
Rotary Freak
The ECU all by itself advances the timing when the engine speed goes over 1100-1200 rpm. Sooooo I'd say the problem there is not timing/CAS related. So it must be mechanical.
I'd go to the screw that sits on top of the water thermos sensors piston.......and screw that screw all the way clockwise (all the way in). That should assure you that the thermowax linkage is not the problem. I'd do that after you make sure the throttle cable is not too tight as mentioned in the posts above.
If the cable has a bit of minor slack in it as it should..........then with a fully hot engine......reach over and with your hand try to make the throttle linkage go closed. If the idle speed drops........well write back if it drops.
The linkage not hitting against the small throttel stop screw indicates the fast idle cam is not seperating from the roll pin. Turning the screw that rests on top of the water themo sensors piston should seperate the cam and roller if that screw is turned all the way clockwise as mentioned before.
If that does not work ..........I'd go look at the throttle plates somehow with the engine warmed up and see if the gap b/t the plates and the throttle body is too large. The manual says???????? .017 gap????? Something like that.
Of course if the other screws on the body have been fiddled with a bit too much they could be causing the plates to be open too far.
I think your timing problem will go south when the idle speed gets below 1000 rpm. If the rpm is under 1000 rpm and you still read advanced as you posted.........then there is a CAS timing problem. But I'd bet your idle is over 1200 and that is the *timing* problem. IN other words not a timing problem but a fast idle problem.
I'd go to the screw that sits on top of the water thermos sensors piston.......and screw that screw all the way clockwise (all the way in). That should assure you that the thermowax linkage is not the problem. I'd do that after you make sure the throttle cable is not too tight as mentioned in the posts above.
If the cable has a bit of minor slack in it as it should..........then with a fully hot engine......reach over and with your hand try to make the throttle linkage go closed. If the idle speed drops........well write back if it drops.
The linkage not hitting against the small throttel stop screw indicates the fast idle cam is not seperating from the roll pin. Turning the screw that rests on top of the water themo sensors piston should seperate the cam and roller if that screw is turned all the way clockwise as mentioned before.
If that does not work ..........I'd go look at the throttle plates somehow with the engine warmed up and see if the gap b/t the plates and the throttle body is too large. The manual says???????? .017 gap????? Something like that.
Of course if the other screws on the body have been fiddled with a bit too much they could be causing the plates to be open too far.
I think your timing problem will go south when the idle speed gets below 1000 rpm. If the rpm is under 1000 rpm and you still read advanced as you posted.........then there is a CAS timing problem. But I'd bet your idle is over 1200 and that is the *timing* problem. IN other words not a timing problem but a fast idle problem.
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12-29-10, 11:36 AM
#8
Livin fo the citaaay!
Thread Starter
wow...ok lots of good info here. i gotta go to work and its raining today (of course when i'd actually have time to check it) but if it stops when im off i will be checking these things guys.
ill also post back up here most likely a little after 3pm pst with some more info hopefully.
rocket: are you sure that the assembly is flipped around? I have suspected that maybe when my good friend who did the swap initially for me flipped it around but i haven't been able to verify this...just a reminder it is a jdm s5 block...perhaps if this was for sure, he left it too open (i.e. the plates are too open?)
check the video link (which im assuming you have already) and please lemme know...maybe this is the culprit...
hailers: ill get back to you on those things once im off work and if the rain stops today enough for me to get my hand on it.
thanks again guys!
ill also post back up here most likely a little after 3pm pst with some more info hopefully.
rocket: are you sure that the assembly is flipped around? I have suspected that maybe when my good friend who did the swap initially for me flipped it around but i haven't been able to verify this...just a reminder it is a jdm s5 block...perhaps if this was for sure, he left it too open (i.e. the plates are too open?)
check the video link (which im assuming you have already) and please lemme know...maybe this is the culprit...
hailers: ill get back to you on those things once im off work and if the rain stops today enough for me to get my hand on it.
thanks again guys!
12-29-10, 11:57 AM
#9
Two doritos, on a stick..
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I agree with the above steps, definately make sure the throttle cable is the right length can move freely. Having been in the same situation and eliminated all the above problems, i found a vacuum leak to be the problem in my case. Un metered air from a busted plenum gasket or from disconnected vacuum lines can raise idle as well. Best of luck! 
12-29-10, 12:18 PM
#10
Rotary Freak
In your third picture showing the side of the engine with the BAC. Below the BAC are three small hard lines that once upon a time controlled the ACV which is now off the car and a blockoff plate is in the place of the ACV. Well on a NORMAL car, one of those three small hard lines should have a vacuum on it at idle . Make sure when it's idling neither of the three has a vacauum on it.
Probably not. You probably have the rest of the vacuum tubing removed or disabled.
Throttle cable is not normal imho. But you know that I suppose. I assumed you know what the thermowax and it's piston is so you can find the screw I mentioned that sits on the thermowax's piston. Way it works is......engine water heats up.............thermowax piston moves/expands out from its body...........piston pushes up on the screw that rides on it........screw is connected to the cam and roller which in turn seperate when the piston expands far enough and THAT causes the throttle linkage to move towards the throttle stop screw. Throttle stop screw on a series four is about a half inch long with a 8mm jamnut holding it in position. I'm missing seeing the stop screw in your pictures. Maybe I didn't look hard enough.
Like I say........throttle linkage looks funky and not normal. Almost like it's not pulling in the right direction. Hybrid I suppose. Matters not if there is just a hint of slack in the throttle cable.
EDIT: I didnt read all this thread. It's obvious now that I looked harder.........the cable is not turbo but non turbo I suppose. Turbo cable comes from the drivers blkd..........goes fwd around the front of the engine.............then down the right side of the engine to a bracket on the aft side of the engine and pulls the throttle bellcrank etc towards the right side of the car. Your is funky non stk but probably works anyway.
I thought all people got off for the holidays from the day before Christmas to the new year. Oh well. sounds like slavery working today. One of those Social Justice things we need to work for. humor
Probably not. You probably have the rest of the vacuum tubing removed or disabled.
Throttle cable is not normal imho. But you know that I suppose. I assumed you know what the thermowax and it's piston is so you can find the screw I mentioned that sits on the thermowax's piston. Way it works is......engine water heats up.............thermowax piston moves/expands out from its body...........piston pushes up on the screw that rides on it........screw is connected to the cam and roller which in turn seperate when the piston expands far enough and THAT causes the throttle linkage to move towards the throttle stop screw. Throttle stop screw on a series four is about a half inch long with a 8mm jamnut holding it in position. I'm missing seeing the stop screw in your pictures. Maybe I didn't look hard enough.
Like I say........throttle linkage looks funky and not normal. Almost like it's not pulling in the right direction. Hybrid I suppose. Matters not if there is just a hint of slack in the throttle cable.
EDIT: I didnt read all this thread. It's obvious now that I looked harder.........the cable is not turbo but non turbo I suppose. Turbo cable comes from the drivers blkd..........goes fwd around the front of the engine.............then down the right side of the engine to a bracket on the aft side of the engine and pulls the throttle bellcrank etc towards the right side of the car. Your is funky non stk but probably works anyway.
I thought all people got off for the holidays from the day before Christmas to the new year. Oh well. sounds like slavery working today. One of those Social Justice things we need to work for. humor
12-29-10, 11:21 PM
#11
Livin fo the citaaay!
Thread Starter
Sorry gentlemen...the rain today in southern california would not permit me to go and work on the car today...
i keep reading everyone's posts and thinking very hard about what's being said until i get to go out and put my hands on it.
hailers: the throttle cable IS from an N/A indeed my friend. my good buddy who did the swap made it so that i could run the stock s4 n/a cable to the jdm s5 t2 throttle body...in doing this, i have been thinking about what he had to change/modify and could that have possibly changed things with the throttle plate? maybe it's "stock" location has been moved open more and its raising the idle? Perhaps that's why the "idle stop screw" doesn't effect the throttle position at all as far as moving back down? Does that make sense? Im just spit-balling here, but im trying to figure out what exactly he would've had to change in order to adapt this throttle to my cable...
oh and for anyone thinking that the cable is pulling on it and holding the plates open it is most definitely not...i have thought about that many times and checked to see that there's some slack on it and its not pulling the throttle open....so that part is fine..but perhaps the initial location that the valve is set at is wrong?
i keep reading everyone's posts and thinking very hard about what's being said until i get to go out and put my hands on it.
hailers: the throttle cable IS from an N/A indeed my friend. my good buddy who did the swap made it so that i could run the stock s4 n/a cable to the jdm s5 t2 throttle body...in doing this, i have been thinking about what he had to change/modify and could that have possibly changed things with the throttle plate? maybe it's "stock" location has been moved open more and its raising the idle? Perhaps that's why the "idle stop screw" doesn't effect the throttle position at all as far as moving back down? Does that make sense? Im just spit-balling here, but im trying to figure out what exactly he would've had to change in order to adapt this throttle to my cable...
oh and for anyone thinking that the cable is pulling on it and holding the plates open it is most definitely not...i have thought about that many times and checked to see that there's some slack on it and its not pulling the throttle open....so that part is fine..but perhaps the initial location that the valve is set at is wrong?
12-30-10, 12:10 AM
#12
Livin fo the citaaay!
Thread Starter
oh quick question i figured id put in here before bed...anybody got any pictures of an jdm s5 swap with the throttle cable from the usdm t2 on hand? I would really like to compare the position of the throttle linkage and see if its different than my own...that would answer that question and maybe be the fix i need...thanks guys! ill check tomorrow again before work. same thing for me tomorrow...
darn "Social Justice" things....lol!
darn "Social Justice" things....lol!
12-30-10, 12:40 AM
#13
All turbo engines worldwide have the cable pull from the passenger side. LHD cars just have the cable go way the hell around the front of the engine, then to the back side before connecting. You have it pulling from the driver's side (like an NA engine), which isn't normal. Someone has done this: https://www.rx7club.com/showthread.p...throttle+cable.
My engine is an S4 J-spec turbo with a US TII throttle cable. No difference at all with how the throttle plates are pulled open. The S5 is the same. Here's a picture for you of the back side of my engine:
My engine is an S4 J-spec turbo with a US TII throttle cable. No difference at all with how the throttle plates are pulled open. The S5 is the same. Here's a picture for you of the back side of my engine:
12-30-10, 09:17 AM
#14
Rotary Freak
https://www.rx7club.com/showthread.p...light=roll+pin
Go to that thread and look at the jpgs there. I posted one out of the fsm showing the cam/roll pin and then the owner of the thread showed real pictures of a throttle body showing the roll pin and cam. Roll pin had a green dot painted on it if I remember right.
The idea here is: the cam has to seperate or leave contact with the roll pin in order for the throttle plates to fully close. When that happens the linkage will either touch the small throttle stop screw or come darn close to touching it.
If you find the screw that rests on top of the water thermowax piston....well just lift up on that screw and the linkage should now cause the throttle plates to close. If you just turn that screw all the way clockwise ....then you get the same result i.e. the cam/roll pin seperate and the throttle plates now close all the way. Proven by the linkage coming in contact with the throttel stop screw.
If your water thermowax has been removed........then ignore this post. But I remember seeing your water thermowax in one of your pictures I think.
HINT: Roll pin is the item with the green dot on it. Cam is a flat piece of metal slightly curved that rests on the green dotted roll pin. You might read that whole post 'cause it seems to be dedicated to setting the throttle plates or something in that vein.
See post #21 with the pictures in the link I gave. It shows the cam/roll pin touching and then in the next jpg he lifts the screw upwards and the cam/roll pin seperate causing the throttle plates to fully close.
Go to that thread and look at the jpgs there. I posted one out of the fsm showing the cam/roll pin and then the owner of the thread showed real pictures of a throttle body showing the roll pin and cam. Roll pin had a green dot painted on it if I remember right.
The idea here is: the cam has to seperate or leave contact with the roll pin in order for the throttle plates to fully close. When that happens the linkage will either touch the small throttle stop screw or come darn close to touching it.
If you find the screw that rests on top of the water thermowax piston....well just lift up on that screw and the linkage should now cause the throttle plates to close. If you just turn that screw all the way clockwise ....then you get the same result i.e. the cam/roll pin seperate and the throttle plates now close all the way. Proven by the linkage coming in contact with the throttel stop screw.
If your water thermowax has been removed........then ignore this post. But I remember seeing your water thermowax in one of your pictures I think.
HINT: Roll pin is the item with the green dot on it. Cam is a flat piece of metal slightly curved that rests on the green dotted roll pin. You might read that whole post 'cause it seems to be dedicated to setting the throttle plates or something in that vein.
See post #21 with the pictures in the link I gave. It shows the cam/roll pin touching and then in the next jpg he lifts the screw upwards and the cam/roll pin seperate causing the throttle plates to fully close.
01-02-11, 12:58 AM
#15
Livin fo the citaaay!
Thread Starter
hopefully tomorrow ill get some time to take a couple more pics...and another video or two...i adjusted the screw that rests on the piston for the thermowax...it didn't seem to do anything...and then i thought about the tps once more...it occured to me that we adjusted the tps when i had my old ecu on...so i took out the n370 i was borrowing from my buddy and threw the n374 chipped ecu that i have and bam...just like that the idle dropped about 100 so now its at about 900-950 when warmed up...
on last thing i was also thinking about...could any missing or connections be effecting my idle? ill take a picture or two of the plugs around the passenger side and ecu and maybe you can think of an empty plug that could be hindering any performance...just a thought that occurred to me...since i was looking a few days back and realized that i have several plugs that are open.
oh and happy new year you guys...hope yours was great!
on last thing i was also thinking about...could any missing or connections be effecting my idle? ill take a picture or two of the plugs around the passenger side and ecu and maybe you can think of an empty plug that could be hindering any performance...just a thought that occurred to me...since i was looking a few days back and realized that i have several plugs that are open.
oh and happy new year you guys...hope yours was great!
01-02-11, 10:12 AM
#16
Rotary Freak
hopefully tomorrow ill get some time to take a couple more pics...and another video or two...i adjusted the screw that rests on the piston for the thermowax...it didn't seem to do anything...and then i thought about the tps once more...it occured to me that we adjusted the tps when i had my old ecu on...so i took out the n370 i was borrowing from my buddy and threw the n374 chipped ecu that i have and bam...just like that the idle dropped about 100 so now its at about 900-950 when warmed up...
on last thing i was also thinking about...could any missing or connections be effecting my idle? ill take a picture or two of the plugs around the passenger side and ecu and maybe you can think of an empty plug that could be hindering any performance...just a thought that occurred to me...since i was looking a few days back and realized that i have several plugs that are open.
oh and happy new year you guys...hope yours was great!
on last thing i was also thinking about...could any missing or connections be effecting my idle? ill take a picture or two of the plugs around the passenger side and ecu and maybe you can think of an empty plug that could be hindering any performance...just a thought that occurred to me...since i was looking a few days back and realized that i have several plugs that are open.
oh and happy new year you guys...hope yours was great!
01-02-11, 09:50 PM
#17
Livin fo the citaaay!
Thread Starter
whoa...ok now im trippin hailers...where did you read that i said the timing was advanced? im not seeing that...are you switching atdc with advanced timing?
01-03-11, 05:08 AM
#18
Rotary Freak
Could it be a vacuum hose on the intake is in the wrong place? Is the boost/pressure sensor for a turbo or is it non turbo?
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