new rebuild+mods.setting up idle-problems
08-10-02, 08:26 PM
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new rebuild+mods.setting up idle-problems
yes,it looks like i am joining the rank of people with idle problems[i have been reading trough pages of'em].here is my deal:
87'n/a
new rebuild,just started it for the first time a couple days back.motor has s5 internals and t2 intermidiate housing along w/mild streeport.full dual exhaust[rb].i installed a s5 intake manifold,removed all emissions.
my problem is,i am completely unable to get a idle setup on it.i checked tps resistance[seems like there is a lot of fluctuation in the tps-the resistance keeps wandering around],but i set it up as best as i could[i understand the bigest problem with a out of whack tps is the effects on the acv,wich i dont have,so i'm thinking the tps is not my main prob.true?]so,with tps adjusted and green plug jumpered,even with the idle adjust screw all the way out[to max flow],it will not idle.i ended up unscrewing the dashpot thinggy,to act as throttle stop,wich allowed me to get a very rough idle at apr. 750rpm give or take a couple hundred rpm[motor surges].this allowed me to try and roughly check the timing.question on timing-acording to haynes,the pin should line up with theyr respective marks at 750 rpm-in the mazda manual[fc3s.org]it says leading timing 5*atdc,trailing 20* atdc....does that mean i have to advance the timing light 5* at idle to get the corect timing?or just leave it at 0*?anyway,thats about where i am at.resistance on CAS is fine,double checked that it was installed properly.resistance sweep on tps seems ok also.tried unplugging bac-no difference.from all the things i have read,i am a serious candidate for big vacum leaks-whats the best way to check for'em?carb cleaner?i was very meticulus with assembly,the few vacum hoses left ar all ok.gask-a-sinch on all gaskets[supposed to be the best according to mechanic friend who has helped me out].to further "spice"things up,taking it on a test drive,it seemd to warm up more then it should have..up to 193*,on a cool day[70*or so],i am running a griffin rad.,evans coolant and black magic electric fan.....just low speed crusing[also bad hesitation between 3-4k,have not realy gone higher,but i'll worry about that after i get a good idle].anyway-thats where i stand-frustration is running high-if you have any input,please help!sorry so long...
david
87'n/a
new rebuild,just started it for the first time a couple days back.motor has s5 internals and t2 intermidiate housing along w/mild streeport.full dual exhaust[rb].i installed a s5 intake manifold,removed all emissions.
my problem is,i am completely unable to get a idle setup on it.i checked tps resistance[seems like there is a lot of fluctuation in the tps-the resistance keeps wandering around],but i set it up as best as i could[i understand the bigest problem with a out of whack tps is the effects on the acv,wich i dont have,so i'm thinking the tps is not my main prob.true?]so,with tps adjusted and green plug jumpered,even with the idle adjust screw all the way out[to max flow],it will not idle.i ended up unscrewing the dashpot thinggy,to act as throttle stop,wich allowed me to get a very rough idle at apr. 750rpm give or take a couple hundred rpm[motor surges].this allowed me to try and roughly check the timing.question on timing-acording to haynes,the pin should line up with theyr respective marks at 750 rpm-in the mazda manual[fc3s.org]it says leading timing 5*atdc,trailing 20* atdc....does that mean i have to advance the timing light 5* at idle to get the corect timing?or just leave it at 0*?anyway,thats about where i am at.resistance on CAS is fine,double checked that it was installed properly.resistance sweep on tps seems ok also.tried unplugging bac-no difference.from all the things i have read,i am a serious candidate for big vacum leaks-whats the best way to check for'em?carb cleaner?i was very meticulus with assembly,the few vacum hoses left ar all ok.gask-a-sinch on all gaskets[supposed to be the best according to mechanic friend who has helped me out].to further "spice"things up,taking it on a test drive,it seemd to warm up more then it should have..up to 193*,on a cool day[70*or so],i am running a griffin rad.,evans coolant and black magic electric fan.....just low speed crusing[also bad hesitation between 3-4k,have not realy gone higher,but i'll worry about that after i get a good idle].anyway-thats where i stand-frustration is running high-if you have any input,please help!sorry so long...
david
08-11-02, 02:22 PM
#4
HAILERS
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Location: FORT WORTH, TEXAS,USA
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The marks ARE at five and twenty degrees. Set the cas so that the marks line up at idle.
Tps should be set with a fully hot engine. To check to see if you set it right, at idle put your meter up the back of the green/red wire on the tps connector(not the green connector, the tps connector located about six inches from the tps itself). Your meter should read one volt. If not turn the screw until you read one volt. This is to be done with all connectors on and the engine at idle. Negative lead of the meter to a good ground.
The tps itself does not set the idle of the car. You need to download the factory service manual at http://www.fc3s.com and download the Fuel section. It tells how to set the idle.
Install the initial set coupler (see manual).
Set the timing.
Set the tps.
Turn the screw on top of the dymanic chamber until you get 750 rpm(initial set coupler has to be installed).
If the 750 cannot be established, set the variable resistor(see manual).
If neither will establish the 750rpm, get a can of starter fluid and while idling spray joints where air might leak. Repair same.
Still no 750 idle? May have to find the primary throttle stop screw and crack it a touch. If you do so, reset your tps, it will have moved on you, maybe.
I have no personal knowledge of how a street ported engine reacts. There is a chance that the idle has to be set higher. Find someone who has one and ask. Or call the shop that did the street port.
Bac circuit from out of the ECU sounds dead . Maybe yes, maybe no. Read http://www.teamfc3s.org/info/articles/idle.html just the parts about the bac. Ignore turbo items.
Tps should be set with a fully hot engine. To check to see if you set it right, at idle put your meter up the back of the green/red wire on the tps connector(not the green connector, the tps connector located about six inches from the tps itself). Your meter should read one volt. If not turn the screw until you read one volt. This is to be done with all connectors on and the engine at idle. Negative lead of the meter to a good ground.
The tps itself does not set the idle of the car. You need to download the factory service manual at http://www.fc3s.com and download the Fuel section. It tells how to set the idle.
Install the initial set coupler (see manual).
Set the timing.
Set the tps.
Turn the screw on top of the dymanic chamber until you get 750 rpm(initial set coupler has to be installed).
If the 750 cannot be established, set the variable resistor(see manual).
If neither will establish the 750rpm, get a can of starter fluid and while idling spray joints where air might leak. Repair same.
Still no 750 idle? May have to find the primary throttle stop screw and crack it a touch. If you do so, reset your tps, it will have moved on you, maybe.
I have no personal knowledge of how a street ported engine reacts. There is a chance that the idle has to be set higher. Find someone who has one and ask. Or call the shop that did the street port.
Bac circuit from out of the ECU sounds dead . Maybe yes, maybe no. Read http://www.teamfc3s.org/info/articles/idle.html just the parts about the bac. Ignore turbo items.
08-12-02, 08:53 PM
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hailers-thanks very much for the reply.i was aware of the proper idle adjustment method.unfortunately,i have been unable to download the fsm[just plain old will not load..].the bac on a n/a has nothing to do with the idle,if there is no loads on,right?i have actually narrowed my problem down to a vacum leak-using carbcleaner.it seems to be leaning out the mixture enough to make my headers glow cherry red hot[just today,i had some time to mess with it].i read through a lenghty thread from thepartstrader,he had the same problem[glowing headers]and it was a vacum leak.so,i'm pretty hopeful that this will fix my problem.what do you use for gasket mating surfaces?
thanks again
david
thanks again
david
