Ok so yesterday i installed my missing link(turbo isnt in yet) and i drove it to autozone a couple times and everything was fine. i drove to school today and everything was fine. on the way home i thought i hit something. then the sound came again and i realized i was misfireing. it only misfired a total of 3 times. ok then i pull to a stop light and the car dies. i try and restart it and it cranks but wont start. then i turn the key to off and then crank it again and it starts back up. well to make a long story short, if i let it lug down from anything higher then 3,000 rpms, when i give it gas to start accelerating again(just a tiny bit of gas) the manifold pressure(read off my s-afc) raises from -400 ish to -90 mmhg. when it does this, if i push the clutch in the car dies, and if i floor it, the car jerks, then the manifold pressure drops to where it should be and it drives normal again... i reset the ecu, and it still does it, but i dont have any CEL... wtf is going on here? sorry for the long post but any help is appreciated. thanks

-Chris

So it will drive normal again if you floor it?
Doesn't make much sence...

F*ck those safc's they cause uber problems and blow more motors then to much boost imo.

Do u have excessive blow by? Will the car even idle? If so, pull the dipstick and see if smoke plums out. compression tester?


Nick
97RS


THX KAPTAIN MYKE FOR HOSTING! www.kaptainmyke.com

Originally posted by Collente
So it will drive normal again if you floor it? Doesn't make much sence... F*ck those safc's they cause uber problems and blow more motors then to much boost imo. Do u have excessive blow by? Will the car even idle? If so, pull the dipstick and see if smoke plums out. compression tester? Nick 97RS THX KAPTAIN MYKE FOR HOSTING! www.kaptainmyke.com

Just because you can't manage to use an AFC right doesn't mean it doesn't do exactly what it is designed to do. Modify a MAP signal to either add or remove fuel (not so much add in our case). SAFC blow more motors than boost does ... that's ignorant too. Altering the MAP signal causes timing to be adjusted and if you're boosting. Too much timing advance under high load and heavy boost will lead to detonation. Detonation kills motors. If you blame your AFC for your motor's death you should really blame yourself because it's all user error.

Anyway, the problem should be pretty obvious. You just installed a new part right. What's it do ... it's a check valve that prevents positive pressure making it to the MAP sensor. Well check valves get stuck, messed up, whatever. Most likely it's not letting all the vacuum to be read by the MAP sensor. ECU seeing less vacuum ... more fuel ... run rich ... possibly misfire ... dies on decel because too much fuel is being dumped in without enough air. Probably because the valve is being stick. So, what should you do? Take out the MS you just installed. No problems before the install ... problems after the install ... take it out. It should've been the FIRST thing you tried. The MS ain't that grand. I tossed mine out when it would allow just a hair of positive pressure to cause fuel cut but at the same time wouldn't allow the MAP to see all the vacuum.

I'm talking about people's incompitence to the safc. It works great for the limited functionality it provides with our platform. But the only reason you even know about the timing advance problem is because someone blew up their shit up and they analized why and read timing when using the safc to make corrections based on map voltage. Even advanced users that I have known will make a simple mistake and BOOM. I've seen it first hand more then 5 times.

I would hope he tried to pull the ml first, then posting this after it didnt solve the problem.
Though my knowledge is still limited in comparison.

late!


Nick
97RS


THX KAPTAIN MYKE FOR HOSTING! www.kaptainmyke.com

Originally posted by Avenger

Originally posted by Collente So it will drive normal again if you floor it? Doesn't make much sence... F*ck those safc's they cause uber problems and blow more motors then to much boost imo. Do u have excessive blow by? Will the car even idle? If so, pull the dipstick and see if smoke plums out. compression tester? Nick 97RS THX KAPTAIN MYKE FOR HOSTING! www.kaptainmyke.com

Just because you can't manage to use an AFC right doesn't mean it doesn't do exactly what it is designed to do. Modify a MAP signal to either add or remove fuel (not so much add in our case). SAFC blow more motors than boost does ... that's ignorant too. Altering the MAP signal causes timing to be adjusted and if you're boosting. Too much timing advance under high load and heavy boost will lead to detonation. Detonation kills motors. If you blame your AFC for your motor's death you should really blame yourself because it's all user error. Anyway, the problem should be pretty obvious. You just installed a new part right. What's it do ... it's a check valve that prevents positive pressure making it to the MAP sensor. Well check valves get stuck, messed up, whatever. Most likely it's not letting all the vacuum to be read by the MAP sensor. ECU seeing less vacuum ... more fuel ... run rich ... possibly misfire ... dies on decel because too much fuel is being dumped in without enough air. Probably because the valve is being stick. So, what should you do? Take out the MS you just installed. No problems before the install ... problems after the install ... take it out. It should've been the FIRST thing you tried. The MS ain't that grand. I tossed mine out when it would allow just a hair of positive pressure to cause fuel cut but at the same time wouldn't allow the MAP to see all the vacuum.

thanks, i am going to take the missing link out, but i had to work tonight so i didt have time. i was asking more for why it is doing this, because im going to eventually have to put it back in when i put the turbo on. is there a way to check the ML or fix it? if not what do you recommend? thanks

-Chris

If it is a new one, you can clean the filter on the side (or just cut a new one). Make sure the seals arent pinched or ripped. Other then that, I cant think of anything else you'd be able to do.


Nick
97RS


THX KAPTAIN MYKE FOR HOSTING! www.kaptainmyke.com

Take out the Missing link and make sure none of the 0-ring seals are broken, on the missing link or the map sensor. Then put a little bit of oil on the o-rings of both the missing link and the map sensor. Not a lot it shouldnt be driping just a light glaze. Then re-install both. You are using a safc right? Well now u just modified the map sensor reading to not read correctly and to fool the safc so try changing your safc settings. Try 7 in 7 out. Then try 6 in 6 out. Then try 5 in 5 out. See which one works best. The night i installed my missing link i thought it messed up my car as well, it wasnt running right at all. The next day i brought it in the garage turns out my 02 sensor stripped out of my downpipe and was being dragged on the street through the snow :wallbash So if everything on the missing link looks correct try looking outside the box.

Originally posted by eclipse7782
Take out the Missing link and make sure none of the 0-ring seals are broken, on the missing link or the map sensor. Then put a little bit of oil on the o-rings of both the missing link and the map sensor. Not a lot it shouldnt be driping just a light glaze. Then re-install both. You are using a safc right? Well now u just modified the map sensor reading to not read correctly and to fool the safc so try changing your safc settings. Try 7 in 7 out. Then try 6 in 6 out. Then try 5 in 5 out. See which one works best. The night i installed my missing link i thought it messed up my car as well, it wasnt running right at all. The next day i brought it in the garage turns out my 02 sensor stripped out of my downpipe and was being dragged on the street through the snow :wallbash So if everything on the missing link looks correct try looking outside the box.

ok ill check all the seals. but im really not sure how so much emphasis is being put on the s-afc, because it has nothing to do with it. first off the ML is only suppose to protect the MAP from seeing boost, it shouldnt affect it at all when im not boosting, and second my S-afc isnt even correcting anything, i have all the settings at 0% right now. and changing the 6 in 6 out or whatver shouldnt really matter either since that doesnt affect how it modifies the signal, it only effects how it displays the manifold pressure. so lets forget about the s-afc right now cuz im positive its not the problem. ok so im gonna check the seals. is there any way to check the valve to see if its stuck at all? thanks

-Chris

its just like any other check valve like thura said. a way to test it is blow on one side and if air comes out the other, its not doing its job. or suck on either side and see what happens. i think your ML is just fucked up and needa a cleaning.

no vaccum leak by where you mounted it right?

Originally posted by turbo8u
its just like any other check valve like thura said. a way to test it is blow on one side and if air comes out the other, its not doing its job. or suck on either side and see what happens. i think your ML is just fucked up and needa a cleaning. no vaccum leak by where you mounted it right?

shit i didnt even think to check for a vac leak where its mounted, but im thinking its more the valve since it switches from perfect vac to shitty vac. but ill give that a check. im thinking it might be more of the valve is fucked up then dirty tho because its brand new. thanks for the help guys, ill do those tests and let you know whats up

Originally posted by GSGoinFast

Originally posted by turbo8u its just like any other check valve like thura said. a way to test it is blow on one side and if air comes out the other, its not doing its job. or suck on either side and see what happens. i think your ML is just fucked up and needa a cleaning. no vaccum leak by where you mounted it right?

shit i didnt even think to check for a vac leak where its mounted, but im thinking its more the valve since it switches from perfect vac to shitty vac. but ill give that a check. im thinking it might be more of the valve is fucked up then dirty tho because its brand new. thanks for the help guys, ill do those tests and let you know whats up

The blowing through test isn't very accurate. Like I said with mine, it more or less did the job it's was supposed to. It "passed" the blow through test just fine but if you actually monitored what the sensor was seeing with the MS in place you could see that it was preventing the MAP sensor from seeing the proper signal (either not enough vacuum or just a hair of positive pressure). Just comparing what the MAP sensor was seeing vs. what mechanical boost gauge was seeing made that very clear. It also didn't look like it let positive pressure through but in reality is little just a hair through causing it to fuel cut. I ended up chucking the MS for an adjustable voltage clamp. This way I can be certain the MAP sensor sees what it needs to while out of boost and not worry that the MS is blocking any sort of vacuum readings from the motor.

Originally posted by Avenger

Originally posted by GSGoinFast

Originally posted by turbo8u its just like any other check valve like thura said. a way to test it is blow on one side and if air comes out the other, its not doing its job. or suck on either side and see what happens. i think your ML is just fucked up and needa a cleaning. no vaccum leak by where you mounted it right?

shit i didnt even think to check for a vac leak where its mounted, but im thinking its more the valve since it switches from perfect vac to shitty vac. but ill give that a check. im thinking it might be more of the valve is fucked up then dirty tho because its brand new. thanks for the help guys, ill do those tests and let you know whats up

The blowing through test isn't very accurate. Like I said with mine, it more or less did the job it's was supposed to. It "passed" the blow through test just fine but if you actually monitored what the sensor was seeing with the MS in place you could see that it was preventing the MAP sensor from seeing the proper signal (either not enough vacuum or just a hair of positive pressure). Just comparing what the MAP sensor was seeing vs. what mechanical boost gauge was seeing made that very clear. It also didn't look like it let positive pressure through but in reality is little just a hair through causing it to fuel cut. I ended up chucking the MS for an adjustable voltage clamp. This way I can be certain the MAP sensor sees what it needs to while out of boost and not worry that the MS is blocking any sort of vacuum readings from the motor.

ok well i took the ML out, and i did the blow test and it all seems to work fine. the me nor my dad could feel any air coming through when i was blowing on it. one thing i did notice was that the O rings sit a lot deeper in the trench on one side then it does on the rest... i dunno if this is normal or not. ugghhh i dunno this ML has caused me a mess of problems... grrrr

clean it out with soap and water, let it dry and then try it. my car was studdering awhile back when going into boost, i washed my ML and i havent had one problem since. good luck homie

Originally posted by turbo8u
clean it out with soap and water, let it dry and then try it. my car was studdering awhile back when going into boost, i washed my ML and i havent had one problem since. good luck homie

clean the inside out? like the valve part? ill try it but im probably not going to reinstall it untill i put the turbo on. got all the parts i need except for a fmu, and i need to weld the manifold together and make the pipes. wish me luck. thanks

-Chris

Originally posted by GSGoinFast
i need to weld the manifold together and make the pipes. wish me luck. thanks -Chris

good luck :twitch

i personally never had any luck with check valves of any kind . they all cause my car to run worse even before i had put my turbo on. . i jus made a simple voltage clamp and it works much better...

"star turbo talon" custom FCD...thats what I have....