ok well i have a 99 civic si turbo. i was in the middle of getting retuned and when i would let out of gear and my car would drop to idle it would die out. even after restarting it it wont stay idling it will just die out. then after we stopped and went back to the guys place i tried starting it again after a few minutes, it will hold idle for around a minute then it will die out and not hold idle anymore. also the speedometer stopped working after we got back and hasnt worked since so i have no idea what the problem is i will be trying a new speed sensor but still wondering about the idling issue we even tried uploading my original map back and the car is still dying out at idle. fyi i have 650cc precision injectors and a GM 3 bar map sensor.

 

Is dash fuse 15 blown?

 

i will check in a moment, just have to find the diagram for it since i dont have the cover.

 

also forgot to mention that i undid a vaccuum line in order to keep the car running at idle so i could get it home because i was about 2 hrs away from home. also the car wont go over 4500rpm's. i tried a different ecu as well and still the same result so first i will check to see if that fuse is blown then go from there.

 

 

thanks, i found it a few minutes ago finally lol. well i checked and that fuse is still good. any other ideas?

 

check to see if the iacv is opening at idle;
take your intake pipe off, inside the throttle body there will be 2 bypass holes, the upper one is for the IACV. Cover it with your finger and see if its sucking air.
If its not sucking air that's your problem, its either clogged or the piston inside the IACV is stuck or the ECU isn't telling it to open.
If the hole is sucking air, its not your IACV.

 

ok i'll do that later, its raining right now so i dont wanna get sick. would that maybe cause my car to go into limp mode?

 

well the iacv is sucking in air, when i covered the hole the car would idle real low until it finally died out. same thing happened when i closed up the tee on the vaccuum line it idled low then finally died out too. i checked the voltage on the vss and its around 4.6V give or take. so im still not sure why the speedometer isnt working either, the tach still works just not the speedometer.

 

Do you have a CEL? sounds like your IACV is fine.
For the speedo, it just suddenly stopped working? or did it used to bounce around or read inaccurate? could be a bad cluster, how many miles are on it?

 

Did you test the installed fuse with a test light as described here: -Test fuses

 

the speedometer stopped working after we stopped street tuning, worked fine before that other than when i was in boost it would get a little erratic. i took off the plug to the vss and put it back on and it worked for about 4 miles then it went all crazy and stopped working again. the cluster has about 65k miles on it

 

no i didnt test it i just replaced it with a brand new one and no luck. im gonna try a new vss and if that doesnt work then next will probably be a new vss plug since the current one doesnt look too good in terms of condition. my main concern for now is why my car wont stay idling w/o the need for a vaccuum leak of some sort, could the tps have been thrown off during the street tune maybe?

 

the speedometer problem is most likely the speed sensor.. those things are famous for going out. i've had the exact same thing happen to me a numerous amount of times on just about every honda i've owned at one point or another.

 

yeah thats what im thinking too, this would be the third one to go out on me now so it wouldnt surprise me too much, that or the plug is bad and needs to be replaced also. now i just need to figure out the idling issue. any ideas anyone? tps? could maybe have been thrown off when we were working on the tune?

 

ok well the problem with the vss was the plug and well the idle issue we couldn't really figure out so my tuner had to start fresh with another tune so yeah.