Civic Racer X 7

got tuned in on the dyno yesterday and everything is running real smooth

98 civic hatch stock Y7(non vtec) with a y8 manifold and tb swap

the IACV has been cleaned and it idles good somtimes but sometimes after i warms up it will bounce from 1000-1400

considering there is no vacuum leaks and the iacv is good

will running an OBD1 P28 effect the Intake air temp sensor that I taped to the firewall?

and can I adjust the FTIV screw on the TB without throwing my tune off?

Luserkid

When exactly does the idle flucuate? Car warm or car cold? I ask because that could be signs of a bad IAC, or because of your FTIV passage (you dont have a direct FTIV that you could take out and screw down).

Also you could have a bubble in your coolant which is causing this problem as well. Last thing i could think of at this time would be a small hole in one of your vac. lines.

Civic Racer X 7

it does not do it cold

only warmed up and vacuum lines are good

the y8 has an adjustment screw on it can I adjust it without throwing the tune off?

hondaboy4life

i was running a chipped p28 on uberdata for my turbo obd1 b16, it also had this. where sometimes it would idle smooth and sometimes it would just do waht u said. mine also ahd 3k cold idle tho . my tuner and i couldnt figure it out. If you do figure it out let us know!

Civic Racer X 7

it has like a 2500 cold idle

Civic Racer X 7

wow now this is weird

I unplugged the bov to make a vacuum leak and it idles perfect then as soon as I put it back on and seal it up it begins to surge again

neocrynym

your setup is a bit TOO sealed, it's not getting enough air to keep it idling correctly.

Civic Racer X 7

ok so what can I do?

SE7EN3S

Have you measured the Voltage on your TPS since you swapped TB's?

Civic Racer X 7

mechanic at the shop set it up with a multimeter
since we had to swap sensors

littleredcivic

intake air temperature should change the air/fuel mix. this will make your idle unstable because the reading is not the same all the time. tap yourself a hole and put it back into the manifold. coolant temp, air temp, load, rpm, o2 signal...they all can change the output of the ecu.

SE7EN3S

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civic Racer X 7 &raquo;</TD></TR><TR><TD CLASS="quote">mechanic at the shop set it up with a multimeter
since we had to swap sensors </TD></TR></TABLE>

Cool. When I put my turbo on I was having the same problems. I ended up getting a Edelbrock Integra Type R Throttle body. They come with precalibrated TPS sensors and have a kick *** idle adjuster screw! Solved all my idle problems. Just an FYI, I guess. Good Luck dude, I know it can be annoying as hell.

salesmonkey

this Happened to me but mine was a stupid mistake on my part. Check the throttle cable and see if you tightened it to much. i wasnt sure where to put it when i was putting my engine back in becuase i pulled it(doing a clutch replacment to Stage 5 clutchmasters!!). and i ended up driving it around before i got it tuned at like 2500 3000 idle. when me and my friend figured it out i felt stupid. hopefully thats all it is for you.

The_Todd

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civic Racer X 7 &raquo;</TD></TR><TR><TD CLASS="quote">wow now this is weird

I unplugged the bov to make a vacuum leak and it idles perfect then as soon as I put it back on and seal it up it begins to surge again</TD></TR></TABLE>


When I first had mine boosted my idle screw was too 'loose' and with full vacuum it would idle shitty when warm but when I undid the bov it fixed everything. Try loosening the idle screw just a bit or tighten it down depending on what works for you.

Hope this helps.

edit: I don't see how this would 'throw off your tune' since your tune isn't dependent on your idle screw.