Justinmnhall

So I have 94 dx that ran rough, code 3 so I modified the the harness ocordingly added in a map sensor no codes now, the throttle body did not have map (not orig tb) now the idle surges, cleaned tb, the 2 sensors on tb and bleed the coolant for about 20 min till only fluid out bleeder. When I pull off map vaccum Line off and plug tb vac line, idle calms down but still rough and no codes? Any ideas?

speedjunkie_g35

Vacuum leak

Justinmnhall

I've replaced vac lines to map with new and still same

speedjunkie_g35

Almost positive you have a leak somewhere. Check all your lines!

Eg5ir1

Hi. I've delt with surging idle before and it's no fun when you can't figure out what's the cause of that annoying idle. Google " eric the car guy how to fix idle problems" . He takes you thru the basics of how to troubleshoot your idle problems . Hope this helps.

Justinmnhall

I've sprayed everywhere and no change . Throwing ideas out there before I take intake off. How about valve lash? I'll measure after the motor is cold. The pcv valve or the check valve under the intake mani? No codes but maybe the map sensor itself? Test at is new but anything to do with cooling ? Water pump is new as well fan comes on so I think sys is good. Have not bleed brake system yet?

FairlyImprudent

I had the same problem with the map sensor. There was no plug on my harness and I had to wire it to the ecu. Fixed the code but still surged. And it's not the sensor if you unplug it and the problem persists.
Try cleaning the IACV
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2Ahow-clean%2A%2A%2A-your-iacv-k-idle-air-control-valve-1575913/
And the FITV
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/

I did both and it helped but it didn't fix it. I kept spraying carb cleaner all over to find the leak and it took more than a few tries until I found it was coming from between the brake cylinder and brake booster. It was missing a rubber gasket. It's unlikely you have the same problem but I'm just trying to show that you have to be thorough.

Justinmnhall

Lol well i did have to install the brake booster( this car was stripped!!) so I'll check that too

p3p69

i had same issue with after market tb mine was the o-ring behind where the throttle cable hooks on hope this helps

FairlyImprudent

It's a little rubber gasket ring. Take off the brake cylinder and you'll see it. I'd spray carb cleaner or something there to confirm it before taking it off. Or that's gonna be a waste of time bleeding the brakes again

Justinmnhall

Ok so I pulled th brake line and blocked it off completely, no change. I blocked the upper hole inside the throttle body and no more up and down idle. So...... What does that go to and if that can be adjusted?

Justinmnhall

By the way I have already cleaned both fitv and iacv

FairlyImprudent

the brake line?

did you adjust the fitv?

you have a vacuum leak. try this. cover the entire throttle body. your engine should choke out and die. or you have a vacuum leak somewhere

Justinmnhall

So I didnt adjust the fitv put it back where it was should I adjust it? So covered tb and it died

FairlyImprudent

Then there isn't a big enough leak to cause those problems. Go back and look at that link. You can tighten it all the way down and seal it off. It's not a necessary part. Just good for warming the car up on cold starts

Justinmnhall

I turned it all the way down (fitv) started up. It was good for about 20 sec then back to the surging. Still no codes

FairlyImprudent

maybe you just have to reset the ecu since adding the map sensor. You can try unhooking the battery for the night and try again the next day. Wouldn't waste much time and effort if it doesn't work. I'm not very knowledgeable about what else to do at this point. I never had to deal with anything more after adding a map sensor and fixing my vac leak

Justinmnhall

Each time I turn off car I unplug battery and ecu fuse so I'm lost Lol

FairlyImprudent

Which hole in the throttle body did you plug that stopped the surging?

Justinmnhall

The top one that goes to the iac

FairlyImprudent

I think either you have a bad sensor reading or maybe your throttle isn't closing all the way when idling. Clean it if necessary and make sure the throttle cable isn't too tight

FairlyImprudent

You can also try unplugging the IACV and if it stops then your IACV is bad

Justinmnhall

Well I believe I fixed the issue. The tb was from another car and the set screw that sets the idel was too high, lowered the screw so throttle plate could close more and the surging went away