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TSX TB Help: RPM Jump/Cruising Idle Surge

7K views 7 replies 4 participants last post by  J-Ro 
#1 ·
The problem at hand:

Ok need some help, I just installed a TSX throttle body using a Z3 paper gasket, P2R spacer and then thermal gasket. But of course I've got a problem. I have a idle surge. It occurs under two different circumstances. First with the car not moving, giving it gas off idle it will rev up fine fall to about 1k then back up to 2k then slowly back down to idle. 2nd, while cruising when clutch is depressed and no throttle the rpms drop to about 1k then back to 2500k and repeats that till the car stops them it will slowly makes way back to idle. The car idles steady at 850 with no accessories on. Climbs through the rpms fine all the way to redline. Another issue I've noticed is the rev hang is worse than it used to be. It almost revs up between gear changes. And while cruising if I let off the gas while still in gear it takes a full second before throttle is pulled and the car starts decelerating.

What I've done to try and fix:

I've followed the first post of this thread http://www.8thcivic.com/forums/diy-honda-civic-engine/222443-diy-throttle-body-calibration-procedure.html step by step( other than using flash pro as I currently do not have it, only engine mods I have are the throttle body and spacer). I did the idle relearn(vit vipers process),pulled the dbw plug, adjusted the set screw till it idled at 1K, turn the car off, plugged in dbw, then key back to run position, tested voltage and adjusted the set screw accordingly, both are within spec(note i used the battery ground instead of SG if that makes a difference), turned key off and waited, started car and let idle for maybe 10mins or more, took it for a 10min drive, let it cool down then drive it again for maybe 30-40mins, let it cool again, then another 30-40min drive...still have same symptoms with no improvement.

My next step as of now:

I'm going to drive it all week and see if it improves, if not then my only theory is a small vacuum leak somewhere. I have a HPS intake tube on the way so next weekend when I put that in I may pull the TB and reinstall to make sure everything is sealed well. I've ready through countless threads on this and similar issues with no real answer, Any help or thoughts would be great!

Update:

Got about an 8 min drive to work this morning, still had the same symptoms except I noticed when I parked it was idling at 750 so maybe that was a sign of things fixing themselves. So on my first break today I went out and started it and let it run for 20mins. Rad fan kicks on 3 times during the 20mins, but idled at 850 the whole time. Did a few throttle blips and it would rev up fine then drop to about 1k and back to 1500 then slowly back to the 850 idle...Everytime.

Update:

So I decided to try the relearn again, this time I disconnect both battery cables and left them touching each other for a little over an hour. Then started the car and let it run for 30 mins. At this point it was idling at 850, so I turned the car off and restarted it quickly and rpms jumped to 2k and slowly came back down to 850 again. Still does the idle jump when I blip the throttle, revs up fine falls to about 1100 then up to 1400 then slowly back to 850. I'm stumped, oy thing I can think of is a very small vacuum leak. Note it still rpm jumps by maybe 500 between shifts, not to be confused with idle surge, along with a slow idle surge when coasting in neutral...i also restarted the car a few times (fully wamed up) and evertime upon startup the rpms jump to 2k then slowly come down to the idle of 850.
 
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#4 ·
Definetly sounds like a vacuum leak, climbing to 2k means the ECU will have pulled timing down to -5 degrees but the revs climbed anyways.

This is a common problem when installing a TSX TB with Gaskets. Take the TB off, inspect the gaskets to make sure they are the right gasket for your IM and TB, meaning its very common to have the incorrect gaskets which will have ports where you shouldn't have them, and some won't be blocked by the gasket when they should be. Also, if the two gaskets are different, then air can escape between them, as Teflon and Paper don't seal well to each other. Also make sure the gaskets are on the right way.

Personally, I don't use the P2R spacer, just the Teflon gasket it comes with, then I remove the coolant lines to the TB every bit as effect and once less then to go wrong.

If you had a FlashPro, you could make a long and send it to us for review, I could tell right away what was up.

Hope that helps,

Steve
 
#5 ·
Thanks for the reply!

I'm picking up a new TB gasket and pulling everything off inspecting it all, my guy says it's a vacuum leak somewhere like you mentioned. I may even try it without the spacer like you mentioned.

Yeah Flashpro is definitely the next purchase!
 
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