SOHC_2_DOHC

I blew my last OBD-1 Jdm D15b motor that was Greddy boosted on my 95 civic hatch. I installed another one and know i have an idle problem sometimes which surges between 1500 and 2000 rpms. I checked all vacume lines and i cleaned my iacv with carb cleaner but still the same thing. I think it might be the map sensor because i checked my codes and im pulling a Code 3 but it again comes on from time to time when i really pull hard. Maybe i just need a good tune!! Please help!!!!!!!!!!!!!!

SOHC_2_DOHC

anyone??

moores55

could be your tps is bad. could be you need a tune. Base maps are just that, something to get you to a tuner.

SOHC_2_DOHC

That is all true!!

ILcrxsi1

My friend and I both have jdm d15b's in our cars. They both have surging idles when it's cold outside. Whenever the temperature drops below 60 outside the idles start to surge. We've tried everything to stop it, cleaned the idle valve, bled the coolant, checked the tps, ecu's aren't throwing any codes. The only thing that stopped it on my car was going turbo and getting hondata on a different ecu than the p08. His car is still NA and still surges with the stock ecu. He is still using the p08. I'm starting to think that there is something with the p08 that causes the idle to surge when it's cold outside.

SOHC_2_DOHC

I dont have a P08 on my car, i have a P06 Kenji chipped ECU with a JDM Vtec program and im running a Greddy blue box. Like i said i never had the problem with my last JDM D15b with the same setup but know i do. Its a little fustrating since all this work was done on Saturday, but i only pull a code 3 which is a map sensor can that be the problem????????? HEELLLLLLLLPPPPPPPP!!!!!!!!!!!!!

RC000E

Thermal valve below the throttle body is likely the issue. The white seat inside has screwed itself out, and is creating a vacuum leak essentially. Take the flat side off (opposite the side where the coolant hose is), and screw that seat in all the way, then back it out about two turns.

The point is, that when the car is cold the valve inside isn't seated against the white seat. This allows bypass air, and hence a faster idle when the motor is cold. As the coolant goes in the opposite side, it warms a thermally expansive plug, which pushes the valve on the opposite side against the white seat, and shuts off the bypass air.

If that seat is screwed out, then as the motor warms, and the ecu sees that the ECT sensor is showing warm, yet idle speed is high because the valve can't extend far enough to seat itself, you get the injector shut off/on/off/on syndrome, which creates a fluctuating idle.

Make sure after you screw the white seat in SOME, that you seal the plate that caps it. If that leaks, then you have a new vacuum leak.

SOHC_2_DOHC

Appreciate all the info and im going to give it a try and see if it fixes it. Thanks alot RC00E appreciate it!!!!!! Ill post back after i try it!!!

SOHC_2_DOHC

Adjusted the the screw on the fitv and it settled ok but when on my way back from work i stepped on the gas a little bit to hit some boost and got off the e-way and my idle started to jump again from 1000 to 1500. Then i turned the car off and turned it on again and it didnt jump. By the way no check engine light was on. Im just fustrated and dont know what it is. HEEEEEEEELLLLLLLLPPPPP MEEEE!!!!!!

RC000E

Well, it's likely that you either have another leak somewhere, or you need to screw the white valve seat in further. If it's settling down, but still doing it here and there, it sounds like you may need to screw it in a tad farther to be sure it's closing all the way when the motor is warm.

The other issue could be your tune. In the winter months, with air more dense, you could be running lean, or having something happening in the idle tune. It's pretty common for boosted guys to have pissy idles, and it's just a matter of making some small changes to get it good.

Looking up there I see you have a Greddy kit, so you may be using an FMU. If your are using an FMU, then the tune isn't an issue obviously. If that's the case, then it's still gonna be just bypass air getting through.

My suggestion is warm the motor up to operating temp, pull the charge pipe from the throttle body and put your finger over the LOWER hole on the inside of the throttle body (there are two...an upper and lower). With the motor warm that bottom hole should have no vacuum whatsoever. If it does, then that white valve seat still isn't in far enough, and that's still your vacuum leak. I'd still be checking there, or I'd be checking for a bubble in the coolant or a low coolant level in general.

SOHC_2_DOHC

Ok cool, im going to take the charge piping off and check that, i have a minor tune my buddy had on his car and i imported it to my e-manage Blue box. Thanks again and ill post back and let you know if it worked out.

SOHC_2_DOHC

Ok im begining to think its my Map Sensor because it strats to serge when i get the check engine light and after i shut the car off and turn it back on it begins to surge like a said between 1000-1500 and then when i let the car sit for a little off it doesnt do it anymore. Im going to get a Map Sensor and check it out on Tuesday.

RC000E

Well, a MAP issue can certainly create idle issues. If the ecu's is referencing the wrong load cells, then your going to get alot of fluctuation in air/fuel ratio and things like that.

Step one in fixing anything with these cars, is take the engine light out of the situation. If your kickin a code...fix that, then reassess your situation.

SOHC_2_DOHC

will do thanks!!

SOHC_2_DOHC

Going to get a street tune nothing serious from AMS Performance which they mainly speacialize with EVOs but they do good work, got my appointment on April 1st. Ill post up and let you know how it went.

JaredKaragen

chipped ecu + piggyback.... riiiiiight...

ditch the emanage buddy!

if it has not been tuned or adjusted for your specific car... your problem is there.