Lude Generation

Hello everybody!

I have a question about the value of the MAP sensor at idle on a H22 engine, to be more precise it is an H22A7 .
Could you tell me how many mbar do you have at idle and with how much rpm ( idle value) ?
Thanks a lot for reading me!

So nobody here has tuned his H22 by himself?

So actually, i'm near 256mBar at 1000 rpm ( yes my idle is too high and i want to low it down ), i'm in doubt of any vaccum leak, so if somebody has any number to compare with mine, it would help me

My engine specs:

OEM airbox with a 64mm throttle body and a K&N clean filter panel
H22A7 with oem camshafts, EGR deleted
Oem exhaust manifold , decat and "BlueFlamme" exhaust system.

Tuning system ( i believe it doesn't really matters ... P75 ECU, vtec converted, PA sensor momentary diasabled, Neptune RTP with DemonII daughterboard.)

Thanks for your help and thanks a lot for reading me

what are you trying to do??? testing a map sensor ? that is done with voltage not milibars

Does it not give the correct standard values in the service manual?

Thanks for the answers!

What i'm trying to do is to compare the vaccum value i have with another engine in way to be sure that i don't have any vaccum leak. For that, i need to compare the value with an engine as similar as possible with mine.

So i read this value via the datalogging tool of my engine management system, it is not a voltage value but the value in millibars. I've tried 3 different MAP sensors and i have the same values so i can suppose that the value readed is good.

About the service manual, no there's no "standard" value at idle, unfortunatly

Only the people who have an engine management system with dataloging could answer to this kind of question

I have a stupid question, if i write "vacuum at idle" instead of "vaccum at idle", does it change something about the comprehension of my question ?

I'm sorry, i rarely use translators when i write in English, and i know i surely better do , so maybe when it is clear for me in fact it isn't !

So, to clarify , when i read the value of the MAP sensor at idle, it indicates nearly 256 mbar at 1000 rpm , so if somebody could tell me how much vacuum he can read at idle on it's H22A7, it will help me!

Thanks a lot!

Look at page 290 (section 11-58) of the 5th gen service manual. Use the one with the links http://www.ludegeneration.co.uk/wiki/in ... ce_Manuals

There is a flow diagram that states the approximate voltage / gauge reading needed (101 kPa / 760mmHg / 30 in.Hg)

Thanks for the answer Merlin.

I already have this diagram in my workshop manual, but it isn't the information that i need.

I need to know how much mbar/kPa/inHg does normally produce an H22A7 at idle...

For example: if i connect an vaccum gauge to my manifold when the engine is idling, how many mbar/kPa/inHg will i read on my gauge?

Once again, thanks a lot for trying helping me, the language barrier doesn't help so please be patient with me

I would assume the H22a7 will be the same as the other 5th gen H22s so it will need to be approximately 101 kPa / 760mmHg / 30 in.Hg as stated in the 5th gen service manual.

Thank you Merlin , i have already read these pages but the answer is not exactly what i search...


As you could see in this picture, for example at 1516 rpm, the value given by the MAP sensor is 256mBar, so it doesnt' match at all with the value given by the workshop...



Here's a picture of a Crome basemap, so you can see that, for example, at idle the vaccum is somewhere between 114mbar and 403 mbar



So it is impossible to have at idle a vaccum near 101 kPa...

About the comparaison between H22A7 and others H serie engines, the vaccum at idle dépends for a great part of the camshafts that are in the engine

So, Merlin, i have read that your engine have been remapped on Hondata S300, do you have the possibility to connect a laptop to your EMS system and read directly the vaccum value at idle?


I have to add that i have read a lot of pages here about nice Prelude and your prelude race car is very nice, hope you have a lot of fun with it!