Is there any differences? I didn't notice a visual difference between the actual FPRs, but I did notice the h22a FPR has a vacuum line running from it to some sort of vacuum solenoid with a plug on it.

I opted for the h23a FPR because I used my USDM h23a harness and it had no plug for the h22a FPR solenoid. Should I not have done this? If I should go with the JDM h22a FPR+solenoid...how do I wire it up if I'm using a USDM h23a engine harness?

I have noticed that after I rev the car up and let off, or return to idle after driving...it idles very low for a second or two, then goes back to to around 750RPM and stays there until i start driving again...is this related at all? Also...not sure if this is worth mentioning or not, but I'm running an open megan racing downpipe(+header). This could be the cause for some low-end hesitation, but I don't think it'd be enough for a heavy drop at idle like explained above.

Thanks in advance for the tips/suggestions/etc.

 

First question... The H23A uses slightly higher fuel pressure than the USDM H22. So I'm sure that the H22A will have a fuel pressure similar to the USDM H22. As far as the vacuum solenoid, it is not necessary. Just unbolt the FPR from the H22A rail and swap it onto the H23 rail. Just run a vacuum line straight from the intake manifold to the FPR just as it was on the H23.

 

So I will want the lower-pressure jdm h22a FPR on my h22a, rather than the h23a fpr? Also, I am currently using the h23a fuel rail and h22a injectors.

I always thought the jdm h22a had a higher demand for fuel than both the usdm h23a and the usdm h22a, and had higher fuel pressure as well.

 

Well like I said, I only know about the USDM H22... But either way, I'd still use the FPR off of the fuel rail that came with the H22A. At least you know the pressure will be correct for the engine whether it is higher or lower than the H23.

Here is a copy and paste from the factory service manual.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93 Prelude Service Manual &raquo;</TD></TR><TR><TD CLASS="quote">

Pressures should be;
H23A1 engine( USA: Si/Canada SR),
F22A1 engine (S):
(36-43 psi)

H22A1 engine (USA: Si VTEC/Canada: SR-V):
(33-40psi)

(With the fuel pressure regulators vacuum hose disconnected
and pinched)</TD></TR></TABLE>


Modified by no1knows908 at 12:23 AM 5/15/2008

 

Yah, that is a good point you have there. I'll make the switch.

Hopefully this fixes my hesitating/idle problem. That issue could have also been because I accidentally filled with regular unleaded when I should have used premium. I'm accustomed to driving a non-VTEC integra.

 

I would even assume that some of the problems users have had with H22As running rich could be contributed to them not swapping the FPRs. The pressure is not off enough to cause any serious complications but would definitely add to the problem of the already rich factory tune.