i am working on an MPFI swap (my first) for my 1990 base 1.5L. couldnt help but notice the intake i obtained does NOT have any mounting points for the tandem control valve, but has the same 5/8" vacuum port (above the EACV) that, from what i have seen thus far, would typically go to the tandem valve on the back drivers side of the manifold. (seemingly the same valve which is on the back of the DPFI TB which has two 1/8" vacuum lines)

should i just put a plug on the 5/8" port? or is there something else that connects here? not finding any record of this occurance on the internet so far. pulled the intake from a supposed 91 SI (looked kinda like an SI conversion with a half *** wire tuck when i got to it)

 

what is a tandem control valve? I have never seen that part on the MPFI Honda's (which are all I have owned).

 

<p>MPFI doesn't have a tandem valve. &nbsp;DPFI only.</p><p>Tandem valve is&nbsp;the butterfly at the top of the DPFI throttle body as seen in the following pics.</p><p>&nbsp;</p><p><img src="http://cimg3.ibsrv.net/gimg/honda-tech.com-vbulletin/800x600/80-dpfithrottleplate2_37778411d33edbde5330b34e0fe511d 57b7f2351.jpg" title="" /><br /><br />&nbsp;</p><p>&nbsp;</p><p><img src="https://cimg4.ibsrv.net/gimg/honda-tech.com-vbulletin/800x600/80-dpfithrottleplate5_f138ff4492a4b2874360de7466954d7 bbf939dea.jpg" title="" /><br /><br />&nbsp;</p>

 

well that would explain it. the port above the eacv goes to the valve that sits on the back of the manifold with a 2 wire plug on it. that is the fast idle solenoid.

 

every mofi manifold I have ever seen had a mounting point similar to that of an air temps sensor, but with a sensor similar to the one on the back of the DPFI throttle with 2 vacuum lines going into it. Except the mpfi has a single 5/8" line that goes across the manifold to a port above the eacv behind the tb. Or it'll have a 1/8" vacuum line to a direct mounted solenoid like the one on the firewall by the MAP. My manifold has neither, and it is an EGR manifold, stamped pm-8 hf-1 09-10. I absolutely can NOT find any decent record or picture of any Honda or Acura manifold on the Internet with EGR or any of the stamped numbers shown.

 

By the numbers, I believe that intake is from a 92~95 CX D15B8.

 

So then I guess my question is, since my manifold doesn't have the option of a fast idle solenoid, do I just put a plug on the vacuum port above the eacv? Or is there something else to connect to? Will a 91 pm-6 ecu still work without it or do I need a different manifold/ecu?

 

looks to me like the 88-91 CRX HF manifold