prelude9999

ok, i switched out a chipped p28 for an unchipped p13 today (i want to pass emissions, so this is my first step)

it started without any problem, was idling fine and after it warmed up for a few minutes i merged onto the freeway and VTEC kicked in nicely at 5500 RPM (it seemed to kick in harder than with a p28)

and then after a few more minutes, off the freeway, it starts idling weird, it jumps from 1000 to 2000 rpm and back, any ideas on why?

not sure if you need this info but right now the egr valve is there but the vacuum tube from it goes nowhere (it should go to the EGR control solenoid), plus the EVAP canister is not there and the lines for that on the throttle body are capped off, one more thing i have walbro 255lph fuel pump and a stock regulator

ITRekhatch

you just answered ur own question man, u have a erious vacuum leak.

prelude9999

but it ran and idled fine with the p28, so a vacuum leak doesn't make sense, i tried plugging the vaccuum line from the egr valve, and it made no difference in the idle

also, now i am throwing codes 12 and 36
the 12 is because i don;t have the egr control solenoid hooked up and the 36 is because the ecu has 4 plugs and i only put in 3, and i think the fourth was for some auto traction device, i think this ecu may have been for an auto H22

anyone else have any ideas?

prelude9999

just reset the ecu, and i still have a weird idle, now it idles at 1000 rpm then slowly goes up to 1400 and then back down quickly to 1000

Jason kiDD

Definately a vacumn or improper vacum issue.

prelude9999

what do i do to fix that? how do i diagnose a vacuum leak?

and why did it idle fine before i put in the p13 ecu? is it because the egr isn't working (because i have no egr control solenoid)

Turbogixxer

You have a idle vavle that goes in line between the FPR and the IM vacuum line. That why it happen with the P13 and not the P28. You need to wire it up for it to the ECU.

Jason kiDD

Assuming that all the wiring is correct then it shouldnt matter which ECU he plugs in as long as either is ODB I. Wires are the same..

prelude9999

idle valve? what is that? am i missing a valve that is causing it to idle weird?

v4lu3s

the little valve between the fpr and manifold is taken off of every swap i do since it doesnt do anything cept get in teh way. if you want to find a vacuum leak id get a can of carb cleanber and spray around the manifold il the engine bogs, once it bogs you know you foudn where hte leak is.

Turbogixxer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">the little valve between the fpr and manifold is taken off of every swap i do since it doesnt do anything cept get in teh way.</TD></TR></TABLE>

Not true. If you do not run it, you will have surge problems with the P13. I have seen it. BUT, this is assuming that nothing is wrong with the car.

prelude9999

i looked for this idle valve and didn't see it, here is a pic of the fpr and line to the manifold: (am i looking in the right place?)



does anyone have a pic of this valve? is it a dealer item?

prelude9999

here is another pic of a stock 2000 prelude H22, can you see the idle air control valve in this picture so i know where it is?

prelude9999

here is a closer shot of the previous picture:

v4lu3s

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbogixxer &raquo;</TD></TR><TR><TD CLASS="quote">Not true. If you do not run it, you will have surge problems with the P13. I have seen it. BUT, this is assuming that nothing is wrong with the car. </TD></TR></TABLE>


how does fuel pressure cause surging idle? and why dont american preludes require it? and why do the last 6 jdm h22a's i ahve dealt with not use it and not have problems?
that doesnt make sense to me. finally....what ecu pinout is it supposd to go to if it is so important?

prelude9999

after looking at my picture of the engine, it looks like the IACV is right below where you adjust the throttle cable, am i right? at this time, i'm not sure if it is wired to the ecu or not, i'll check that tonight

turbogixxer, do you know the wiring for this? i saw on your ecu pinout thread, A9 (blk/blu wire) is for the IACV, are there any other wires?

prelude9999

tonight i tried disconnecting the plug to the IACV and it seemed to idle fine, but then i through a code 14 (for not having the IACV hooked up), i don't want codes thrown so i would like to fix this, there is a wire connected to A9 (for the IACV) on the ECU

in the manual it says you can use a test harness (which i don't have) to see if the IACV is working by jumping a wire between A9 and A26 (a ground),

here is my question:

can i safely try this (without screwing up the ecu or anything else): take out the "A" plug from the ecu, run a wire between A9 and A26, turn the ignition to on, and see if i get a click from the IACV

prelude9999

does anyone know the above question???

Turbogixxer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelude9999 &raquo;</TD></TR><TR><TD CLASS="quote">in the manual it says you can use a test harness (which i don't have) to see if the IACV is working by jumping a wire between A9 and A26 (a ground),</TD></TR></TABLE>

A9-IACV IAC valve Blk/Blu, About 10v KOEO on Warm engine
A26-LG1 gound Blk/red, less than 1V

I will look more in to it about that. I will try to get a flow chart for IACV for you.

fastwanabe

you might want to look into the FIV..... Fast Idle Valve. It sits underneath your throttlebody and has a small cap on the back held shut by 2 8mm bolts. If you were to open it you will see a small nylon screw, all you have to do is take a small flathead screwdiver and screw it all the way in. It solved all of my idle issues.

Turbogixxer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">how does fuel pressure cause surging idle </TD></TR></TABLE>

How does it not? Saying that fuel pressure can not cause surge is wrong. You can control RPM by fuel pressure.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote"> and why do the last 6 jdm h22a's i ahve dealt with not use it and not have problems?</TD></TR></TABLE>

ALL the ones that I have seen had it. They all had the same surge porblem.

Answer this, Why did it change when he just changed the ECU? It is not EGR, I have wire it up without a CEL and it have the same surge.