Jumpy idle after I swap my H23A 4ws to a f22b engine. - Honda Prelude Forum

92Lude4WS · 07-01-2004, 04:40 PM

Hi Guys,

My mechanic said the problem could be the ecu because of my 4WS. They also try to swap the f22b ecu but it was worst so they put back my original H23A 4ws ecu. He told me to get the f22b 4ws ecu to correct this problem. Is there such an ecu for that? I called the shop where I got the ecu and they said that they will look for it from Japan. Does anybody experience this situation before? Is there something that I can check on. I do notice one thing weird was that my original stereo anti-def code doesn't work after this engine swap.

Thanks in advance,

tenzola · 07-01-2004, 04:48 PM

it's not your ecu... because all the "si" ecu's are the same

the 4ws ecu is actually located in the trunk and has nothing to do with the idle

surging idle is usually becuase of a vacumm line.. i know mine was

i'm still having a little issue with it.. but if you adjust the throttle cable a lil bit to have the idle around 850-950.. that should cure the problem.. not good for gas.. but even the lowest idle is around 700.. maybe 650

you might also want to check for air in the coolant system.. i forgot if this could be a cause or not.. but after you do a swap.. there is usually a bit of air still in the system

so check vacumm lines, throttle cable, coolant, and lastly.. or maybe it should have been first.. the idle control valve located i believe near the throtle body butterfly valve

92Lude4WS · 07-01-2004, 05:22 PM

I'll look into those things. How do you check for air in the coolant? I am not sure where the idle control valve is but I am sure I can find it. Oh, another thing is that the idle is worst when I throw in reverse. It's good when I put in park but jumpy when in drive/reverse (auto transmission).

Thanks,

tenzola · 07-02-2004, 07:30 AM

the air in the coolant can be done a couple of ways.. when engine is cool, take off the rad. cap and see if it's filled... if it's not mix a 60/40 coolant to water mix untill it's full.. start the car and wait with the heater on max and all the way hot... let the car run for about 5 minutes on idle and the bubbles should all come out... turn off the car.. put the cap back on.. fill the overflow resevior with coolant past the "max" line.. drive the car for about 20 minutes on the highway and when you get back.. turn off the car.. check the overflow.. do not take off the rad. cap.. burning coolant will blow out of the radiator.. just check to see if the overflow went up or down.. that should take care of the air in the coolant

something i would suggust doing is having the trans fluid either drained and filled 2 times or just go to a trans shop that have those super flush where they take all the old fluid out and put in new fluid <--- the person i got the car from never did this and the fluid looked like gray paint... it should be a clear red

hope this helps.. i know it can be fustrating but hang in there.. when everything turns out good.... you'll feel a sense of reward like no other

92Lude4WS · 07-02-2004, 10:20 AM

Thanks Tenzola. I'll give it a try.

NoShoNoGoAccord · 07-02-2004, 12:43 PM

Yup, sounds like a vacuum leak. It has nothing to do with your 4WS, that's for sure.

tenzola · 07-02-2004, 04:27 PM

anytime man... that's what po.com is for

hell... on my first build i spent 3 weeks trying to figure out what was wrong with the car.. engine was fine but car didn't move... after freezing over and over.. it turned out to be a half shaft issue

my second build was the engine.. kept on crancking and never got it to fire.. after 2 weeks of doing everything from the main relay, new plugs, new wires, new cap and rotor.. it turned out to be that my distributor shaft was turned 180 degrees the wrong way... i even siphaned out 5 gallons of gas

92Lude4WS · 07-03-2004, 02:35 AM

I didn't know that a engine swap can have so much problem. I hope I can fix the problem soon. It's getting annoying.

Thanks,

OSOFAST10 · 07-04-2004, 01:39 AM

check your PM i pmed your answer

92Lude4WS · 07-04-2004, 02:53 AM

You mention air sensor at the tb in my pm. I am not familiar with tb, what is that short for? Are you saying that I am missing that or do I just need to replace that? It doesn't exist in my current engine?

thank,

92Lude4WS · 07-06-2004, 05:56 PM

I am not sure what I did. All I did was re-check all the vacuum hose but I am not sure that any of it was loose in the first case. But after doing that I started my engine. For some reason, it's idling o.k. now at around 700-800 rpm at all the gears including reverse. It's very stable now. I am not sure that I tighten the vacuum hose because I didn't felt or hear any click or the problem solve itself when computer re-adjust to the new engine. Another thing that suprise me was that my anti-theft radio also work when I punch in my code. It didn't work before when I enter it for the last 30 times but it work right after my engine idle work. Anyway, Thanks for everybody's response especially tenzola. Just to clarify, I used my original H23a 4ws ecu. The f22b ecu was very unstable.

Another issue I had with the JDM f22b engine was that it leak a little coolant water under the engine. When I told my mechanic that he said that the JDM engine was different from the USDM engine because there's more hose than our USDM. He was trying to seal it. Even when I don't turn on the air condition, there's always a little coolant water leaking. He said it shouldn't be a problem but they look at it soon and try to seal it. Other than that, the engine drive just fine. Almost as strong as my original engine but for the price you pay for it, it's worth it.

Thanks a lot.