So I've searched around in here and other spots on the net and I haven't found a solution to this issue.

I just swapped a D15B JDM engine into my 91 CRX Si. Used rywire, etc bla bla for the swap. Basically, after some idle air control valve issues it seems to have gotten smother and everything is dandy. The one problem that remains is that it feels like when I take off I'm missing some power. This thing pulls pretty well but sometimes more than others the engine up to about 2500 rpm feels like its missing or just basically running like crap.

I have two areas that I have yet to check, idle speed setting and timing. I adjusted the idle speed when the IACV was being all wonky and I may have not adjusted it correctly. Someone was saying about how you have to pull the plug on the IACV before you adjust idle but I cannot confirm that yet. The other issues may be with the timing. I put a light on it and adjusted the dizzy to get it right but I had to go to the extreme on way with the dizzy in order to get the mark to line up. I might have the belt a tooth off.

Other than those two explanations can anyone give me an idea why this thing is crap until I get the revs above 2500? It seems semi random and I can't recall if it is when I get on it or if it is whenever. Any help will be met with many thanks!

Mike

Oh - No CELs are being thrown. I have never seen any issues from ECU, but I can say I would hardly be able to identify any if there were.

 

"D15B non VTEC FI 108 HP (OBD1)
D15B VTEC 130 HP (OBD1"

I found that floating around somewhere... if you have the non vtec motor, chances are the .1 liter difference in displacement is causing a loss of torque

 

i have seen if you use the obd0 distributor with the obd1 motor it runs like ****
i prefer swaping to obd1 ecu and distributor should take care of problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IT GUY &raquo;</TD></TR><TR><TD CLASS="quote">"D15B non VTEC FI 108 HP (OBD1)
D15B VTEC 130 HP (OBD1"

I found that floating around somewhere... if you have the non vtec motor, chances are the .1 liter difference in displacement is causing a loss of torque</TD></TR></TABLE>

Theres no displacement difference between those two engines you just listed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~sp33~ &raquo;</TD></TR><TR><TD CLASS="quote">

Theres no displacement difference between those two engines you just listed.</TD></TR></TABLE>

but there is from a d16a6 his crx si originally came with and the d15b he just swapped in...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mikejr83 &raquo;</TD></TR><TR><TD CLASS="quote">I just swapped a D15B JDM engine into my 91 CRX Si. .</TD></TR></TABLE>

sorry if it wasn't clear enough the first time I said it

 

to answer your question yes i believe you do have to unplug the iacv when setting the idle screw. And if your timing is a tooth off that would definetely affect performance. My sohc zc was a couple teeth advanced and it would slug up to about 3500 rpms and then after that it would pull like a bat outta hell.

 

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

but there is from a d16a6 his crx si originally came with and the d15b he just swapped in...

sorry if it wasn't clear enough the first time I said it</TD></TR></TABLE>

No probs, i thought you were comparing the two engines you listed. My mistake

 

Sorry, bout no reply. Craptastic work is keeping me down. Well... I went back and more critically looked at the problem. When I originally posted I was frustrated as heck trying to fiddle with stuff to make things better...

Anyhow, the original 1.6 was blown up before I got the car. Some genius decided to take his 1.5 block out of his '95 Civic and use the 1.6 head and intake to keep the car running. Let me tell you, there was major wiring issues all around. That is one of the large reasons for me doing this swap. So, I put in a p08 ecu and it should be a obd1 dizzy as it's the one that came with the engine. It had some slight bearing issues, but nothing I would consider bad. I put on a new rotor and cap.

When I put this thing in the car I had some rough idling issues. The car had a firewall map sensor that I thought would be the problem as the new tb had a top mounted one, which I plugged with a rubber dealie. I checked all my vacumme lines and still had a rough idle at about 800rpm, where I think its supposed to be (right?). So I disconnect that map and put another one in the tb and still do not have satisfactory idle.

The engine from the get go was doing the up and down rpm deal like a bad lacv. So after cleaning like three different ones out I got one that would work like 90% of the time (90% of the time at idle it would go nuts). But a current problem still exists, something that I believe has to do with the loss of performance. At under 1K rpm it has a rough idle. It is almost like it is missing or something, but not as bad.

I've tried doing the plug wires and I've checked the plugs. The gap seems darn close. I didn't get a chance to do the timing belt this weekend so I'm gonna have to get it right next weekend. My major issue is that I've hit it with a timing light and moved the dizzy around to where I think the marks line up.

landavis90, hopefully it is the same. Cause it sounds similar. I get to about 3500 and it sets me back in the seat. I still can't tell if VTEC is engaging, but it does seem like at that rpm it has more ***** than the old POS motor that was in there!

Thanks for your help so far. If you have any other input let me know. I'm busy throughout the week, but if I can I'm going to pull the timing belt and realign the marks.

Thanks!

Mike