Hi, I used to be turbo'd now I reverted back to stock on my 2000 civic si. I have the stock ECU in there, but since I have lower compression pistons (9.4:1) it doesnt pull enough vacuum at idle so the ECU is confused and dumps too much fuel, causing my code 45 to pop up. How can I get it to pull a little more vacuum so it can run right. It pulls about 16 inches right now, so I just need about 2 more inches. Thanks!

 

Put the stock pistons back in .... Why did you go back to stock?

 

Can't a cheap used AFC or an SMC do exactly what you want?

You could try to grow some carbon build up on your pistons...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mos &raquo;</TD></TR><TR><TD CLASS="quote">
You could try to grow some carbon build up on your pistons... </TD></TR></TABLE>

LOL

 

the compression of your pistons have anything to do with it. my car pulls 20-22in of vacuum and its 9:1. your car is idling kinda rough because of too much fuel or lack of fuel and it will cause shitty vacuum. hence the code 45 (system to lean or rich).
i dont know if u have anything to adjust your fuel but it sounds like it needs some adjusting

 

Have you checked for a vacuum leak?

 

retune.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo E 604 &raquo;</TD></TR><TR><TD CLASS="quote">retune.</TD></TR></TABLE>
retune what? he has a stock ecu, doesn't he?

 

do u have an after market pump in there? that could cause your fuel pressure to rise quite a bit making your car run too rich

 

did u put yoru stock injectors back in

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by u2civic1 &raquo;</TD></TR><TR><TD CLASS="quote">did u put yoru stock injectors back in </TD></TR></TABLE>

I was going to ask that too

 

you have something else wrong...... i have tuned cars with as low as 7.8:1 and they pulled vacuum just fine.

 

i have stock ecu, stock injectors, stock fuel pump. car is running rich. I dont know what else could cause that. i replaced o2 sensors, had the electrical system check out by a mechanic, everything checked out fine.

 

bump

 

up

 

Could be cam timing. Change your belt lately??