I just purchased a JDM P13 (H22 ECU) and i plugged that sucker in and its seem to idle ok until i drive. Everytime i shift gears it revs high w/o me stepping on the gas pedal. But when i use a P72 (GSR ECU) it runs perfect. What could be the problem?

 

What engine are u running with the P13? If u are running the H22A4, its the injector size problem. The 92-95 Prelude uses 345cc and the 96-01 uses 290cc.

 

I running a JDM H22a 345cc

 

up

 

teh 345cc injectors operate at low pressure compared to the 290cc ones, once you account for the pressure difference the 290 and 345 actually flow the same.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">teh 345cc injectors operate at low pressure compared to the 290cc ones, once you account for the pressure difference the 290 and 345 actually flow the same.</TD></TR></TABLE>

Where is the prove? I dont think what u are saying is correct.

I have first hand experience that the P13 will not idle on 290cc injectors after a few days of driving. Also my friend had the same problem, with 345cc the problem went away.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lude S &raquo;</TD></TR><TR><TD CLASS="quote">Where is the prove? I dont think what u are saying is correct.

I have first hand experience that the P13 will not idle on 290cc injectors after a few days of driving. Also my friend had the same problem, with 345cc the problem went away.</TD></TR></TABLE>

did you swap fpr along with the 290cc injectors into you car from a 97+ prelude? and did you remove the resistor box as well?

if you are running with 290s and the h22a4 fpr they will flow pretty much the same amount as a 345cc with the h22a1 fpr.

 

Im not running 290cc im running a JDM H22A with 345cc's on a bb4.
I mean with the p13 the car idles fine until i start driving it and shifting gears thats when the problem starts.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lude S &raquo;</TD></TR><TR><TD CLASS="quote">Where is the prove? I dont think what u are saying is correct.

I have first hand experience that the P13 will not idle on 290cc injectors after a few days of driving. Also my friend had the same problem, with 345cc the problem went away.</TD></TR></TABLE>
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the proiof is in the factory service manual.
specifications for 97-01 preludes with 290cc injectors state that fuel pressure is 47-54 psi.
for 92-96 the service specification for the h22a1 engine with 345cc injectors state the fuel pressure should be 33-40 psi.

once you do the math to adjust for the different pressures in operation (all injectors are measured at standard flow of 43psi) you will see that both the obd1 and ob2 injectors flow at 305cc to 330cc.

 

i still have this problem. I shift gears and it revs a lil high then it dropps??? AH!!!

 

Any chance that it could be an auto ecu? Just throwing out ideas.

Mike

 

nope its a 5 speed manual