I have an OBD1 prelude and I just installed an OBD1 P72 in it. I reseted the ECU and start the car. The car starts but has a weird sounding idle and CEL.

I jump the service connector, No luv
No CEL light flashing so I dont know what is wrong wit it.

So I put the P13 back, she is back to normal now.

So do I have to do anything else to get the P72 to run it my car?
I want to sell the P13 and drive the car to the hondata tuner with the P72......

 

it's plug and play but you'll be running super lean...BAD IDEA

 

I second that....mines hooked up to hondata..that would be the way to go..

 

I only need it to drive down to the tuner so no biggie. I wont be redlining or something like that.

Does anybody know if this an OBD1 or maybe its OBD2 P72.......

37820-P72-C01
814-100552

 

yup, I am heading that way

Another thing, the ECU is already socketed for hondata or tecktom and the jumper for the switch is still in place. So does that mean it is runnin off the stock program or the 3rd party (which is nothin)? Maby thats what is causing the CEL

 

plug and play. But you might not be running as lean as you think.

I've never seen stock dyno graphs on this, so DO NOT TAKE IT AS FACT.

Just a thought.... ok? One possibility..... NOTHING MORE THAN THINKING OUT LOUD!

The p72 is programmed for smaller injectors. You just hooked up an ECU that thinks it's pushing enough pressure through for 240cc injectors, but you're running 330cc's. It's possible that it's rich, not lean.

Probably not the case. When I hooked up a P72 to mine, it ran fine. Had an odd power dip before VTEC, but when 4800 hit, it jumped.

 

I have seen a dyno chart on importreview.com that had a comparison of the P13 and P72 on a h22. The P72 ripped *** on the top end but falls flat on its face at the crossover. Too bad they didnt post the A/F graph....

Anyway, how come the P72 works for everybody except for me
I just went back outside and tried it again, ****** CEL...arrrghhhh
WTF?????

 

I have seen the dyno with a/f it's liek 14-15

 

i agree, i think theyre are differnces, but I ran a Stock P72 in my car for like 3 months and it ran fine, if your not comfortable doing it then dont, but it ran absolutely fine, it never leaned out..my a/f guage always read green at WOT... there was also no pinging or anything whatsoever...half the people think its a bad idea, and the other half like it..mine ran much better with the p72, and as a matter of fact now im running a P28 chipped with a P72 Mugen program..runs perfect...peace

 

So according to your A/F meter, it is safe to run the P72 at WOT?

 

Running an ECU with fuel and timing maps made for a completely different motor without any idea of EXACTLY what they are is stupid.
Anyone who would just plug a P72 into a prelude and go put it on the dyno is a complete idiot.
It's possible the timing maps are similar, and the short term fuel trim will be able to compensate for the differences in fuel maps and injector size, but I wouldn't take that chance.....
Brian

 

like i said people can do as they wish, when my motor was hooked up to a wideband O2.and run on the stock p72. it was never "leaned" out..the feul was acceptable..but again i guess every car is different..peace

 

I tried it for a weekend and didnt like the lag due to the earlier change over. VAFC and the P13 for me!

 

Here is the visual of the lag that you are talking about courtesy of importreview.

Oh yeah, red is P72, blue is P13




[Modified by Tru_Playah, 9:54 PM 4/2/2003]

 

Can this "lag" be evenedout with a Hondata S200? And a VAFC?

 

Hondata = Yes
VAFC = No

 

you may be able to improve it by raisingnthe VTEC point...It's my suspicion that since GS-R secondaries open really late there isn't enough air.

I'll find that dyno I was talking about

 

Cool, I have both and a P72. Thanks

 

So I just got the P72 in my prelude running now.

I have to say that WOT does feel weird, not uncomfortable but different.
Vtec kicks in like at 4500 rpms and the it kind of just crusies till about 6000 rpms. After that it takes off like a raped ape

Hey, did you guys drill the extra holes to secure the GSR ECU to ground or did you just leave it liek that......

 

on that dyno graph, vtec set at about 4300 would be a lot better for taht car.

 

your car lags till 6000 cuz your secondaries arent opening up till then, unplug them so theyre open all the time, and it will pull from 4700..all the way up...there ya go...peace

 

Then i would have save some cash and just got the P28

 

so if i use a p72 on my prelude the secondairs will take longer to open and wont open until 6000 instead of the normal 5000 RPMs?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">so if i use a p72 on my prelude the secondairs will take longer to open and wont open until 6000 instead of the normal 5000 RPMs?</TD></TR></TABLE>

i have heard this from more then one person, the gsr has a different intake mani, head, block, ect, seems only natural that the IAB would open at a different time.

Joel started a thread on this a while back, i dug it up https://honda-tech.com/zerothread?id=612831

-Dustin

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">so if i use a p72 on my prelude the secondairs will take longer to open and wont open until 6000 instead of the normal 5000 RPMs?</TD></TR></TABLE>

yes...your supposed to be able to change this in the hondata but mine wont let you. so i have it hooked up to vacume, closed during part thorttle, open when floored...works good since im boosted