Motor Bogging

[spoonSiR2]

I recently put a new P72 ecu in my car and now when I get on it my car will bog for a couple of seconds and then it will accelerate as normal. I had a chipped P28 ecu running my car before and I never had any problem like this. If anyone has any ideas as to what is causing this I would appreciate hearing your input.

[sassage]

what motor are you running?
p72 is a gsr chip so if you dont have a gsr, or have one without the Dual runner IM, it's probably causing it to go into limp mode cause the gsr intake isnt present

[KruciaL7integra]

what are you running that P72 with...if it's a B16 thats not a good idea

[CRVTEC0WNZJ00]

Yep...need to know what engine your running if your running a GSR ECU its probably looking for the butterfly valves which don't exist in the B16A IM or the ITR IM.

[Girl]

Looking at his Profile... Seems like he has a Civic with a B18c in it.

[CRVTEC0WNZJ00]

Hmmmm...I see that...I dunno what to say then...start running the chipped P28 ECU...wait...do you have Skunk2 IM on your car if you do that manifold doesn't have the butterflys and thats probably whats gayed in your engine....need more details to assess the problem.

[spoonSiR2]

yeah, I have a B18C with the skunk2 intake manifold. I don't have any check engine lights and I don't think the intake manifold should make much difference because I used to run the stock intake manifold with the butterflies constantly open becuase of the P28 ecu.

[CRVTEC0WNZJ00]

Why did you switch from a chipped P28 if it was running fine...that makes no sense to me.

[spoonSiR2]

Originally Posted by CGCivicSiT

Why did you switch from a chipped P28 if it was running fine...that makes no sense to me.

I had a thread on here a couple of days ago where you said the same thing. It might not make sense, but I need to run the P72. In order to make my swap "legal", I need to run the computer that initially came with the motor. It makes sense if you are familiar with the California BARR requirements. Even if it doesn't make sense, are there any ideas out there as why my car bogs in the low end?

[CRVTEC0WNZJ00]

Oh sorry man, totally forgot, but I have bad drain bammage...I'm not sure why it would be bogging in the lower RPM's besides the IM thing but you don't think thats the problem...do you have a CEL on? Personally what I would do if I was you...I'd put the P72 in, go get the smog and everything passed get home and put hte P28 back in or your second choice is to take it to a local mechanic, because I can't see it, hear it, and don't really have enough info to figure it out from here. sorry

[JAYMAN320]

Just because you have a ECU that is designed for a dual Im doesnt mean it will bog out the motor....I had a GS-R with the skunk 2 single runner IM ...no bogs whatsoever. NO modification needed for the ECU aswell, it just send a signal but with no action.


Any CEL's? try using another ECU...but the same model....see if the problem persists. Vacuum leak? Tune up? Fried circuit in the ECU?

[meconfu5ed]

Originally Posted by JAYMAN320

Just because you have a ECU that is designed for a dual Im doesnt mean it will bog out the motor....I had a GS-R with the skunk 2 single runner IM ...no bogs whatsoever. NO modification needed for the ECU aswell, it just send a signal but with no action.


Any CEL's? try using another ECU...but the same model....see if the problem persists. Vacuum leak? Tune up? Fried circuit in the ECU?

There is no way the cars power curve was at maximun potential without tuning if you went to a single stage intake on a P72 ECU without tuning. Engine breathing is crucial to creating power and putting on the IM drastically changes the breathing of the engine in a way the P72 could not compensate for. If you dynoed the car you should see two power humps before tuning.

[JAYMAN320]

Originally Posted by meconfu5ed

. If you dynoed the car you should see two power humps before tuning.

You would only see two humps if it were on a gs-r.....The VTEC X-over and the secondaries opening due to the IM. Of course you would see two humps...its only obvious. You would only see one hump with his current setup.

When I had my gs-r dynoed you would see two humps....

When I changed the dual IM to a single runner the dyno charts showed little lost. Why? Because the ECU compensates for the new reading from various sensors.

Originally Posted by meconfu5ed

There is no way the cars power curve was at maximun potential without tuning if you went to a single stage intake on a P72 ECU without tuning.

Of course it wouldnt be maximized. Because it wasnt tuned for that kind of a setup. I never stated that hp would be maximized, only that with my personal experinces I have witnessed no loss of power down low, or bogs. The p72 with a single runner IM would show no bogs down-low because the ECU can compensate from the additional airflow. Let me find my old dyno charts and see the BEFORE and AFTER results



Here is something that I found awhile ago when I was shopping for my skunk2

Originally Posted by spponSiR2

had a thread on here a couple of days ago where you said the same thing. It might not make sense, but I need to run the P72. In order to make my swap "legal", I need to run the computer that initially came with the motor. It makes sense if you are familiar with the California BARR requirements. Even if it doesn't make sense, are there any ideas out there as why my car bogs in the low end?
04-03-2004 05:00 PM

As said on http://www.hondata.com/ecus.html

"The IAB or secondary intake runner is a set of butterflies in the intake manifold of B18C and H22A engines. The P72 ECU controls the IAB, but other ECUs do not. If IAB control is lost by swapping ECUs then the engine will always run on the shorter intake runners, typically losing 8 hp from 3,000 to 5,500 rpm."

[meconfu5ed]

I thought he was running a GSRs B18C1 in his car? What's he running?

my point is- this guy has a car- has modified it- doesn't have it tuned to the ecu and wants to know why things arenn't right with the car. Tune it- come back and ask for help. On the other hand... can't you roll through certification with the P72 and swap it back when you get home?

[spoonSiR2]

Originally Posted by meconfu5ed

I thought he was running a GSRs B18C1 in his car? On the other hand... can't you roll through certification with the P72 and swap it back when you get home?

Yes...this is exactly what I am doing, however I only asked my original question to see if anyone could point to anything that was seriously wrong. As soon as the inspection is over my car will go back to the way it was and run fine.

By the way, my motor is a B18C from a JDM Integra SiRG so it has an intake manifold just like the USDM gsr intake manifold