j87w

I just swapped a JDM B16A SiR2 into my 97 Civic EX. I used a jumper harness to convert it to OBD1 and it has NO check engine light. When I fire it up its fine it drives great. Then after driving it for say 10 minutes it starts hesitating at lower rpms (Specifically 3000-4500 RPM). When your accelerating it's fine but when you get to speed (say 10% throttle) it starts bogging. It bogs and keeps doing it and starts just misfiring and slowing down. You can get it to stop bogging by giving it like over 1/2 throttle. It just stops bogging, starts accelerating, and its fine. In VTEC it runs great, its fine. I cannot figure this out, as there is no check engine light.
Help me out here guys...

AliasNeo

hmm this happened to me too... i did a little bit of a tune up and changed the fuel filter and that solved my problem... maybe give that a try?

j87w

Ive already changed my plugs. Should I go ahead and do Cap, Rotor and Fuel Filter or Just Fuel Filter...?

jadugartir

cap rotor and fuel filter... I use wix fuel filters from o'reillys but i would definitely go with OEM honda cap and rotor.

these are cheap things which could eliminate your problem, plus they should be done anyway as routine maintenence so even if it doesnt solve the problem youll be glad you did it. run some injector cleaner as well? maybe your new motor has clogged injectors.

j87w

Well they came off my friends 98 Integra. They ran fine on his car. Also NOTE that when first driving it does not do it but the more you drive it the worse it gets. Its only at like 10% throttle at a certain RPM range. Then when you exceed a certain throttle point it just snaps out of it and takes off.

j87w

Also, I noted that when I was searching a few CRX owners with B16's said they get there O2 sensors mixed up. Im not using the EX harness and am a CX harness modded for VTEC. Which O2 plug should I use. Its not throwing a CEL for it, but just to make sure.

amckee

You may want to check for dead spots on your TPS. I've seen them have dead spots and not throw a code. It does not make logical sense that a clogged fuel filter would be your problem. It would only get worse the more the throttle plate opened since the FPR and electric fuel pump are keeping a consistant flow of gas through the filter at all times. Why would WOT have more success that mid throttle if the system was starved for fuel? I have also seen a similar problem at slightly lower RPM when the carbon button in the dist cap is too worn or has a bad spring or is stuck.

j87w

So would that mean a bad TPS? How would I go about checking for dead spots in the TPS?

Anyone else got some ideas...

j87w

Well I changed out the plug wires and distributor cap with no luck. But I realized this. It ran fine until I raced it, I guess you could say. I warmed it up, took it down the highway, and It ran fine. I turned around and gave it some gas this time and then I noticed it started bogging. Also the more gas you give it the worse it does it. Then it hits the "breaking" point and just takes off like normal.

amckee

Did you replace the rotor too?

j87w

No I didnt because I just found that one at my house. Should I go ahead and replace the rotor to?

I noticed last nite that if I dont "race" it at all it doesnt really do it. But when you "race" it thats when it starts. I thought it was kind of odd.

520_Motorsports

have you replaced the fuel filter? found when mine started to bogg out it was the fuel filter!!!

j87w

No I didnt replace the Fuel Filter because

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">It does not make logical sense that a clogged fuel filter would be your problem. It would only get worse the more the throttle plate opened since the FPR and electric fuel pump are keeping a consistant flow of gas through the filter at all times. Why would WOT have more success that mid throttle if the system was starved for fuel?</TD></TR></TABLE>

amckee

Definitely replace the rotor. You want to rule out all things ignition and you should always replace the cap and rotor together. When you go to remove it, see if it feels loose like it might be able to shift around on the shaft. And while your at see how much play is in the shaft.

j87w

Alright, Ill go ahead and replace that to and see what happens.

B16aSir2

Sup dude, I am experiencing the exact same problem as this guy to the t in my CRX. I have the exact same motor swapped but with a 00 head. I have the p30 ecu and obd-I conversion. I started another thread about this because I didn't see this one. OUR PROBLEM IS IDENTICAL! He could not have described it better. You drive the car around fine until you pop vtec hard once then you start experiencing this bogging. Only at 1/4 throttle to half throttle and at certain rpms, then upon giving it more gas it usually opens up. So ******* frustrating because you cannot do any low rpm shifting if you don't want to look like a complete dumbass.

j87w try to unplug your 02 sensor and drive the car around and see how it runs. If it runs better than you have my same problem, and together, we should be able to work through it. I don't think your cap and rotor are going to fix it, I believe I replaced mine and it did not help. It may be something to do with the map sensor setup...Do you have digital camera? Could you post your vacuum map setup? I'll post mine, maybe we can compare. Someone said that it runs much better when the map sensor is located on the throttle body. Injectors may still also be a possibility. We need to figure this **** out though so we can save all the future Sir2 people

puffsef

Ever think about changing the fuel pressure regulator? Definitely change the fuel filter. At wot the ecu is telling the fuel system to dump fuel so therefore it does and it quits hesitating. The bogging is most likely due to a recess in fuel flow ..............Hence a clogged filter, bad fuel pressure riser, etc.................

B16aSir2

Well you know how when you turn the key to the position just before it turns the starter and the fuel pump comes on and fills the fuel rail then shuts off after a couple seconds. Well, my fuel pump doesn't shut off It just keeps pumping fuel through the fuel rail which flows right back into the gas tank. My vehicle is also idling high around 1.5k rpms after I accelerate hard a couple times. I am possibly going to replace fuel injectors today, but I was wondering if my EACV might have something to do with this? The fuel filter was replaced &lt; 10k miles ago and the fuel pressure regulator appears to be functioning correctly.

puffsef

As for the high idle, Your proly not stupid so Ill assume that u checked the idle screw. If thats fine then try adjusting the fast idle valve under the trrottlebody. Maybe that will do somethin to it.

JeffBro

If its only doing it in closed loop its probably not a problem with the fuel system or ignition system. Im thinking o2 sensor or map sensor or tps. TPS is easy to test. If you have a shop manual for your car it will tell you the testing procedure. If not get one. You hook up some test leads and move the throttle to make sure the voltage goes through the proper range. its like 2.5-4.5 or something.

Anyways go get a shop manual and start testing things cause I dont feel like sitting here and telling you all the procedures.

j87w

Yea, I've got a factory service manual for a 95 Integra which will work in this App. also. I set the TPS to .45 at closed throttle and it ran worse. So I adjusted it to where it ran best. Im not sure what voltage that was.

BTW I have changed the rotor and it really doesnt do it anymore. The only thing I noticed is that when your driving at say 3K rpms the tach kind of bounces. You dont really feel it in the car I just noticed that. Then VTEC kicks in at like 6200 or 6100 with a stock JDM B16A ECU. WTF is up with that?

b16greenmachine

replace your primary 02 sensor. had exact same problem.

b16greenmachine

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j87w &raquo;</TD></TR><TR><TD CLASS="quote">BTW I have changed the rotor and it really doesnt do it anymore.</TD></TR></TABLE>

sorry didn't see u fixed it ^^.

j87w

Hey thanks man for chiming in.

B16aSir2

rotor fixed it? come on....That can't be right. I replaced the 02 sensor, no help. The idle adjustment screw doesn't have anything to do with this, and the TPS would never give me a bad read when the car is under no load. In other words, when you are idling and reving, you never experience any hesitation, it is only under load. I am going to do cap n rotor just because, but if it doesn't fix it, and I'm pretty sure it won't, I'll be back to bother you guys again I know the problem is related to a sensor because you don't experience it in open loop. And the map sensor is also fine. You know I love my CRX but if I can't figure out this problem, my dream is gonna die.