nathan.irvin

Hello.

New to the forum not new to cars what so ever. This may be long but I want to give all of the information that I have on hand.

I have a 95 integra LS with a B20B swap. the B18 was burning a lot of oil and finally burnt a valve. I swapped in the B20 and it was running a little strange. I'll try my best to explain it the best I can.
While driving at interstate speed at constant throttle, if you very very very slightly increase throttle at about 1/3 throttle the car would seem to take off. Sensing the O2 sensor was probably ruined by all the oil the B18 burnt I replaced the sensor with a stock replacement Denso unit. The car seemed to lose the take off effect and was running really well and I was happy with the power output. A little surprised actually. It gradually got worse unfortunately, and started to feel sluggish. I decided it was time to find out what was going on with the car.
I Purchased an AEM UEGO (30-4110). I installed it and tapped it into the stock ECU (which I forgot to mention I am using the stock B18B1 ECU) using the instruction at this link:
AEM Wideband O2
When I first started the car it ran terrible and would barely idle. I got it to finally run and took it for a drive. The A/F was all over the place. I drive about 40 miles one way to work so decided I would park it and see what happens on my way to work Monday. Upon first start it struggled a lot but finally got it running. On the way to work the A/F was right in the 14.7 to 15 range while cruising at 70-75 mph. I parked at work and when I came out to leave it started fine. Jumped on the highway and it running really lean at highway speed now with an A/F at 16-17. The car was sluggish and was doing the same thing as with the bad sensor. At 1/3 throttle th A/F ration would dive to 14.7 and seem to take off. If I lift off the throttle a bit the mixture actually gets richer. The only difference is the ambient temp was cooler on the way home. I'm at a loss here. What in the world is going on?

Will a TPS cause this? The TPS has never been changed and the car has 200000 miles on it. I'm hoping you guys can help me out. Timing is perfect. I'm unable to check fuel pressure. I have the filter banjo fitting ordered to install a gauge.

wunfstgsr

No cells? Check the TPS calibrations with a meter but I doubt its that, try cleaning the iacv. Or you could have a bad map sensor.

nathan.irvin

The only faults in the system is for the O2 sensor heater because every Radio Shack in Ohio I think has closed down, so I didnt get the resistor to fool the ECU into thinking the heater circuit was still present. Other than that no. I will check the TPS. I cleaned the IACV when I installed the B18 intake onto the B20. I have an extra map sensor off of the B20 and another one for a B18 incase they arent the same. I will replace it in the morning and check the TPS and see what that does. I appreciate your reply this late.

blackeg

it needs more fuel. the o2 can compensate pretty closely in closed loop, but cold starts and heavy throttle its leeeeaaannn. get a fuel pressure regulator and on a cold start increase the pressure till you get the afr down from the probably 16's it is now to the mid to high 14's. let the bad boy warm up then give it some throttle. adjust the fuel pressure to ensure you see low 13's high 12s. i wouldnt want it running much leaner than like 13.3 at wot. the curves are off a bit between the b20 and ls motors, so between 4500-5500 i think the b20 will have a tad of a leaner spot since the ls map is set for max tq up around 5500 not the 4500 or wherever the b20 make it.

it honestly doesnt matter what number you have for fuel pressure, it matters that you can adjust it to achieve the desired air fuel ratio.


is that a jdm high compression b20b or a 97-98 usdm or low compression b20b? the latter has the dog **** small intake cam which is why it falls on its *** at 5500 rpm. once you get the fuel thing worked out and afr in the safe range swapping that intake cam for the p75 cam that was in your b18b will help it at least not fall off as bad its certainly worth it since you have the parts and dont need to change valvetrain or anything

nathan.irvin

I really appreciate your response. I replaced the MAP sensor today like mentioned above and its still not running right. Here is what throws me off on adjusting the fuel pressure. Keep in mind I am not running a narrow band O2 what so ever anymore. Just the wide band AEM UEGO set on P04 which is 0-1volt. When I am on the interstate I'm seeing high 16s to low 17s a/f at cruise with steady throttle. I have been noticing that im seeing the ratio go to normal 13-15 range when I hit a bump but that just may be my head and its only for a split second and could be because the throttle input is change just slightly due to the bump in the intersate. If i barely blip the throttle it will go normal for just a second but not when slowly rolling into it. If roll into the throttle slowly and steadily at about 1/3 throttle you can hear my (ebay from a previous owner) intake start to whistle (A/F still at 16-17 range) then if just a little more throttle is applied you can watch the UEGO go to 12-14 and you can feel the car take off. If I am at steady throttle and lift just slightly the car bucks a little and you can watch the A/F going all over the place in the 12-15 range.

I've never driven a vtec car but friends of mine are saying it feels like vtec without vtec (just in miniature form). I'm not second guessing you it just doesnt make sense. Seeing that ratio tells me there is plenty of fuel the ECU is just not applying it. It did something similar with a bad O2 sensor. I'm just lost I guess. I do have the blox FPR ordered and will install when it comes in.

The engine is a 96 according to the stamping on the head. Its a P8R head I do believe, but dont quote me on that. Its not the mythical vtec head which i believe is the P4R. I may have them mixed up. Its just the stock head.

Again I appreciate anyone and everyone's input. I just want to get this fixed. I almost took the car to Slow Motion in Sunbury Ohio today and told them to fix it and send me a bill but then looked at my bank account.

nathan.irvin

I dont know if anyone is still reading my long *** post and replies but thought I would update. Going off of what Blackeg said about the fuel pressure I thought I would test that theory. So after leaving work I removed the vacuum line off of the stock fuel pressure regulator. I dont know how much that raises the pressure but the whole ride home at cruise I was in the 15 range rather than 16-17. The car ran dramatically better. I killed the theory about possible bad connection since the gauge was jumping around while going over bumps in the road because when I came to the bad section of highway I took my foot off the pedal and pushed the clutch in. At Idle however the A/F is still around 17. If at cruise going on a slight decline I'm barely on the pedal just to maintain speed. The ratio is everywhere during that event. It goes from 10-17. I'm waiting for the FPR to come and and I'll go from there. Blackeg thank you for getting me thinking about fuel pressure. I know removing the vacuum line doesnt raise the pressure much but it did make a difference.

nathan.irvin

I just re-read your post about the low compression b20. Are you stating that the intake cam in the low comp JDM B20B is the shitty cam and to swap it with my b18 intake cam? I thought the B20 shouldn't be rev'd much past 5500 anyway . Is it safe to rev the B20 as high as the B18?

Caoboy

<p>What is your idle set at?</p><p>Have you cleaned the FITV and made sure it's not sucking in air when it shouldn't be?</p><p>Have you cleaned the IAT?&nbsp;</p><p>When is the last time you've changed the fuel filter?</p><p>Have you cleaned the fuel injectors?&nbsp;</p><p>You keep saying your car is running lean, and you also said you burned a valve on the old motor.&nbsp;</p><p>Do you have emissions testing papers that show what your emissions are looking like?</p>

Caoboy

<p>B18B1 redline is 6800&nbsp;</p><p>B20B low comp is 6500, some are 6700, so 6800 isn't going to kill the engine if you bounce the rev limiter.&nbsp;</p>

nathan.irvin

1.Idles at 750

2.FITV was cleaned during swap in July of this year

3.Intake air temp sensor is new

4.Changed the fuel filter during swap as well

5.Had the injectors cleaned about 6 months before the b18 took a dive. Also run Royal Purple cleaner once a month.

6.The wide band gauge spend more time in the red than it has ever seen yellow. Thats why I'm saying it lean. Please correct me if im incorrect. I have posted the reading i have been seeing under every condition I have put the vehicle through. When I accelerate hard but not WOT the ratio is around 12-13. idling and cruising its 16-17 and tonight with no vacuum on the regulator it was in the 15s.

7.I do not have emissions paper work. We do not have emissions testing here and I have not had it on a dyno to get those numbers.

Caoboy

<p>What is your timing set at?</p><p>I'm assuming your valves are adjusted properly?&nbsp;</p><p>How old is the fuel pump?</p><p>I know the b20 can tend to run lean when using a b18 ecu. Most people I know of who have done the swap tend to get it tuned, using 240cc injectors (from a prelude? or GSR? something factory. I&nbsp;can't remember off hand) to make sure the car is running properly.</p><p>I'm kind of shotgunning the diagnosis, fuel issues with no codes are a PITA though.&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>

nathan.irvin

Don't quote me on the timing but I think it's set at 16. I can recheck that this weekend. Have to borrow a timing light to do it. The fuel pump was replaced with an O'Reilly special about 2 years ago. Valves were adjusted during the swap as well.

blackeg

yeah pretty much. ive taken stock ls's to 7000-7200. i currently have a b20 high comp internally stock and have the limiter at 6900. the pistons are a bit heavier and they use the same connecting rod bolts so its not a bad idea to not rev the **** out of it. not much reason to go above 6800-7000 it makes like no power or tq.

nathan you have to get a narrowband if you are still running an ecu in stock form. im sure the aem wideband has one of the wires coming off of it as a narrowband signal. you can run that wire right into your ecu at d14. check out katman's site it outlines where that is. .:FFS TechNet : OBD1 ECU Pin out Schematics :.

ok now honestly your car is obd1 which is awesome since you likely dont have any issues passing inspection with a tuned ecu. since you have the wideband already it is not a bad idea at all to get tuned. even a decent street tune will do the trick. do not rely on a basemap to get the job done in one shot

nathan.irvin

The link you gave for the pin is exactly how I have the wideband hooked up. The white wire is connected to d14 and I think d22 sensor ground. The Aem wide band emulates a narrow band on setting p04 which I have it set at. I agree with getting a tune as well. $500 dollars for a tune is a hard pill to swallow but I know it needs done.

Thank you for your help.

Garage_Spec

I've been running a stock 99 B20B for the past two years in my 96 integra. I first used the factory OBD2 P75 then later switched to OBD1 P75. I had an issue similar to you but I promise you the ecu isn't the issue. I swapped the FPR for a known good one and that fixed it completely. I now run a B&M FPR just to keep everything set right. Also my B20B bogged at higher RPM with the factory intake setup so I would look into something different if you don't already have one. My car is strictly a track toy and it has no problem revving to the B18b1 settings, it actually feels like the stock power band just with more power everywhere! Happy motoring!

wunfstgsr

Why in the world would you post this here?????

nathan.irvin

I want to thank everyone for their help. Maybe killerkar thinks the full race traction bar or the complete interior will possibly fix my problem. lolol. The FPR is on its way and I will keep you guys updated.

Caoboy

<p>How will a fuel pressure regulator fix the problem? Serious question. Is the old one faulty? I'm assuming that's what you're thinking. How would one test the FPR?&nbsp;</p>

nathan.irvin

What I did last night was took the vacuum line off of the regulator to the injectors are always receiving full pressure all the time. Not ideal but this is just how I did it. The car ran in a much safer a/f range (imo) and had night and day more power.

And not that it's faulty just not outputting what the b20 needs. I'm not the expert here so I may be wrong.

Caoboy

<p>I wonder if there's any difference between the b20 fpr/fuel rail and the b18..I think I threw out the old fuel rail/fpr combo that I had off an older b20 manifold though.&nbsp;</p>

nathan.irvin

I will look this weekend I still have the b20 complete intake. I'll let you know.

tony_2018

The last time I did a b20 swap I recall having to get an adjustable fpr. Totally helped out alot.

wunfstgsr

Helped out in what way please elaborate..

nathan.irvin

Hey guys. Touching base with everyone that helped me. So as you know I have been waiting for the FPR to show up via USPS which as you know is the slowest possible way to ship anything. I think I have caused more damage and possible caused some good as well. So what i have done is adjust the idle screw on the throttle body. I unplugged the IAC and tried adjusting it but there was no change what so ever no matter how many turns. However after driving the idle stays at about 1200. I figure i loosened it too much obviously. I also test my new IAT sensor and it was open circuit. WTF right. Its new. I put in an old one I had around and the B20 is alive. No more vtec feeling. Its smooth as butter and has good power again. I will get the idle screw setting figured out eventually. Just havent had time. No worries about that. The A/F ratio is 14.5-14.8 at highway cruise and richens to 12ish when I'm rowing through gears getting on the highway. I'm happy with it.

I'm still in the 17 to 18 range at idle even on cold start which it has been lean at idle from the beginning. The question is if I increase the fuel pressure wont it richen me across the board or will the computer actually take over and shorten the injector pulse to keep me in the happy engine range at highway cruise? I have sourced a chipped ECU and it will be ordered as soon as my adult responsibilities are taken care of.

Let me know what you guys think. Any help is appreciated.

nathan.irvin

Alright everyone, I finally received the FPR and installed it today. Before I installed it my fuel pressure was just under 40psi. I got the car hot and brought the A/F ratio up to 14.7ish at idle. Now when I drive it just as I was afraid of its rich in my cruise range.
This was definitely not worth doing the swap in my opinion. Ever uses the term you need a tune loosely but the cheapest tuner i'm able to find is $450. Not inconceivable but definitely not what I was expecting.

I have one more question I hope someone can answer. I have followed the instructions that I have found while doing a search for idle mixture screw but I'm still idling at 1200 to 1500 rpm. Anyone have any ideas?