I have a b20vtec (bought that way) p61 obd1 ecu. It runs really rich till about 3500+ rpm then still rich but goes to optimal after 3000. I'm swapping in a freshly rebuilt b18c5 and need to know if I can drive 25km to the tuner shop get it tuned. And how should I go about breaking in the new motor. It's got cp pistons arp bolts and head studs and eagle rods. Thanks

 

How rich is really rich?

 

Sounds like a question for the one that will be tuning your car. Or if your computer is chipped just have one burned with a stock b18c5 map to break motor in and get to tuner.

 

Well it's just a glow shift gauge(non digital) so it just shows green for rich and it's always green but after 3500 it goes into orange (optimal) but still green.

 

That sounds like what I might do. I talk on the phone with the two tuners around here and they both just said dont drive it hard. And I haven't been lately cuz 5000rpm is my vtec and my valve cover and vtec silinod is leaking a bit of oil. So I've been keeping it outta vtec. Most of the time. This weekend I did it 5-6 times seemed ok not leaking or burning much oil.

 

Hmmm... I get the feeling you're getting this information from your stock narrowband sensor. If that's the case, it's pretty much meaningless.

 

He is right get yourself a good wideband. Depending on your tuning software you can even wire its output up for data loging

 

Hey ya I was thinking of picking up a aem UEGO it's used but like new only 100$ so I dunno if I should or not. I think I might as well for the price. Thanks

 

Do it. You're just pissing in the wind without one.

 

Lol hahaha ok I will get one for sure. The motors not in yet so I still got a lol time. Thanks alot spadam for keeping me posted thru this . I've been learning off h-t and b20vtec for a few years now. But have been doing alot of it on my own lately so finally singed up so I could get the info I need not just same kinda problem this guys having. Now I can ask w.e. I try and research first always So thanks alot

 

Hey so I just installed the AEM UEGO (30-4100 I think) lastnight and it's over 17.9 on there at idle and some pointes of driving. It goes into unreadable 17.9+ and shows --- but when I step on it it goes all over 13.? - 16.? if I'm driving half throttle or almost full it like that seems ok but all over still. But when idle it's 17.9+ --- so I dunno if it really bad tune before or what's up

 

The car should be running like dog **** at 17.9. Did you hook everything up correctly? Do you have or have access to a fuel pressure gauge?

 

Well I been driving the car for almost a year seems good. It just burns lots of gas. 350km a tank mostly. Revs up and down 1000rpm to 16-1700 at idle then sometimes stops. There's a regulator cuz it's a b20vtec. When I step on it it's 13.6-15.2. Fluctuates alot.

 

Yeah it's just the 6pin sensor and 4pin power wire and signle wire. Power from fuse box ign pin and grounded behind the kick panel and ran the signle wire to D14 just spliced/tapped into it on the conversation harness. Since the old 02 is unplugged. There's a gauge on the fuel filter. Thanks

 

What tuning platform are you running? Are you datalogging, or just using the gauge? There are a couple of reasons why (typically) you can't just connect a wideband's output to D14. If you're not logging and the car is not running closed loop, there's no point anyway.

When you say it's grounded behind the kick panel, do you mean to one of the ecu grounds, or have you just grounded it to the body somewhere? It really needs to be in the same ground plane as the block and ecu or you will impart an offset.

350km out of a tank of gas is terrible... B20 or not. Assuming a typical 11 gallon tank, that's around 20mpg. Sounds like the car is generally running pretty poorly. You most likely have a few issues going on.

At this point, I would say you need to seek the help of a professional. Find a tuner who is qualified with your tuning platform or at least a mechanic who is familiar with modified Hondas. Have him go over car and give you a list of things to fix, and take care of the entire list before you go to tune. Honestly, any tuner worth his weight will refuse to work on you car until it's mechanically sound anyway.

Fix your grounding issue (if you're just body grounded), adjust your fuel pressure until the AFR's are somewhere in the neighborhood of 13.5-14.5 at idle and cruise, and drive it gently to the shop. When I say gently, I mean that if you are pulling away from a school bus at traffic lights then you need to back off.

Edit: I see that the motor is freshly built and not broken in. Stop where you are and tow it. If you've already been driving it around, you may have already screwed the pooch on a proper break in.

 

Hey thank you so much for the info. . I have not put the c5 in yet and this b20 has been running like this since I bought it 11 months ago. I will run the ground to the ecu or thermostat housing ground in a couple days when I get the time too I've been really busy with work and Christmas. I was suppose to have the c5 in by now but I think it might be next month now. Ill be driving this one till then and then it will be my first motor I'm going to take apart and clean up n put back together. All motor b20vtec and later in summer hope to turbo the c5 motor. I'm going to have to wait and see how the c5 runs when put in. Cuz the random reving 1-1600 might be a vac leak or maybe a sensor or maybe the ecu trying to compensate I dunno. Thank you very much for the good info. I still don't understand open and closed loop. And I don't know what software my ecu is running. I have no way to check. Thanks alot.

 

You're welcome. I would highly suggest that, when you get the new motor in, that you fire it up just to get it up to temperature and check for leaks and set the fuel pressure and such. After that, shut it down, change the oil, and tow it straight to your tuner to let him handle the break in on his dyno. He should be able to provide you with a basemap to get it going. It's a small price to pay to protect your investment.