Please help b16 very weak!!
 

Hello everyone my name is Korey. I am the owner of MOTOROLOGY recently a customer brought in a 97 civic that had a b16a swap done at another shop. The reason he brought his car to me is that it is slower now than it was with his fairly stock sohc non v-tec. Now to start this swap looks pretty poor to me the other shop left a tranny mount bolt out witch in turn tour the driver side motor mount out of the block they then fixed this with a fabed mount that comes of the bottom of the block and over to the frame rail, I also noticed that all of the wires were just twisted together and elec taped most of witch are coming apart. Now as I started to go through these problems I decided to check the cam timing I then noticed it was about 1 tooth off and the belt was very loose so I corrected this and also made the belt nice and tight. But it still is not running right when the motor is cold it pulls all the way to 8k but ounce it is warmed up it falls on its face at 6k almost like its hitting a rev limiter. I think this could be related to the 02 sensor but I am also going to check dizzy,wires,plugs and FPR. Any input would be very helpful Thanks

P.S. I did a compression test with it warmed up at WOT and got
#1. 175psi
#2. 165psi
#3. 175psi
#4. 175psi

Re: Please help b16 very weak!!
 

it's not throwing any codes? Did they stay with OBD2 or did they convert it to OBD1? 02 sensor is a possibility however in my experience when you floor it it will eliminate the problem because the ecu goes into open loop mode under full throttle acceleration. So if it's still falling on it's face at 6k there's something else going I would think. Did you check the basic maintenance items? Other than that i'd start start checking the ECT sensors. Sounds like one of them could be skewed and that could cause a temperature reated problem like that.

Re: Please help b16 very weak!!
 

is vtec engaging or does it seem not to make much power over 4500-5000 rpms?

What is vtec being controlled by? ECU, rpm switch, vafc?

Those compression numbers seem low to me I think the manual says lowest is 185 and highest is 235 w/ 28 psi allowable difference between cylinders...

My OBD0 B16a was 220, 210, 210, 220...

Re: Please help b16 very weak!!
 

Well v-tec is being controlled by the ecu and I am pretty sure it is working I can here the change in the intake note. And yes I thought that the compression was pretty low to so I would like to find some more out about that. Meanwhile I will start running through the ECT, dizzy, wires, plugs and also the really sad wiring job. Thanks

Re: Please help b16 very weak!!
 

Also there is some type of a conversion harness on the ecu so i think they converted to 0bd1. Thanks

Re: Please help b16 very weak!!
 

lol, you just think? You can check for sure you know, just look at the ecu code.

Re: Please help b16 very weak!!
 

SO let me get this straight, you own a shop yet you don't know the first thing about vtec hondas, or trouble shooting, and you can't determine if a car has been converted to OBD1? Are you okay?

Re: Please help b16 very weak!!
 

LOL...sounds just like the majority of "tuner" shops in PA.

Re: Please help b16 very weak!!
 

Sorry my wording was in correct. Yes I know for a fact that it is 0bd1. And don’t flame on me for owning a shop I make good money and have a lot of satisfied customers. Please excuse my ignorance I am fairly new to b16's but have built a lot of d-series and I also do a lot of Rotary performance like my turbo Mazda fc3s Rx7. I really hope to make some friends here at HMT you guys all seem to be cool guys unlike the guys at Honda-tech. I mean when H-T says something cant be done you guys find a way to do it and also most of the time people don’t get flamed on when they come to HMT with problems. To tell you the truth I like HMT so much more than Honda-tech that I will donate 10% of my profit on fixing this civic to HMT if you guys can help me figure out what is wrong with this b16. Thanks

Re: Please help b16 very weak!!
 

right we are better than HT, but you gotta expect to get roasted a little. I mean you don't have shop manuals or any online resources to help you? Plus if you've worked on D series motors, a B series very similar. Granted it sucks that car is obd1 because i doubt you'll be able to get a scan tool on it now, but if you can, get us some of the PID data. that may help with some things.

Re: Please help b16 very weak!!
 

When someone brings someone elses junk to me...I tell them straight up that its going to be a pain in the ass for me and I'd rather take my time and do it right my way. From the sound of it....I'd first fix the mount (as you did), then fix the timing. Then see if theres any chips insid the ecu to change fuel, timing maps. I'd also check for ghetto rigged crap on the harness. I'd start by redoing the harness to cleanup wiring and cleaning of plugs. Pulling the engine harness out and redoing it should be a breeze if you know your sensors(from years of working with hondas) and what goes where. I'd start with that if I didn't have a direction to go. A car can have semi bad compression but still run pretty good. Turn the car stock specs first. Look into the normal maintenance...like plugs, wires, cap, rotor, grounds, fuel, filters, timing, valve lash, cam profile, etc. Do the easy and work your way up. Good luck to you.

Re: Please help b16 very weak!!
 

Honestly your first statement doesn't make sense. When a b16 is cold, it should only pull to around 6500 with no vtec, and warmed up with proper oil pressure will rev to 8k w/vtec. A code for either the vss, knock sensor, or o2 sensor will keep the motor from seeing vtec, so it's possible that that's a problem too. Also double check that timing belt. I know from personal experience (many times over) that dohc timing belts are an absolute ----- to get lined up the first time. Make sure the crank is set at the tdc mark and not the 16* btdc and that the dots on the sides of the cam gears are line up perfectly as well. Most of the time you have to line up the crank and the exhaust gear and leave the intake off 1 tooth so when you tighten the belt it pulls it into position (or vice-versa with the gears, which ever way you can get it to work...but one will have to be off in order to line it up when you tighten the belt). If either one of the cams or crank is still off one tooth it'll account for the low compression numbers.

Re: Please help b16 very weak!!
 

good luck with the wireing, i know i hate trying to go in and fix wire problems after it has already been screwed with. a friend of mine had a guy wireing his d16z6 into his obd0 hatch and i swear the guy used speaker wire and red wire for everything. that was a pain in the ass to even look at. we would follow a wire and lose it in the cluster ---- of other wires, or be traceing a wire and be like "WTF? ???, why would you do that.....?".

Re: Please help b16 very weak!!
 

the compression numbers are not really low for a b16 thats been beat on, my b16 had 170's across before boost, then after 6 months of 8-9 psi it had 150's and 160's and still ran PERFECT! the comp. numbers are sending you in the wrong direction, pay no attention to that, you most definitly have an ignition system problem....

Re: Please help b16 very weak!!
 

compression also relys greatly on if the car is warmed up and if the throttle is open.