I just dropped a d16y7 into my 91 CRX HF(thanks to the help of honda-tech). Would it be bad to run it with the HF ECU?

I've got an pm6 ECU from a Si on the way, but it could take a couple weeks. Could I hurt my new engine by running with the old HF ECU?

I also have another pm6 ECU in my possesion, but it was from a 4wd civic with an automatic transmission. When I try that ECU in it, it throws an oxygen sensor code.

Which ECU would be better to run while I wait for my new one? I just wanna make sure I don't screw up this engine I just put in.

Thanks
tk

 

 

Now I'm trying a pg7 from 88 integra ls. Seems to be running much better, however it hesitates a bit when I first hit the gas. And when I'm not on the gas, the rpms wanna drop down below 500 and kill the engine. I'm also getting a code. One flash. Oxygen Sensor? I don't know what it is. I'm gonna check timing.

Any other suggestions?

 

Timing done, no difference still getting 1 flash with pg7 ecu.

any help?

thanks
tk

 

 

obd0, obd2??? what distributor, injectors, intake manifold, o2 sensor, etc are you using?

the hf ecu will be looking for the EGR, and will throw a code 12.

 

those ecu's you list will not support the y7 properly...as the y7, among other things, uses a 3-wire IACV, whereas the ecu's you mention support a typical 2 wire iacv...

 

been running with the hf ecu, it seems to run the smoothest. doesn't accelerate nearly as well as the pg7, but no hesitation or studdering problems.

pg7 throws one code. single flash

hf ecu throws code 12

more details

engine: d16y7 from 97 civic dx (obd2 i believe)
intake: b7? got it from a junkyard of a d15b7 engine

using hf distributor, injectors, and o2 sensor

 

Everything else not mentioned is probably from the HF.

 

I see, so you are probably running a 2-wire iavc from the hf if the HF ecu is not having issues with that-

Well, the HF ecu is on this planet for one thing- to save gas and support about 50 wheel horsepower with the utmost efficiently- I don't know if it will necessarily hurt the motor, but, it's something you want to use to just get the car from point A to point B, nothing more...

Why not put a y8 intake mani, b series TB, 240cc injectors from a y8/z6/d15b7/b16/b18 and use a chipped b7 ecu to run this thing!

 

or...

use everything you have already, except

get injectors from any 88-91 si or ex model civic/crx, 90-91 integra. (ive heard that 90-91 hf injectors are also 240cc...but im not positive)
use a pm6 or pg7 ecu...preferrably pm6.
get a different o2 sensor, new or used.

just to get it running good...keep the hf distributor, b7 manifold & tb.

after that go obd1 as builthatch posted above or stay obd0.

by the way what exhaust manifold are you using...hf, b7, y7? this may be why you throw a code 1, depending on the location of the o2 sensor. on the y7 and hf manifolds the o2 sensor is after the cat (i believe...without looking) and on most everyting else it is before the cat.

 

okay, that is something I forgot to mention...

I got a exhaust header with the engine...and I've ditched the cat for now and the rest of the exhaust is original.

Originally the oxygen sensor was right before the cat on the exhaust manifold.

Now it sits at the end of the 4-2-1 header. What o2 sensor should I use? Will it plug right into the harness?

The injectors I got from the intake manifold wouldn't plug into my harness, So I switched those back to mine.

The injectors seem capable. When I run the pg7 after it hesitates up to about 2800 rpms the then launches like a rocket. Seems to be delivering fuel okay, it's just that under 2500 rpms it won't do anything but crawl and I get a pg7 code 1. It's also not very smooth to drive, I'm either accelerating like a bat outa hell or I gotta coast, if I try to drive at a steady speed the car wants to jerk and lurch the pedel gets WAY sensitive.

With the hf ecu in, it runs about the same before I did the swap and getting code 12.

I would like to stay obd0 right now if possible. I don't know what it would take to switch to anything else, sounds like a lot of wiring.

I've got a pm6 ordered, waiting very impatiently for it. The pm6 I got from the yard is from a 4wd civic and does the same thing the pg7 does at lower rpms. Hopefully the pm6 helps, kinda wondering why the pg7 is running so rough though. Maybe I'm just not used to it.