I just put in a d16y7 to replace my 91 HF engine. I keep getting a code one on both pm6 and pg7 ecu. No code with original pm8 ecu(actually getting EGR code, but I know that's because the new engine doesn't have one). I'm pretty sure my o2 sensor is good. I get the same results with a couple different sensors.

What are some things to cause the sensor to register a code. Car idles real low with pm6 or pg7 ecu. Idles okay with pm8, but no power like the other two.

Using d16y7 block and head from 97 civix ex. b7 intake manifold. It's now in my 91 honda crx HF.

Car has a hard time getting up to speed when idling so low (around 500rpms) but after driving for a while it idles around 1800 and sometimes around 2900 when driving a bit harder.

Another thing I've noticed is once the check engine light comes on for o2 sensor the car get a huge increase in acceleration. I'll just be driving the car gets up to about 3300 rpms the light comes on and bang, it's like a little boost or something.

Anyone have any suggestions on what would be causing these little problems?

Thanks,
tk

 

up

 

are you using the HF o2 sensor or the y7?

 

I've got abut 5 different o2 sensors. From various civics not all HFs, but they all look identical. I didn't know there was a difference. None of them are from a Y7, but I'm also not using the Y7 computer. I've got my original HF computer. That doesn't register an O2 code. The other two, a pm6 from a crx Si, and a pg7 from an older integra, both throw a code of one flash. I believe that is an oxygen sensor code. Would a y7 oxygen sensor plug into my wiring harness? And does it sound like from the other symptoms that would be the problem? I'd hate to put out $100 or so for a new o2 sensor and that not fix anything.

thanks for the reply.
tk

 

that one flash isnt the flash when you first turn the key to ON is it?

 

no, it's a consistant flash. I get a check engine light.

 

bump. change me o2 last night .. no change in idle.

 

I talked to a friend of mine last night who I bought the engine from. He was going to have an ls put in, but never panned out, so he got another d16y7 from a ?2000? civic.

He suggested advancing the timing. He had to advance his so far he had to build a new bracket for the dizzy. I'm not going to go that far, but I'm gonna go try and advance it in a bit to see if that helps any.

Any other suggestions?

 

if he had to advance it that much i bet his timing belt is off a tooth.

 

I don't know, I'll mention it too him. I just advanced mine as far forward as the distributor would go, and it seems to be running real smooth now. Good power throughout the rpm range. It was previously lined up right with the center red marking. I didn't check the timing, I just turned the distributor all the way. What is the ideal timing supposed to be set at? With only three marks on the pully how is it supposed to be set precisely?

I'm still getting code one, but all other problems have seemed to be ironed out.

I'm gonna double check make sure I still do not get a code with the hf computer.

Another thing I wanted to check is the wire from the harness to the o2 sensor. How would I go about checking that for breakage? I guess I have to check for continuity at the plug from the sensor, and the plug at the ecu plug. Does anyone have a diagram of the ecu pins? Is there an a better way to check it?

Thanks for all the help.
tk

 

thats a good way to check for a breakage.

I believe the o2 is on c16 @ the ecu.

 

c16? How would I find that. Is it labeled? I'm sure there is a diagram available somewhere, but I don't know what to search for. This is what I found, but I can't really read anything on it. Anyone have a better diagram?



Also trying to find what my timing is supposed to be set at.

Thanks again
tk

 

I've also found this rather helpful for anyone following this thread

http://www.fourthgenhatch.com/mpfi.html

Continuity check shows wire is fine. I guess this is my next step