Honda D Series Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I'm a little stumped by my d16a6 right now. Its a long story, but I could use some help.

A couple of months ago I started doing a mini-me swap on my 91 CRX using a y8 head, a z6 intake manifold, TD41U dizzy, P28 ecu, etc. Well I got busy, and now I'm leaving the country for a while for work so having not finished the swap, i decided to return the motor back to stock, using only the z6 intake.

I decided to clean up the a6 head a bit before putting it back in. So I scraped off the old gasket material. I pulled the valves, which were coated with carbon deposits front and back, intake and exhaust. I soaked them in a parts cleaner then wire wheeled off the deposits. I then lapped the valves a little bit. I reassebled the head and installed it back on the block, replacing the oil control jet and using a later model 3-layer metal head gasket. I aligned the cam, and timed the ignition to stock specs. I did however re-use head bolts... for the second time.

A couple of days later I noticed some smoke behind me as I accelerated away from a stoplight after work. I pulled over, opened the door and hit the throttle. I noticed my car producing a fair amount of light greyish looking smoke at all engine speeds. Upon closer inspection I noticed it was also spitting out a lot of watery carbon residue onto my driveway. I checked the oil and the coolant and both were low, but there appeared to be no mixing.

I wondered what it could possibly be. The d16a6 motor has only seen about 130k miles total and prior to starting the mini-me swap had never burned an ounch of the mobil 1 its been fed forever. So I checked the compression using a gauge and in a few rotations found about 152 - 155 psi in each cylinder.

This had me stumped. Because of the watery carbony mix and the smoke coming out of the tailpipe I figured the metal head gasket wasn't sealing well on a cylinder head surface made imperfect when scraping off the old gasket. So today I quickly pulled the head and installed a stock type steel core laminate head gasket and ARP studs.

Started her up and shes still spitting out of the tailpipe as bad as ever. This was after about 2 minutes of running in the driveway:



I am starting to get frustrated. I checked the PCV valve and the valve cover vent and both seem to be fine. I unscrewed the oil cap for a second and as I pulled it back saw some oil drops spewing out, but I think thats mainly a function of the valvetrain.

I'm stumped. The compression test seems to rule out the rings. If the head gasket were not sealed well enough, wouldn't it have showed in the compression test?

The valve seals and guides never had had any problems a couple months ago when I stopped driving the car.

Another thing I've noticed is that the gas mileage has gone down from mid 30s to low 20s.

I've got a fair amount of experience with different engines. but this has me stumped. Any engine builders out there have any ideas? its killing me to have a sick crx.

Help!
 

·
D-series Janitor
Front Engine Dragste
Joined
·
1,220 Posts
looks like its dumping gas to me. Especially with the gas mileage thing.

When I dyno'd my car it dropped down to 11.5:1 after 4500. It spit up black sludge all over the ground and straps that were holding it down in the back.

I would say check the A/F.
 

·
Registered
Joined
·
33 Posts
My car had a lot of water coming from the exhaust after a rebuild and the first few starts. More than what you're showing on initial startups. Then at the dyno I had a puddle which was probably a gallon or so of liquid. It eventually went away, and my tuner said it was nothing to worry about.
 

·
Registered
1995 Civic EX Coupe
Joined
·
579 Posts
could just be burnoff from the parts cleaner. Its happened to me many times also and i freaked out, but after a little driving it went away.
 

·
Registered
Joined
·
42 Posts
I'm gona have to say your not burning fuel efficiantly too. Have you checked if your getting good spark from your ignition system. You also may have an injector leaking.

When you put the car back together did you keep it OBD 1 or did you go back to OBD 0?

Was the Z6 manifold bare or did it have the fuel rail and injectors on it?
If so are you using them?
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #7 ·
I'm back to obd0. I'm using obd0 injectors with the z6 fuel rail and pressure regulator. Perhaps the z6 fpr has a higher setting than the stock a6 fpr?

I'm also burning oil though.
 

·
Registered
Joined
·
42 Posts
I'm back to obd0. I'm using obd0 injectors with the z6 fuel rail and pressure regulator. Perhaps the z6 fpr has a higher setting than the stock a6 fpr?

I'm also burning oil though.

High fuel pressure can cause an engine to run rich, but I'm not sure if the Z6 regulator could cause it to run that rich.

As far as the burnning oil thats kinda odd. If compression is good and you didn't burn oil before then you would think it would be fine. The only thing I could think would be the most likely cause is your valve seals. You said you removed the valves to clean them. You may have torn a seal or two when you re-assembled the head. If the leak is bad enough you may be fouling out your plugs causing the rich mixture.
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top