1990 Integra Driveability Issues - Help Wanted!

Hi All,

So, this was going to be my challenge car.  Work has decreed that a personal life is overrated, so no challenge for me this year.

Background:

Bought it with a blown engine, but otherwise good shape.  Swapped in a junkyard B20 and the car is running and driving *fairly* well.  However, it has a few lingering issues, and because I never drove it pre-swap, I don't know if it's something I did, or a lingering previous owner issue.  I un-berkleyed a number of his mistakes during the engine swap.  Symptoms:

-Poor fuel economy (est ~18-22mpg in not aggressive driving)

-Stumbles on throttle tip in and setting off from idle, smooths out at high rpm/load (actually pulls pretty well)

-Lots of vibration at idle, almost like a misfire/running on 3cyl (checked, and all cylinders have spark).  I will try to get some pics/video soon.

Parts replaced: distributer (old one puked out), 02 sensor, fuel filter.  Also did the timing belt/tensioner/WP while swapping the engine, and replaced most of the motor mounts. 

Engine is from (I believe) a CRV.  Used just the long block, exhaust and intake manifold came off '90 integra engine, as did fuel system and distributor.  So it's a B20, but still running the B18's OBD0 controls. 

Any thoughts from those of you with 90s Honda/B-series experience? 

Alternatively, since I'm not making the challenge, and have enough cars, I am really just fixing/cleaning this in preparation for eventual sale.  If someone wanted to buy it as-is and save me 3-4 days of washing, polishing, and tuning, I could probably make a deal for Challenge money. 

I bet you have an injector problem, maybe stuck open or close to it, which is why it is using lots of fuel, also making tip in rough as it is too rich, but also why it is fine at full power.   Either send them out to get cleaned/tested or get a new set.   

I would also do a compression test. Simple non intrusive and will ruel out a lot. 

Valve adjustment?  Hondas like to get tight and when the valves hang open all sorts of weird issues arise.

Would want to double check cam timing, too.  

That sounds like a blown headgasket. Check compression and pressure test the cooling system.

I second compression & leak down testing. I know the k24 crv engines were bad about burning exhaust valves.

In reply to Caperix :

Only when the valve adjustment was not done in time, or adjusted improperly, from what I have experienced.  D series too.

With those light springs it is really easy to get them adjusted wrong.  You can shove a too thick feeler gauge in there remarkably easily, and in a lot of chassis, access to the valves sucks, need to have a set of gauges that are bent either by design or by hand.  It is not hard to get them waaaay too tight.  Then they have an idle or low speed misfire that goes away with RPM and or load, and is temperature dependent when they are right at the edge.

I think this is why Honda went from "adjust the valves every X service" to "audibly check valve clearance every X service".  If you cannot hear them, they need adjustment 

Pete. (l33t FS) said:

Valve adjustment?  Hondas like to get tight and when the valves hang open all sorts of weird issues arise.

 

Would want to double check cam timing, too.  

Doh...that is definitely a Honda thing, and I never even thought to check clearances on the longblock.  Will break out the feeler gauges tomorrow.

Hopefully it's not a headgasket/burned valve.  I don't have time to pull the head :(. 

Bumping to say thanks Pete, I owe you a beer (and this forum rocks)!  Not 100% sure yet that's the issue, but the clearances were tight on #3 and #4 exhaust side, and all over the map for everything else.  Timing belt marks looked good.

Plugs look good (or at least even):

Reason I don't know if it's fixed yet is I took the car apart for a deep clean and detail, hopefully have it back together this weekend for a test drive:

Looks great! Be careful- this is now a relationship starts that is is hard to end- ya know, with a car. 

I don't want an old Integra, I don't want an old Integra, I don't want an old Integra, also mousetrack seatbelts infuriate me...