Background: 89 dx hatch, 270,000mi, all stock, smokes like crazy and uses about a quart every 300 miles, no noticable loss in power, compression was 130,150,130,130. I replaced the valve stem seals in an effort to reduce oil comsumption. No improvement. Also adjusted all valves to specs - they weren't off much at all anyways.

I was driving from Philly back to Richmond and with about an hour left, I felt something a little unusal(highway I95). I couldn't quite place it. It just ran a tiny bit rough. I pulled off the highway to see what the issue was. The slower I got, the worse the car ran. Finally, at a stop, I realized I had to have a cylinder out. I pulled spark plug wires one at a time and narrowed it down to the driver's side cylinder of the two in the center. I was getting spark, so there was nothing I could do on the road except try to make it to Richmond.

It did. No problems at all, other than rough idling. After messing with it a little more, I find that the problem cylinder has lost compression. It is now about.... 5psi? I know the piston is going up and down, the valves seem to be going in and out ok(they do go in an out, whether they seal or not is a good question).

How would you guys proceed? I do have a zc that I just need to put back together. I initially bought the car to do the swap(was smoking when I got it). I had bought the zc and did a total teardown(my first attempt at something this involved) of it and replaced/resurfaced everything - it'll be a new engine after I put it back together.

Do you guys think the dx motor can be repaired simply and cost effectively so I can squeeze out whatever life it has left? Do you guys think I could get back to Philly on 3 cylinders to do the swap? The zc is in philly. I'm open to all suggestions.

Sorry for the book, I look forward to your comments.

 

first thing is a leakdown test to determine where the loss in coming from. more than likely the rings from the looks of it. Just slap in the zc and keep it dpfi if you dont want to go through converting it over to mpfi. try to drive it home, screw it, see if it makes it

 

the zc can run dpfi? i thought it only ran mpfi. I have an si wiring harness, si trans, pm7 ecu, the little relay box or whatever it's called, si throttle body, ebay intake, dcsports exhaust manifold and downpipe, dc sports cat-back, and a new high flow cat waiting to be put in with the zc, that should be the complete swap to dpfi and maybe make a few extra horsies. oh no, I still need to get a new clutch and flywheel. I think I might use the stock flywheel, just replace the clutch... I don't know. I'm open to suggestions there too. What flywheel and clutch should I use?? Remember, "cost effective". hahaha, this build as a whole turned out not to be very cost effective, which is the reasoning I gave my girlfriend for buying it in the first place. "It's good on gas and will last forever and has good resale value and it's a good investment in general." haha I've put more money into this car than any other used car i've ever had! And I've had quite a few. AND it still doesn't run right yet. I'm thinking good thoughts though. It'll be a lot of fun when it's done!

 

you can put the dpfi intake manifold on there and keep it dpfi. if you have all the parts for a mpfi conversion, go for it

 

ooohhhh, I didn't know I could do that. That would be a little quicker and I wouldn't have to worry about all the wiring for now. I would still need to reverse the distributor wires, right? Will the dpfi intake manifold match up with the zc head? I know the exhaust will not without some porting (that's why the dc sports stuff). How will the motor run as a dpfi as opposed to a mpfi? Will it be bad to break the engine in as dpfi instead of mpfi? I wouldn't think so, but maybe somebody knows something I don't.

 

from what I remember, you can use all of the d15 stuff on the zc motor and keep it dpfi. someone correct me if I'm wrong

 

the only thing I know won't line up exactly is the exhaust manifold. The mounting holes and the intake ports are skewed a tiny bit. You just need to take a grinder to it to make it match up. But I bought a manifold that will fit.

 

You're talking about a DOHC ZC. Is your motor DOHC? The SOHC ZC will line up fine.

 

yep, dohc of course.

 

In that case you can't keep the DPFI

If it was SOHC though, this would be true:

 

...oh

 

hahaha I should have asked if it was a dohc

 

haha yea, little more work and parts involved then