91 Civic HB smoking.

[stanlam]

I have a 91 Civic HB that was smoking(D15B1). Did a compression check and numbers were very low. Pulled apart and done a ring job. Head was cleaned up at the local machine shop(replaced a valve ) New head gasket also. Reinstalled and was smoking even more.Looks like white smoke.Changed out lower end with a D15b7 using the D15b1 head and the DPFI intake. New head gasket and intake manifold gasket. Running smooth and good compression numbers but still smoking. I let it run for 20 minutes and brought RPMs up.( smoking like a freight train) Finally got a fault code #1 for O2 sensor and engine started surging. I dont know the capatibility between a B1 and a B7. Can I put the B7 top back on the bottom and run DPFI left over from the b1 that was in there with the b1 ECU ? I would like to get my little car back up & running. Any help or insight would be greatly appreciated.

[Tony]

Should be able to swap the intake manifold over to keep the DPFI.

[RottenCRX]

Try preforming an exhaust back pressure test. Your cat could be clogged and gue'd all to f^ck.

[stanlam]

can u explain the backpressure test? I can start it up now and it doesnt smoke. When i take it out on the road up to speed(60 mph) it will start smoking. I pull back in the drive and no smoke.

[RottenCRX]

Originally Posted by stanlam

can u explain the backpressure test? I can start it up now and it doesnt smoke. When i take it out on the road up to speed(60 mph) it will start smoking. I pull back in the drive and no smoke.

You would start by removing the o2 sensor before the cat and installing an exhaust back pressure testing gauge like one of this guys.


Start your engine for 30 seconds and record the results. Pressure should not exceed 1-2 psi.

[RottenCRX]

Originally Posted by stanlam

can u explain the backpressure test? I can start it up now and it doesnt smoke. When i take it out on the road up to speed(60 mph) it will start smoking. I pull back in the drive and no smoke.

How many kilometers are on the car. Chances are you need a new set of piston rings.

[rustyfishook]

I'm having the same problem with my 91 crx si. Bought the car with a possible blown head gasket(original owner took the liberty to remove the gasket with the head still on the car?). I Replaced the entire gasket set, had the head worked over with new seals and a valve job. I got the car started and blue smoke plumes out of the exhaust. I thought maybe the cat was gooed up and disconnected the exhaust, no change. Any ideas?

[RottenCRX]

Originally Posted by rustyfishook

I'm having the same problem with my 91 crx si. Bought the car with a possible blown head gasket(original owner took the liberty to remove the gasket with the head still on the car?). I Replaced the entire gasket set, had the head worked over with new seals and a valve job. I got the car started and blue smoke plumes out of the exhaust. I thought maybe the cat was gooed up and disconnected the exhaust, no change. Any ideas?

Blue or white smoke is common to come from the exhaust on the first or second start up but should return to normal. If you still have thick blue smoke you would then invest in another set of piston rings/ remove any ring ridge, possibly have your cylinder walls honed, inspect various areas of tolerances, measuring oil clearances and well... your going to have to have your block rebuilt buy this point.

[rustyfishook]

I've run a compression test and it's 180psi across the board. I haven't run a leakage test though. And it smells as if it's running rich.

[RottenCRX]

Originally Posted by rustyfishook

I've run a compression test and it's 180psi across the board. I haven't run a leakage test though. And it smells as if it's running rich.

Well i'd have to be there to give you a proper diagnosis, i'd take it your a licensed service tech if your worried about it.

[H4Bangin]

white smoke = water
blue smoke = oil
black smoke = air/fuel mixture

[danielsatur]

Are you sure they put new valve stem seals in!

[H4Bangin]

valve stems are for rims

[stanlam]

Well i ended up buying another civic. (1990 4 door w/trashed tranny). Transplanted engines and got some smoke like before, Gave it a shot of engine restore and everything cleared up. I still have the previous engines that will be gone through with the weather breaks. At least i'm up and running.

[rustyfishook]

Originally Posted by H4Bangin

valve stems are for rims

Yeah, the machine shop told me the schraeder valves were blown, duh