GSR Swap w/ S2 Intake Manifold
 

So, last summer I swapped an OBD2 B18C1 into my OBD2 LS Integra. When I did the swap, I also upgraded the intake manifold and throttle body to a Skunk2 ITR replica manifold. I noticed after doing the swap, that the car would smoke when I would accelerate hard, and also when I let off the gas. I had no oil mixing with coolant or anything like that, no overheating issues, just a white-ish smoke and a burnt smell of some sort. But when I did a compression test, cylinders 2 and 3 were about 30 psi lower than 1 and 4.

Eventually, I took the head off, had a machine shop check the flatness and it was within .001" so I know it's not warped. While I was at it, I replaced the head gasket with a Cometic, installed ARP head stud, extended ARP intake manifold studs, Golden Eagle thermal intake manifold gasket, Supertech titanium valve springs and retainers, Gates timing belt, tensioner and water pump, and OEM valve seals. Before I assembled everything, I cleaned up the valves with a steel brush wheel and then lapped the valves. I made sure to do a valve adjustment when I put everything back together.

Now, I got it back up and running, timed it and made sure fluid levels were all where they should be. Unfortunately I'm still smoking the same as before. My suspicion is that the vacuum lines and coolant lines running to and from the intake manifold are messed up. Because I noticed when the idle drops down at a stop, right after decelerating, the smoke corresponds with the drop in idle.

I know I still need to try another compression test, and if I get any low readings, I will do a leak-down test. Any recommendations as to whether I should do this cold or when the engine is up to temperature?

Also, does anyone have any specifics as far as going from a stock GSR intake manifold to a Skunk2 ITR replica manifold? I need to figure out if maybe the vacuum lines and coolant lines are routed incorrectly.

The Integra is my autox car, and I only drive it from May to about early October. It does not get driven in the winter.

Re: GSR Swap w/ S2 Intake Manifold
 

I did a compression test today, the car has been sitting for 2-3 days so it was a cold test. I got each cylinder around 135-140psi but I didn't realize I was supposed to hold the throttle body wide open. When I added a half a cap of oil into the cylinders and rechecked them, compression only jumped up another 10psi at most. Should I re-validate?

Re: GSR Swap w/ S2 Intake Manifold
 

Re: GSR Swap w/ S2 Intake Manifold
 

How are you running the coolant lines and the evap?

With the EVAP, you need to run a Tee fitting from the front port of the Skunk2 which splits it from the PCV valve/blackbox and the EVAP solenoid or purge valve (cant recall which, but its the one that used to be part of the original intake manifold). The cooling lines I ended up looping them instead of blocking them off.

Re: GSR Swap w/ S2 Intake Manifold
 

I'm currently redoing the EVAP system on my chassis because I have a 1997 Integra LS and I'm running a 1998 Integra GSR ECU, so it's looking for the extra sensors on the canister and gas tank. Once I figure out the wiring, I'll see if that helped change anything. I'll have to check the map sensor, but I'm pretty sure I swapped it over with the o-ring and everything.

Re: GSR Swap w/ S2 Intake Manifold
 

I ran running the LS evap components that I took off my old motor to put on the swap after I swapped in a GSR. I haven't had any issues, but I am running a P28 OBD1 ECU with Hondata with the EVAP system inverted because I couldn't deal with the smell

Re: GSR Swap w/ S2 Intake Manifold
 

Sounds potentially like piston rings. Leak down test could confirm.

Compression test is best done dry and cold, with throttle wide open (as it's supposed to be) for best readings and to give the most detailed look at possible loss. What are your numbers under these conditions?

Re: GSR Swap w/ S2 Intake Manifold
 

I did a compression test when the engine was up to temp, with throttle wide open and my numbers were 235-240-240-235. Looking at my spark plugs, all of them looked okay besides the one (see pictures) which looked black and covered in soot.
https://cimg0.ibsrv.net/gimg/honda-t...aa345fc562.jpg
https://cimg9.ibsrv.net/gimg/honda-t...d871221dea.jpg

Re: GSR Swap w/ S2 Intake Manifold
 

My issue is because between 1997 and 1998, Honda changed the EVAP system so my ECU for the GSR swap is looking for a sensor on the gas tank and charcoal canister, which my 1997 chassis does not have. If you look at the part diagram for the EVAP system between the two years, you'll see what I mean.