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Discussion Starter · #1 ·
Well I just completed the WORST honda swap I've ever done...
Stef's HF has been waiting for it's D16A6 since april, the motor has been ready to go and sitting alone on an engine stand for months... and he finally killed the d15 at autocross.
So the last parts came in the other day, and we got the bottom end finished. Of course, the thing has been sitting so long, we're missing a bunch of stuff: oil jet, crank pulley, some hoses, flywheel bolts, pressure plate bolts, the TPS somehow broke...
So we're pulling the d15 anyway right... we'll get everything out of that. That HF held on to it's little motor to the very last. Every wire clip was still in there, every 10mm clip thing was stuck, I have cuts and bruises and burns all over. The passenger side axle nut would not come off at all, even after I cut through one side of it! The exhaust, instead of unscrewing, exploded into a storm of rust and broken bolts on the floor. One of the tie rods' end ball joints just broke at the castle nut. The battery drained itself while we were doing the swap. The HF exhaust manifold absolutely refused to cooperate. The bitch pin was easy to get out!

Anyway... we get the beast out, get the A6 (which looks like a damn fire hydrant, there will be pics to follow) together, tranny bolted up etc etc. We ended up pulling the axle out still attached to the HF knuckle, and swapped in some Si knuckles with fresh brakes.
The motor went in ok, as usual. We had to use the HF crank pulley for now because the alternator belt (which was new on the HF motor) was too long for the Si one. The HF pulley is a lot lighter for the record, but I think I've been told it's bad to use because there's no damper on it. Oh well, the PC680 won't last too long with no alternator.
The HF flywheel is also a lot lighter it seems. I didn't think to compare the friction area, but if it would work with a normal Si clutch it would be a nice alternative to an aftermarket lightweight one.
We also had to swap the TPS over from the HF's massive intake manifold to the Si one, since the Si's seems to have broken during it's stay in the shop. No problem swapping them, just used a cutoff wheel and made a notch for a flathead screwdriver. This may have caused a problem (below), but they looked identical, and from what I know all MPFI TPS are the same.

So after a while we got it in, and like I said, the battery was dead. We were also running open header, since the HF exhaust is only 5mm in diameter, and also because there's not any pipe at all left between the header and the muffler. Jumped the battery, threw an exahust vent hose on the header and crossed our fingers. We also had a fuel leak because I forgot to tighten the fuel filter lines, and one of the injectors (#2) seems to be seeping just a tiny bit. We have the seals for them, will fix them soon. Needless to say I was following the advice in the How-To forum, and had my hand on the fire extinguisher

After some coaxing in the battery department, it fires right up (no pun intended)! First thing I notice is, this motor is loud with open headers... but it's getting louder?! Also there were sparks shooting out from the flywheel cover (engine side, bottom of bellhousing). It was a little bent, but I defintiely didn't see it getting near the flywheel... weird. First thing Stefano noticed was the RPMs shooting up.
We let it run freely the second time, after I secured the flywheel thing. We didn't see any more sparks, so I assume it's ok, but the plate didn't feel hot or anything, so I'm not 100% sure I fixed it. The car ran up to about 2500RPM, and after a couple of seconds threw a Code 7 (throttle angle). I assumed it was the TPS... but it was plugged in. It worked fine on the HF too. Anyway so I took it off to make sure, and put it back on, same thing. We're kind of stumped. The only connectors not being used are EGR on the harness side, the PCS charcoal thing on the harness, and the thingy on the back driver's side of the Si manifold. It's a 2 pin connector coming out of a cylinder, I remember seeing the other end of it on my Si harness before I modified it, I don't use it with OBD1.

So the good news, we are getting it closer to an Si, but the bad news is it wants to be a Y-49 Si. We still have to bleed the brakes tomorrow, replace that tie rod and the axle nut before we can drive the thing. Also we should get some exhaust on it, maybe get something welded up tomorrow evening.

Enough... I gotta sleep.
 

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Discussion Starter · #4 ·
That thing on the back of the Si manifold I'm talking about is the fast idle solenoid valve. There doesn't seem to be a plug for it on the HF harness... could that be the issue? Would that possibly make this happen? We are going to try the HF ECU to see if that works, since it doesn't need the valve.
 

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I imd you this stuff to, but here you go. that needs to be hooked up for sure.

Next is the fast idle control solenoid valve (F-I-C-S-V), which is mounted on the back of the Si intake plenum, near the EACV. it's plug uses 2 wires: black/yellow and a blue. Black/Yellow (later referred to as B/Y) is a 12V + and routes to the B/Y from the EACV plug. The Blue wire goes to pin B2 on the ECU. B2 is currently connected to the green/yellow wire from the "shift up light" in the guage cluster. The plug for this wire contains a green/orange and a yel/red wire. It is under the driver's side of the dash, connected alongside the fusebox with a white plug. Cut the green/yellow wire from the plug on the harness and splice in the blue wire from the Fast idle control solenoid valve, with the new wire going toward the ECU. Don't connect the F-I-C-S-V wire to the plug under the dash, or weird stuff will happen with your shift light! The "shift up" light is now disconnected (YAAAAAA!!!) and the green/yellow wire on the plug under the dash now hangs bare. F-I-C-S-V wiring is now complete.
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Discussion Starter · #6 ·
Thanks Matt, always coming through for me!

I don't know if that helped much though. It seemed that the throttle cable was stuck, if I held the spring to where it should rest it would idle ok now, after it's warm it idles around 1000RPM. A little high but acceptable. Still throwing the code for TPS though... and again the TPS is known good off the HF, the car ran fine before the swap. We also ran it on the PM6 once to see if the distributor would work when we weren't sure, and it was fine then too, no codes.
 

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i didnt plug in that black c3po looking thing on the back of the manifold when I did my A6 swap a while back. shouldnt make a difference. what issues are you having now?
 

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Discussion Starter · #8 ·
chemik said:
i didnt plug in that black c3po looking thing on the back of the manifold when I did my A6 swap a while back. shouldnt make a difference. what issues are you having now?
Getting a code for TPS, which I swapped from the HF to the Si manifold.
 
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