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Is there anyway to correct the Fuel/Air mixture with this current set up…
This question is related to this post from another thread:
[color=green]I think this is the correct category for this question? I bought my ’91 civic three years ago as a cheap AtoB. The automatic tranny was rough back then, and the thing still goes! It’s true what they say about this generation of Honda. The thing is, if I really want it to continue to go, I think I need to solve the tranny issue which I believe is truly an engine SWAP issue.
The original engine was swapped out for a D16Y7 engine. This engine is not popular, but I think it’s pretty cool for a fuel econo build because it’s a 1.6L aluminum engine which means light weight.
However, the tranny is stock, the ECU is stock OBD0, and there have been no adjustments made to the fuel injection, which is stock.
From my research I understand that transmissions before 1996 where not hydraulic, and apparently some sort of adapter is required for older model trans to 1996 and up engines?
I have also been told that the hydraulics are how the transmission works – and nothing to do with the connection to the engine or how the engine drives the transmission… I have no idea.The OBD0 has no way to read the sensors from an OBD2 engine. So I am not sure what the oxygen sensor is connected to…
And since the OBD0 cannot read the sensors from the newer engine, I do not think the correct fuel/air ratio is happening at the injectors especially because the stock engine was 1.5L…
I want to keep this engine. Do I fix this transmission, and get a new ECU? (I am thinking aftermarket instead of making everything work for an OBD1). I WANT to convert to manual, many people say its not worth the effort. If I have to get a new tranny anyway, what, all I would have to do is get the pedal assembly, angle grind a clutch pedal whole in the firewall install the assembly, and install the clutch cable and new center console, right? I mean, yeah it’s work, but is it really THAT complicated?
WWYD?[/color]
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I have swapped obd0, obd1, obd2 and k series in plenty of civics but never the direction you’ve gone. So what I say her is theory and shouldn’t necessarily be taken as gospel.
In theory, an obd0 D16A1 computer should be able to run the D16Y7 if all the obd0 sensors/manifolds still bolt up (never researched because benefit < investment). I'm thinking you need to get your hands on an obd0 D16A1 USDM ECM, D16A1 intake manifold and injector resistor box as the D15's were TBI. Again all theory here, but I would suspect that Honda's engineers would have upgraded the Y code heads for better flow and chances are (and total assumption here) you're still running D15 TBI and the injectors are maxed and can't compensate for the better flow and displacement. If all goes well, you should be able to retain your A/T and just upgrade to 1.6 PG-MFI.
Right. My point is that you have dual-point (2 injectors spraying into the throttle). But the engine you’ve chosen originally would have come with 4 injectors (MPFI), each one spraying directly into an intake port. Even though I’ve never looked it up, I’d be willing to bet the dual-point system is just not good enough to feed the 1.6. In fact, this was the capital difference between the DX and the SI outside of 0.1 liters of displacement. In a sense, and I am oversimplifying here, you upgraded to an SI motor but didn’t upgrade the management to SI specs and the two are quite different. You need to go find an SI and rob the intake manifold (throttle body/fuel rail too), injector resistor, wiring harness and ECU. That should be everything you need to get started. I would also recommend getting the SI ECM’s connectors with about 6 inches of wire because you’ve only got 2 injector wires and you need to pin in 2 more. (I think there is other wiring too, if you go through with the swap, hit me up and I’ll look it up). On top of that the fuel lines and the throttle linkage will be different too. Though, if memory serves me correctly you can use the 1.5 throttle cable but you have to rig it to work. Sorry, I haven’t touched a 90’s civic in over 12 years.
Both the Dual-Point (1.5) and the MPFI (1.6) have a PGM-FI sticker. The 1.5 had a black box with the sticker on it. The 1.6 had the sticker affixed to the primary runner of the cast aluminum intake manifold.
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