ECU part number compilation

[Tippey764]

The f22a3 has flat top pistons. I bet the head might have a different cam then the a6 because of the higher compression and valve clearance but it very well could have the a6 cam. and it would HAVE TO HAVE stronger valve springs because it revs higher and has less piston clearance.

The valve springs in the a6 are pt5 part numbers

The cam in the a6 is a pt4

The valve springs for the a1 are pt7, yes pt7 thats the first 7 i've seen

The cam in the a1 is a pt3


So i don't think the a3 has different valve springs then the a6 since the a6 is already using pt5 parts.

[GhostAccord]

The f22a3 has flat top pistons. I bet the head might have a different cam then the a6 because of the higher compression and valve clearance but it very well could have the a6 cam. and it would HAVE TO HAVE stronger valve springs because it revs higher and has less piston clearance.

We are only talking 0.5 difference in compression. That's 4.1 cubic centimeters added to the top of an USDM F22A1-6. So from a -15.6cc dish top to a -11.5cc. IMO that's still a dish top.

What is the red line of the F22A3?

If it's Honda built. I'm sure they kept the same piston to valve clearances that they use in the majority of there economy engines. It wouldn't be any less because it's a 9.3:1 engine. Great for boost, not quite a high revving N/A street machine.

[Tippey764]

We are only talking 0.5 difference in compression. That's 4.1 cubic centimeters added to the top of an USDM F22A1-6. So from a -15.6cc dish top to a -11.5cc. IMO that's still a dish top.

What is the red line of the F22A3?

If it's Honda built. I'm sure they kept the same piston to valve clearances that they use in the majority of there economy engines.

The redline is 6500rpm

[drummersteve7]

lets not forget that the wagon speedo goes higher and has a different transmission gearing.

Could potentially lead to the ecu difference.

[Tippey764]

lets not forget that the wagon speedo goes higher and has a different transmission gearing.

Could potentially lead to the ecu difference.

I was thinking this actually since my friends wagon speedometer reads incorrectly.

[Nurega]

Does your ECU's part number match the one listed above?

Yeah, my ECU code matches correctly with the non-California 1991 EX Manual (37820-PT3-A23). I have a P12 manual ECU in my car; I'll post it's part number here when I get a chance this weekend.

[Nurega]

By the way, this thread should really be made a sticky after more of the blanks have been filled in.
Tippey, you should send evil_demon a PM

[Tippey764]

I pulled a 37820-pt6-a11

from my 1992 ex 5 speed sedan with 49 state emissions

They must have made the a12 revision mid year. my ecu was manufactured February 25th 1992 according to the date stamped on the side of it

[Hooligan90]

So, got a computer with a transmission I picked up to do a manual swap, and I notice there's two stickers with sets of numbers on them.
There's on sticker on the side that says:
37820-PT3-AO2
320-345935 and has an IPT Next to is is the date stamp JUL 24 '90
Found that it's for a '90 DX/LX Accord 5 speed


I know 37820-PT3-A21 (L21 is a California emissions ECU) is a for a 5 speed 1990 EX Accord. It's the computer I need.

[GXZ]

ok since the 90 & 91 lx have the f22a1 and the 90 & 91 ex have the f22a4, and since the only difference between the f22a1 & f22a4 is the exhaust manifold ( 4-1 vs 4-2-1) why would the ecus be different?

[lothian]

awesome resource. thanks for taking the initiative to compile this list.

so i have a question: what do the suffix codes represent that one sometimes sees printed on OEM ECU part id sticker?

for example, the ECU may appear with just the "37820-P8C-A53" part number; or, it may show the additional characters "SP", "SE" or "PE" and "SP" after the part number; or, there may be some other combination of characters.

what do these "suffix" characters, or lack there of represent within the ECU? we're not interested in speculation here. respond only if you genuinely know the answer, and include a link to your information.