question

[91civicDXdude]

your DX cut out at 6800 rpm. your tachometer was off. there is no variation in ROM programming in honda ECUs. it is hard coded as one variable and one variable only.

Also, on a compression test, to get more accurate results, remove the fuel pump fuse and hold the accelerator to the floor. this is so the throttle stays open and more air gets in so the test doesnt take as long and will be more accurate to real conditions. make sure the engine is warm also.

[bambam89lx]

88-91DX
88-91LX D15B2 1493cc
4 cyl, 16valve
SOHC
9.2:1 c.r
92 bhp @ 6000
Redline: 6800 rpm
89 lb-ft @ 4500

88-91Si D16A6 1590cc
4 cyl, 16valve
SOHC
9.1:1 c.r.
108 bhp @ 6000
Redline: 7100 rpm
100 lb-ft @ 5000

That information was taken directly from 4thgenerationcivic.com.

There IS a difference between the si and the dx. Also, redline is different than the fuel cut off. My car redlines at 7100 and cuts off at 7500. My dx used to redline at 6800 and cut off at or around 7200.

[91civicDXdude]

again, you are wrong sir.

the DX ECU PM5 has a fuel cut set in the ECU's memory @ 6800 rpm. the "redline" is only the red line on the tach, which is 6500 for all models except for HF that have a factory tachometer.

the Si 90-91 PM6 ECU has a fuel cut @ 7414 rpm, but most often times is represented by 7200 rpm on the factory tachometer.

this was taken from the good folks @ pgmfi.org, reverse engineering honda ECU's tends to tell you the actual value, not something somebody heard or read on a website.

by saying there is no variation in honda rom's, i meant per ECU. all PM5 ECU's are identical etc.

[outofstep]

so are u guys thinking its my ecu then? as for the compression, test what am i lookin for, and say its not right, what does that mean? thanks for all ur help guys!

[91civichatch2571]

If the tests were low, you would most likely benefit a lot from a set of piston rings and may even find out that you have a bad piston. Or you could do a leakdown test, It tells you a lot about your engine actually. Shows if you have bad valve seals, head gasket, and/or rings, look into it...

[90civicracer]

Yeop my car is one that cuts off at 7414...almost up to 7500.

[outofstep]

well its a new motor, and they claimed a leakdown test was done. i believe i mean dont get me wrong the car is quick like once its going its fast it just seems to bog on on tourqe

[outofstep]

has anyone else done this swap, what ecu did u go with and what do u think about this motor compared to an si motor

[erastusboy]

i thought the d15's were the 64 hp engines in the hfs im so confused now

[90civicracer]

d15b2 is the engine that is in dx and lx cars which is 92hp...and i think d15b1(???) is the one in the hf. If u check up under the frequently asked questions thread at the top i think it has all that stuff in there.

[outofstep]

d15b is a jdm civic vti motor sohc vtec
i changed the fuel filter today since it been a while, but that didnt really do much. i was reading up on it and i think it may have 2 vtec switches... i have one hooked up to my vafc2, perhaps the 2nd isnt hookups up, yo kris where u at ur a pro with this swap

[outofstep]

http://asia.vtec.net/article/d15b/

[outofstep]

hasnt anyone on this forum ran this swap besides me???

[4G4D Store]

What are the specs on the jdm d15b? Are they as good as the Si bottom end?? I'd almost say that's what's holding you back - the Si bottom end has more torque, - your both running intake header and exhaust with Si ECU. I don't know if the vtec head would give you that much more advantage on the 1.5l block compared to his 1.6l block. But I don't know the specs on the jdm d15b either - I'm prolly thinking the the stock d15b2 with 92 horse.

[90civicracer]

Looking at the 4th gen FAQ sticky thread it says the jdm d15 has 125-130hp.