jdm_ek4_hatch

Whats up peoples,im kind of stuck here i just bought a 94 EX eg coupe that came with a d15b. Im having problems trying to pass 5500 rpms,im redlineing at that point and i taught that motor could handle 6500 to 7000 rpms,but that's not happing. Vtec engages at 4500 rpms and just around the corner is 5500 rpms,so im like wtf...So i called my boy and he brings 3 different chipped p28's, with different programs skunk2,mugen,spoon. Plug them in test drove it, and i end up with the same thing cant go pass 5500 rpms.Vtec still engaged at 4500 rpms but just a lil bit harder though,and im also running a p28 in my car.So my boy say's that the motor probably came with a dx dizzy not the ex dizzy he said maybe because you are not redlining further because im not geeting enough spark he also said that my wiring could have a problem with it, i told him that im not throwing codes,and my oil is leveled.So what im asking is can anybody help me with my sisuation or if you expericend a problem like this before. Please help me out sought out the problem. Thanx

nicko360

is it bouncing off the rev limiter? maybe your tach is just broken?

jdm_ek4_hatch

Im not sure, everything works good, its just once it hits 5500 rpms the needle just hits it and bounces @ that 5500 rpms marker...And also when im runnin it, it feels like it could go further but just stops there at 5500 rpms. So you think the cluster could be broken or is there anything else i should check also???

Syndacate

Your boy is wrong, a DX dizzy won't bolt up to a JDM D15B.

At least I don't think it will .

Get a bone stock P28 and try that, no "base map" spoon, mugen, etc. - by the way you say those names "your boy" probably bought them off ebay with pre-made basemaps and they're worthless as **** on a bull.

Get a bone stock P28. If it still can't go past 5500 RPM then what's happening is your car is in deep **** and is throwing enough painful codes that it's kicking the ECU into limp mode.

jdm_ek4_hatch

Im not throwin no codes what so ever,but im goin to check to see if my p28 is bone stock or has programs??? Can i also use an stock gsr ecu???

Syndacate

No, don't use a GSR ECU.

Run a stock P28.

Stock = no programs outside the basemap.

jdm_ek4_hatch

I just remember that i did use a stock p28,that's my back-up ecu...Not the one running in the car now,the p28 that's in the car now came with it

Syndacate

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdm_ek4_hatch &raquo;</TD></TR><TR><TD CLASS="quote">I just remember that i did use a stock p28,that's my back-up ecu...Not the one running in the car now,the p28 that's in the car now came with it</TD></TR></TABLE>

A stock P28 ECU WILL ALWAYS redline at 7200 RPM. Either it's not stock or the engine is throwing enough codes to kick it into limp mode.

Either that or your engine is so messed up that it can't negotiate air/fuel past 5500 RPM.

muhaMan

my car does the SAME EXACT THING, but i still have a DX dizzy and im running the stock DX ECU.. you HAVE to get an EX dizzy/p28 if you want to rev up to 7200

Syndacate

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by muhaMan &raquo;</TD></TR><TR><TD CLASS="quote">my car does the SAME EXACT THING, but i still have a DX dizzy and im running the stock DX ECU.. you HAVE to get an EX dizzy/p28 if you want to rev up to 7200</TD></TR></TABLE>

I thought the '92-'95 EX and DX dizzies weren't interchangeable..?

sageuvagony

Does yours act like my car did a year ago?

Here's a vid. Yours may not be in limp mode but does it sound like this at 5,000 rpm?

http://www.youtube.com/watch?v=SCDrlCfFqqI

jdm_ek4_hatch

On that video it cant go pass 4000 rpms,and also that car is throwing codes,but im not throwing codes...So do you think i need to get an ex dizzy,or do you guys think my cluster could be broken,cuz when i start the car the cel comes on for like 3-5 seconds than does off,as should any car should do,im going to autozone later today to see if im throwing codes or not??? ill let u know the results

starcraftbw

it needs to be rebuild j/k. must be ecu problem

sageuvagony

from what I've read.. to do a mini me swap (dx head to ex head) the dizzy DOES have to be swapped out..

94c1v1cex

i had the same problem bro just let the car warm up for awhile and it'll be all good... it needs to be comletely warmed up or it will hit the limiter at 5500

muhaMan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate &raquo;</TD></TR><TR><TD CLASS="quote">I thought the '92-'95 EX and DX dizzies weren't interchangeable..?</TD></TR></TABLE>

na they are, when i got my z6 put in my car, i didnt have an EX dizzy so brother just cut a little piece off of the DX dizzy and it plugged right into my z6

BEYAAAH

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94c1v1cex &raquo;</TD></TR><TR><TD CLASS="quote">i had the same problem bro just let the car warm up for awhile and it'll be all good... it needs to be comletely warmed up or it will hit the limiter at 5500</TD></TR></TABLE>

The temp shouldn't limit the engine speed, only if VTEC engages or not

Imp-tuner

Well sometimes these are the main causes:

the speed sensor (VSS) in the transmission stop working 'cause is too old
The Oil pump ( if doesn't go above 20 psi does not activate)
The temp sensor (if the temp is the right one doesn't activate)

97Ej6mike

Which JDM D15b are you speaking of?

If its the OBD2 3-stage vtec, PM me, i can walk you thru all of your issues. Mine was doing that, it woudlnt rev over 5500 or so, just before VTEC engagment.

jdm_ek4_hatch

Nope obd1,would u by any chance know the problem for an obd1???

97Ej6mike

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdm_ek4_hatch &raquo;</TD></TR><TR><TD CLASS="quote">Nope obd1,would u by any chance know the problem for an obd1???</TD></TR></TABLE>

1.) The VTEC may not be grounded or wired correctly
2.) Limp mode, caused by too many CEL's or wrong ECU.
3.) Bad oil-pressure sensor connection (wiring harness)

I had issues with #1 and #3. Check to make sure everything is plugged in securly, and that the VTEC (if its wired by hand) is grounded properly. Sometimes if you buy a car thats already swapped, you dont know what engine harness the owner used before hand. If it didnt have VTEC, then it was obviosuly wired up by hand, which may mean he/she made a mistake while doing that.

h22aBB4

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BEYAAAH &raquo;</TD></TR><TR><TD CLASS="quote">

The temp shouldn't limit the engine speed, only if VTEC engages or not</TD></TR></TABLE>
in my prelude (p13) when it's not warmed up, it hits rev limiter at 6500 instead of 8k.

Also, I just got a civic EX with a CX (d15b8) swap, and I plan on swapping the head to an EX head. Right now, it wont go past 5500 rpm. When I do the head swap, will i have to switch the ECU from PO5 to P28, in order to go past 5500 RPM? Luckily it has the stock wiring harness, wired for VTEC

Joecivic94

Can i use my DX dizzy on my JDM D15b vtec head when i do my mini me? ill have a p28 ECU.

EGMikey

Hey i have the a similar problem... i just got a 95 HB cx with the d15b8... somehow its got a p28-a5 but it only gets to 5,500 rpm... but its not fuel cutting...any idea why? Also what b series ecu can i use on it?

HondaPartsHero

Use the correct ecu (P05) and your problem will most likely be fixed. You do not want to run a bseries ECU either.