OK long story short i just bought a 1990 CRX HF with a d15b7 motor and an SI tranny. The car idle's up and down, like the IACV was acting up, this isn't my first Honda. Well i tried some used one's because new is like 2 bills so i have a d15b7 motor intake so i used that one but it dosen't bolt up so i left the HF one bloted up and Pluged in the d15b7 one and the car starts better i jus have to apply some gas or it stalls, then it idles fine tell it warms up the idles up and down and runs bad...Could it be timing or i duno!HELP

 

What? I don't understand what you are asking. Why not use punctuation? -Sorry

 

What have you tried so far? O2 sensor? Maybe the Ecu? Sounds like the air temperature sensors could be the problem though.

 

I would like to help, but first you need to edit your post. I barely understood anything you said.

 

Did you already check your vacuum lines?...or, they might have the plugs in the wrong sensor.
Im not sure what the sensors are called, but one of them is the iacv and another on the top of the intake manifold. whatever it is, theres two plugs that are the same, so check that out.

 

FIXED FIRST POST.

 

i need help

 

ok, that's not really fixed. Still don't understand. Copy and paste this with your information and somebody might try helping.


engine code:
intake manifold used:
injectors used:
ecu used:
distributer used:
wiring modifications done if any:
problem:

I have a feeling you have a case of mis-matched ecu/dist/injectors. If you're using the d15b7 intake manifold, you need to put peak hold type injectors into that manifold. d15b7 are saturated type injectors wont work with 88-91 mpfi car because its wired for peak hold. You need injectors from 88-91 civic or crx si/ civic wagon 4wd, 90-91 integra, 92-96 prelude, 90-95 accord just to name a few that would work fine. You should be using an 88-91 crx si ecu (best choice to make it run decent anyway) and you should be using the original HF distributor because HF dist=Si dist So your for this set up to be functional it should look like this.

1990 CRX HF with:
engine code:D15b7
intake manifold: D15b7
injectors: 88-91 crx si PM6
ecu:88-91 crx si PM6
distributer used:88-91 crx si or crx hf (same thing)
wiring modifications done if any: none

 

you could run obd1 injectors you just need to do the resistor box mod. a vacum leak could make your idle go up and down.

 

Ok now im not trying to be a d*ck or anything but do you realize you used d15b7 every time...You bought the HF with a motor (d15b7) removed the IACV, then the HF d15b7 IACV but wouldn't bolt up...Then you decided to leave the original HF (d15b7) on there...


Did you do anything at all? There the exact same thing...I want some of what your smoking...

 

Hahaha.
At least notice where punctuation marks are needed. Otherwise we CANNOT help you.


ps don't worry I fixed your post too.

 

iacv and iat are switched!

 

damn the hate

 

engine code: none
intake manifold used: 1990 CRX HF
injectors used: 1990 CRX HF
ecu used: 1989 CRX SI
distributer used:1989 CRX SI or HF
wiring modifications done if any:none
problem: car warms up the idles up and down sometimes alil black smoke out the tail pipe. Have a IACV from a d15b7 intake pluged in and hanging because the bolt pattern is alil dirffert. Help i know i eglish is bad sorry..

 

i thought the plugs could be switched because there the same plug, and wire color. so i tried and no help.

 

First things first, I'd get rid of that HF intake manifold. Heres the why... HF manifold is TINY, it has a throttle body the size of a small redbull can, the plenum is tiny, the runners are tiny. I would say the ports are atleast 4mm smaller all the way around vs. the ports in a d15b7 head. D15b6 HF engine is an 8valve engine that cannot (litterally cannot, even with limit removed) rev past 5,500rpm, D15b7 is a 1.5 as well, but higher compression, 16v, and designed to rev to about 7,000rpm. I think it's a fair asumption that an HF manifold is flowing more air than ever intended by the time you reach 3,000 rpm. Black smoke could be the dead give away that the engine is starving for air. Get a d16a6, d15b7, d16z6 intake manifold on there to eliminate the obvious, and go from there. Either way, this will allow you to have an iacv correctly mounted and plugged in and should get you much closer to having it running decent . Also make sure you don't have your IAT and IACV plugs switched, the plug is the same, it's a common mistake and will make your car run like caca.

 

thanks for the info. I have an 89 CRX SI Intake will that work, what about the wring and vac lines since its a HF wring harrans. And the d15b7 motor has an EGR my Si dosen't have one? And will a d15b7 intake wire up? thank a bunch

 

And the shifter is real loose slopie does it need new bushings or someting i hace a DC short shifter but it came with no bushing kit

 

If you're using an si ecu, then your egr isn't doing anything already. Hf engine harness is the same as an si other than the egr. Use the si. Vacum lines are no different than how they are right now. After putting on the si manifold make sure there are no air bubbles in the coolant system, these air bubbles are often over looked and a coomon cause for surfing idle.

 

whaa? yu speld shizz al rong. maybe take a look under the car at the shifter and check for loose bolts. like the one that holds the shifter on the linkage

 

updates? did this solve the issue?

 

Well i thought about it and, if a shad-tree mechanic did the swap then they probably didn't changed the intake gasket maybe left the old one on. So i replaced it early today and the same thing. It runs pretty good with alil high idle then when it warms up to about 1/4 way it starts going up and down"the idle" ****. I have a iacv from a D15b7 motor pluged in and hanging there and the hf iacv bolted to the intake. I think i might try an used iacv i guess if i can find a good one, because a new one is 2 bills so i don't know if i'm willing to take that gamble yet becaue i don't think i can return it, because it elc. , i think. Any ideas???? i jus don't get it

 

is there any way to bypass the iacv??

 

i'm trying the SI INtake in the A.M.Thank for the input