Hey guys, I finally got around to going MPFI on my STD Hatch. It runs great, not throwing any codes but.. it starts really, really rough. I got all my parts for the swap off my friends running Si. When it starts, it's almost like it's starting off 1 or 2 injectors. If I give it a little gas as it's stumbling to start it fires right up and runs just fine. I tried switching the two white wires on the dizzy, but that makes it not start at all. Any ideas?

The car is an 89 STD with swapped D15B2, MPFI parts from 91 CRX Si.

 

Been messing around with it, making sure all the connections are nice and, well, connected. The idle is kind of erratic from 1000-1500, I'm thinking the IACV is dirty or something. The one I put on was from a junk yard and I got it ~3 years ago, didn't even think to re-clean it before installing it. Once the car cools down I'll take it off for a nice cleaning. Any other input is much appreciated.

 

did you switch the two wires on the TPS?

 

Yes I did. Once it gets running, other than the idle, it's great. It doesn't bog at WOT at all, nice power from idle to redline, it's just starting and the idle that are off.

 

intake manifold gasket? throttle body gasket? FITV? IAC? try checkin all that and checking for vacuum leaks.

 

All new gaskets, no leaks. My IM doesn't have a FITV. I'll be trying a different IACV today, might be dirty or something. Would that be causing the rough starts? It stumbles and sometimes does a little backfire out of the intake. Thanks for the input xthekidx

 

hey men great proyect!!!

 

Heh, thanks. I cleaned my IACV, it was a little dirty. It idles a little better and doesn't stumble when I'm barely giving it gas anymore, but it still starts really rough. The idle is erratic at ~1100-1500 as well. Anyone have any other ideas? Pretty stumped and I have a big drive coming up in a few days, I'd hate to break down 700 miles away from home :S

 

my buddies ls does the same thing. if i were u, id try to get a iacv off a car u kno starts and idles correctly because the seals(fergot the "correct" term) only last so long clean or dirty. the only time this will cause problems is idle and starting up

remember the car is almost 20 years old

id also check the timing with a light but if ur sayin full power through the power band id doubt it.

 

The IACV came off a running car, all the parts did. I guess the IM was originally from an 88, and I'm not 100% sure the vacuum lines are right.



Don't mind the wires, I'm nowhere near done cleaning it up. Just making sure I get it running the way I want before I loom everything.

 

without an fitv its probably gonna be a pain in the *** when you start it.get a TB with a fitv and i bet it would run good on start up after that.

 

the 90 and 91 si's had one i thought???

 

Why though? The IM + ECU are from an 88 Si, which never had one. The car never had an issue starting up before.

 

fitv's were not available until 92. 88-91 civic/crx's only had iacv's, and you should have no trouble getting it to idle properly. assuming vaccum lines are all snug and routed properly, and no vac leaks. it is possible that the seal between the iacv and IM is leaking. i had to replace it because i was getting a surging idle after swapping to an xspower intake manifold.

 

i had the same problem when i did my obd-0 to obd-1 swap, IT DID THE EXACT SAME THING, try switching the plug in for the evap purge solenoid and the tps, i'm willing to bet money thats what it is

 

you mean the map and tps? both purge solenoids use 2 pin connectors not 3

 

I was thinking the same thing :S still stumped

 

i think it was the evap, but it could have been the map, it's the two that are the exact same plug-in i had mixed up

 

im glad my hf is already mpfi

 

Heh, yeah. My Civic has been in my family since day 1. I didn't mind the STD model until I started driving a lot more, the 4 speed was just ridiculous.

 

my crx is a 5 speed d15b6 mpfi insanley tall gears but it has some guts, i want to swap the tranny out to make it faster (THREAD JACKED!!!!))

 

Never! gl with the trans swap when you do it.

I still can't figure this starting/idle problem :S

 

get a crx or civic si tranny, the four speed is not geared for performance, neither is the dx 5speed
redlines:
1st: 30
2nd: 65
3rd: 75? it wouldn't rev higher than that for me
4th: 90? wouldn't go higher than 4500

 

i have a 91 civic si tranny.

 

Okay, back on topic. I re-cleaned my IACV and bled my radiator, still nothing. Was supposed to leave today