Alright, little background info... D16Z6 with Greddy SOHC kit, I ditched the bluebox and installed some DSM 450cc injectors and a VAFC in hopes of running the VAFC hack. I couldn't ever get it right and the car ran like ****. I figured maybe my VAFC was bad or my injectors weren't operating properly, so I took the VAFC out of the loop completely and rewired my ECU like stock, and put my stock injectors in. I still can't get the car to run right. I have on a few occasions seen a CEL 43 while cruising, which I'm told is related to a fouled O2 sensor.

The car surges while idling, the exhaust smells like fuel and the car shoots black soot all over the ground if I let it sit in one place running for more than a minute or so. It has hardly any power above about 4000 rpms and in fact almost sounds like it's detonating up top if I push it.

Anyway, I've put in new plugs and I took my O2 sensor out and cleaned it by burning all the black deposits off with a torch. Is this a pretty sure-fire way of cleaning the sensor, or should I just bite the bullet and replace it? It's 200 bucks from the dealership... maybe somebody here has a better deal for me. I tested my coil and igniter, and have verified that the timing is set correctly. I've tested the car with a friend's coil and igniter, and I also replaced the MAP sensor with one from a spare TB I had laying around. The car still runs like crap and I can't figure out why. It's got good spark, no misfires. No other related CEL's, and I've double and triple-checked all my ECU wiring. Could something like this be caused by a "fried" ECU?

The car is stock fuel-wise right now, I know it's not good to run it on the stock fuel system so I haven't really been driving it at all it's just sitting in my garage. Can anyone give me any ideas as to what I should check next or does anyone know what might be causing this? I'm getting frustrated, I've been without my car for two weeks now and I'm getting anxious to get it back on the road.


[Modified by M-EJ1, 8:05 PM 3/28/2003]


[Modified by M-EJ1, 8:06 PM 3/28/2003]

 

DSM injectors are HUGE....they need to be tuned down a LOT to prevent flooding...

 

The car no longer has DSM injectors on it. I guess maybe I wasn't so clear about that in my post. The car is back to a completely stock fuel system now and still runs like crap.

BTW, I know the DSM injectors need to be tuned way down... that's the point of the VAFC "hack"... large injectors, then limit the map signal way down so the ECU never realizes you have positive pressure under boost. Essentially you're fooling the ECU into leaning out to compensate for the size of the injectors.

Anyway though, enough of that. I know the DSM's are huge, that's not the problem.

 

Hmmm try plugging in another ecu maybe, or resetting the one you have in there now. You could also try advancing your timing a degree or two, just throwing out ideas meng.

 

Hmm... wish I knew of someone else around here with a P72 ECU I could borrow... would one from a DX or CX be plug-and-play? I know I won't have VTEC and such, but it could at least tell me if the ECU is bad or not.

I will try adding a little more timing tomorrow. It's at 16 degrees right now, which is stock.

 

Not sure if a non-vtec ecu will work or not...but try resetting the ecu, disconnect the battery for 15 seconds, then hook it back up...

 

i had the same setup. I took the turbo and everything off for emissions testing. When i took everything off, my car was running rich as hell and failed the smog test horribly. I looked around my engine bay and saw some vaccum lines weren't hooked up so i fixed them. I also checked to make sure the little rubber o ring for the map sensor didn't fall off when i was taking the missing link off, and sure enough, it wasn't there. So i replaced that o ring, hooked the vaccum lines back up, hooked some sensor back up on the back/driver side of the intake mani that was also just hanging loose for some reason, replaced the o2 sensor for good measure, and my car ran perfectly afterward. check all that stuff out.

 

oh, I also cleaned out my IAC valve. that solved the fucked up idle problem i also had. strange how with the turbo on, i never had any problems and then as soon as i take it off, all hell breaks loose.

 

its a sign.....

 

I would bet on your 02 sensor. It's more than likely it's fouled out if you were running pig rich... As for DSM injectors, my recommendation would be to use the E-manage and its injector correction factor (although my experience is mostly with WRX's lol).

Gary
http://www.gruppe-s.com


[Modified by Gruppe-S, 11:05 AM 3/30/2003]

 

Thanks everyone for all the suggestions. I did think maybe I had a vaccum leak so I checked all that, but the one thing I didn't check was the O-ring at the MAP sensor. I didn't realize there was even one there... maybe that's my problem.

Replacing the O2 sensor is kinda shitty, have to pay 200 bucks to the dealership, we'll see if the other stuff fixes it first. :\

Also, what should I do to clean the IACV? I've been told to take the charge pipe off of the throttle body and spray carb cleaner into the little chambers where the IACV is... does this sound right? It can't be taken off of my manifold, it's rivetted on, so I guess this would be the only way.

Again, thanks. I'll let everyone know if I'm succesful.

 

Fixed it.

You all have permission to laugh at me now. It was the little O-ring that goes in the groove and seals the MAP sensor connection. It wasn't there, I took it out a while back when I had a check valve setup running. All this time, it was a god damn vacuum leak.

My car has been sitting on jackstands in the garage for about 3 weeks now. I've gone over the timing multiple times, I ripped out my VAFC and DSM 450's and put everything back to stock, I went through three sets of plugs, had my distributor torn apart twice, put new wires, new cap, new rotor on, removed and inspected/cleaned the O2 sensor numerous times, I even checked to see if maybe my timing belt had slipped a tooth.

All that and it was a stupid O-ring.

I'm flabergasted and elated... my car is finally running right for the first time in... well... a long time.

Hip-hip-hooray.