Ok, so my car has been running like crap the past few weeks. This has been an on-going problem, since before I installed the VAFC and DSM injectors, but I'm not so sure they don't have a hand in it as well.

Basically, the car is running extremely rich (I have a big long black streak in my driveway behind my tailpipe it's that bad). I have played with and tweaked the VAFC fuel correction settings until I'm blue in the face and I cannot make the car idle or run correctly. I know I really need to take it to a dyno to tune it, but as it is now I can't even drive it so I think there's something wrong other than just lack of tuning. The car feels sluggish and unresponsive, yet it detonates when I push it hard (even though it's running so rich).

I have been getting random code 43 CEL's while cruising and I was told this has something to do with a fouled O2 sensor, so I pulled that out and cleaned it by burning off all the deposits with a torch. Replaced it and the car still runs crappy. I pulled my plugs out and cleaned them as well because they were getting fouled. The car seemed to run a little better after this, but the plugs just foul right away. I'm running one step colder than stock NGK's gapped at .35. Is this too close for the stock ignition system?

Weeks ago I had checked my timing and it appeared to have been extremely advanced, past the last white mark, well above the 16 degree mark. I pulled it back down but that only seemed to make the car run worse. Now the idle surges and the car bogs when I step on the gas. I began to think maybe my timing belt had slipped, so I checked that tonight and everything lines up so that's not the problem.

While I checked the timing again tonight I also looked at the last code my ECU had saved and it was code 15, which translates to "Missing, defective or noisy Ignition Output Signal"... what does this mean?

Anyway, thanks for sticking with me if you read this far. I'm getting to my wit's end here. I'm about ready to take all the turbo parts off and pull the engine and just put a B16 in it or something.

Anyone have any suggestions? Where do I go next? I'm pondering pulling the injectors out and un-wiring the VAFC this weekend to see if that makes anything better, but I'd like to see if anyone else has any ideas before I go through all that work again.

 

Bump.. anyone?

 

Are you sure all the injectors are working properly? Maybe one is not firing? That might explain the detonation while still being rich. Try putting power directly to them and make sure they all click. Then maybe double check the wiring. Maybe one is clogged? When I switched to the hack one of my wiring connections broke while taping the harness up and I did not catch it. Needless to say my car ran like crap untill I figured it out.

 

Ok man, I'll check out the injectors and my wiring tonight. I soldered and taped all the connections, but maybe one of the injectors is dirty or clogged, or I messed something up when I wired them. Thanks for the reply.

 

Is this a new engine? When I put my engine in it wouldn't idle below 900 rpm and it smelled like gas real bad. I replaced the head gasket and all was better. But ya like said before check your wiring.

 

Nope, stock engine from 95. 120k miles almost. I'm going to do a compression check tonight as well and see if I get any abnormal numbers.

 

Ok, went and put my stock injectors back in and set my VAFC back to 0 fuel correction and the car STILL runs like ****. Big black sooty stripe behind my exhaust and a puddle of SOMETHING on the ground behind the exhaust... doesn't smell like gas, it's thin like water/condensation and smells like carbon/soot.

WTF is going on here?

Can anyone confirm or deny this: does the ECU advance the ignition to try to compensate for a rich condition? I didn't check the timing because after I started it up and found that it was still running shitty I just about threw some tools across the garage, so I figured I'd better stop for the night. I'm just wondering if maybe the reason the ignition was so far advanced was because the ECU detected such a rich condition and either advanced it intentionally or got confused, and now since I pulled it back from like 22 degrees to about 15 when it was running so rich, now it's really retarded. Does that make sense?

Anyone got any other ideas? What do I check next? I've got good spark, fuel is obviously flowing fine, all 4 injectors are firing correctly. My plugs are a little dirty, but nothing that would cause it to run this bad. ECU is wired correctly and I'm using the stock injectors and stock fuel map (no more correction with VAFC). The car is running nasty rich, the idle surges and my plugs and O2 sensor keep fouling. What the heck is going on?

 

I had a similar problem a little over a year ago with my v-afc, which I've long since ditched. Even when my fuel correction settings were at 0,0 my car ran and idles horribly. I isolated my problem to a defective or incompatible v-afc unit. Just setting the v-afc to 0,0 does not take it out of the loop as far as your car's ecu is concerned. In order to make sure your v-afc isn't causing a problem, you need to either remove it completely, or do what I did, which is to splice the MAP sensor wire at the v-afc so the signal does straight from the MAP sensor to the ecu (take the v-afc out of the loop). What I re-routed the MAP signal wire away from the v-afc, my car immediately ran fine, and I quickly removed and sold my v-afc. It's worth a try.

 

Vafc is meant to be adjusted on the dyno. Sometimes you can recieve decent results if you know the numbers that another engine close to the same as yours is using. Get it dyno'd and tuned.

 

I think you're missing the point here. I understand the need for dyno tuning with the VAFC. That's not the issue, the issue is that even when I make no corrections with the VAFC, the car still runs like ****.

In any case... here's the latest. I pulled the VAFC out (Nice to have a harness so I can easily pull it out), so now I'm running stock everything. Stock injectors, stock fuel maps, I've reset the ECU and tried idling it 'til it was warm in hopes that it would "learn" what it needed to do, with no results.

After this I decided to check the timing again, and much to my surprise, the spark seems to cut out every once in a while now. I hooked the timing light up to plug wire one and got a good connection at the battery terminals, then pulled the trigger... it goes along well for a few fires then it has a hiccup and I see no spark, the motor burbles a little..

So in other words, I have a misfire now where I didn't before. It drops the spark randomly on all the cylinders. WTF?

Took apart the distributor and pulled the rotor and leak cover and tested the coil. I get 0.001 resistance when I test it on the positive and negative terminals with an ohm meter. This does not sound right, my chiltons manual says there should be 0.6-0.8 ohms of resistance. Am I crazy or am I not doing this right? If the coil is burnt, the car wouldn't run at all would it?

 

Ok, I'm a dope and I didn't know how to operate my voltmeter. I figured it out and tested out my coil again... i get 0.9 ohms resistance on the primary, and somewhere in the range of 15,000 ohms on the secondary winding.

According to my chiltons manual the primary should be between 0.6-0.8 for the primary and 12k-19k for the secondary. Looks like the secondary is right smack dab in the middle of the specs, while the primary is off... could this be the cause of my problems? Keep in mind I only lose spark sometimes, so I'm thinking maybe a minor amount of extra resistance in the coil could cause this? If there's too much resistance, then the spark I'm getting would be weak, and it may not fire at all sometimes... which seems to be the problem.

My other option is the ICM (aka "igniter"), which I'd have to pull the whole distributor to get at apparently. I was under the impression that if the igniter went bad it was an all or nothing, but maybe not?


[Modified by M-EJ1, 10:36 PM 3/22/2003]

 

If the coil tests out of spec, replace it. Check to make sure the wire connectors on the igniter are tight. Did you do that compression test?

 

I have a friend who will be letting me borrow his coil today to see if it improves anything. I may be able to test with his igniter as well if the removal is not too involved. The wire connectors on the bottom of the distributor (there's three) which are connected to the igniter were all nice and tight.

I have not done the compression test yet, I will be doing that today when I have that same friend over to help me.

 

did you install it backwards? i did that, i had the power hooked upto the no 2 injector, made it run rich like a **** and my car wouldn't idle. also try initalizing it.


[Modified by altoid, 3:54 PM 3/23/2003]

 

Ok, this is getting seriously ridiculous. Tested with a known-good coil and igniter and it still runs like crap. I did a compression check and it comes up even across the board. I hooked up the timing light to my friend's car and observed it as I pulled the trigger and he gets nice "hot" sparks and never has any hiccups... where as when I hook mine up, the spark seems slow and weak and sometimes doesn't fire at all.

What the heck is going on here? Are there any other items that control the spark that I should be looking at? I've replaced the plugs twice already and it still runs like ****. My current set is a little fouled, but not incredibly so. Would fouled plugs cause it to misfire every once in a while, and would the misfire show up with the timing light when that happened?

I'm grasping at straws here. Maybe it's the ECU? Could a "fried" ECU cause the car to run like this, or would it be an all or nothing situation?

 

here is what i would do make sure any wires that you used for the vafc have been wrapped and are not or didnt ground out anywhere. Also make sure the plug wires are good. If not go ahead and swap computers doesnt hurt to try. other than that might just be distributor. thats all i can think of keep us updated hope you get it working.

 

Permission to laugh at me is granted. It was a vaccum leak. I forgot to put the little O-ring that seals the MAP sensor connection back on the throttle body after I took the check valves off. Car is running much better now.

Oh well, at least now I know how to take apart and put back together a D-series distributor in short order.

 

**** dude, that sucks...I just read all this to try and figure out what your prob is it really seemed like it wasn't a problem with spark or fuel (since you put the stockers back in) so a vaccum leak was a good candidate. mystery problems suck

 

HAHA!

keep us updated when you put the vafc and the injectors back. by the way, are you using the blue top injectors or the black top? and also, are you using stock honda resistor boxes or resistors from radioshack?

 

Got everything re-installed and it runs decent enough now. See this thread for some of my nit-picks on the VAFC hack: https://honda-tech.com/zerothread?id=463419

Overall though I'm happy, at least I can drive my car now.

BTW, I'm using bluetop injectors with a CRX resistor box. However, after doing some research, I've found that the problems I'm experiencing related to hard starts and bucking COULD be related to different variations even within the bluetop injectors as far as resistance goes. I need to test mine, because from what others have said some are 6 ohms apparantley and some are 2 ohms or something like that. I'm going to test mine and get the right right resistors hooked up to make it the correct resistance and see if that helps at all.