I posted this on T-I, but haven't gotten any responses.... let's see what good ol' H-T has to offer! Sorry this is so long, but I tried to make it as short as possible while still covering everything.

I have Crower 403 cams for my LS, it ran rich at idle like those cams always do until I dyno-tuned it, which got rid of my Code 45 too rich/lean, gas smell at idle, missing at low rpm, and stalling in parking situations during hot weather, which was the only time it ever stalled. From the dyno time on, for over 6 months it ran without a CEL, without smelling rich, without even thinking about stalling. Beautiful.

Then at the end of April (on my birthday), I started hearing a very noticeable ticking sound at all rpm. Took it to Acura for a valve adjustment because that's what it sounded like, and they give it back to me and the car ran much worse. The CEL came on while they were pulling the car in with an engine misfire code, and the thing just ran pretty crappy, stalled, put out a lot of white smoke all the time, etc. Had Acura do a compression test and it came out 195/195/180/195, not bad. Took it away from them (they tried to screw me in so many ways, but I won't get into that), and it ran the same crappy way. It ended up being a terrible tank of gas as far as I could tell, because the problem (ticking, smoke, bad performance) gradually diminished at the end of that tank and through the start of the next tank. It's run much better ever since with no white smoke.

The problem ever since has been that I get CELs 71-74 for random engine misfire on all four cylinders. I don't hear knocking, but I guess I've never heard it before so I might not know if it happened. Changing fuel at 1000rpm with the S-AFC has little/no effect.
Symptoms:
1. Stalling in parking lot situations and a lower/less steady idle than usual, even with the cams (remember it idled fine for 6 months)
2. Smells like gas at idle
3. Takes some cranking to start, then kinda coughs to life
4. Occasionally quite a bit of moisture in the tailpipe at idle, little droplets on the inside of the exhaust tip. Never happened before bad tank of gas.
5. Hesitation/missing at low rpm and light load (like 5% throttle, 1300rpm in 2nd gear in a parking lot). Moderate/heavy load at low rpm isn't a problem.

After resetting the ECU the CEL comes on after a few minutes to an hour of driving. First are always cylinder #2 and #4, then eventually #1 and #3 join in the fun...

The car runs great above 2k rpm all the way to redline and from 0-100% throttle, but low revs and light throttle and idle it runs rough, stinky, and unsteady. Runs a lot like how it ran when it used to run rich at idle before dyno tuning, but I'm getting misfire codes now while I got too rich/lean codes before (not anymore). Stalls most in stop/go or coming up to a stoplight, something about short periods (a couple seconds) of low rpm/moderate load make it unsteady just like when it used to run rich before tuning. It'll drop down and either stall or drop really low then sputter back to life, go up and down (only up to about 1k) and eventually even out to 650-750rpm. I've spent the past couple of months troubleshooting the problem with my Helm's manual. Here is the checklist they have for random misfires, and why it doesn't seem like the cause:
1. "Fuel pump insufficient pressure, amount of flow."
My FP gauge reads 40, 42, 44psi, whatever I set it at. Hasn't changed. Plus still runs well at mid-high rpm.
2. "Fuel line clogging, blockage, leakage."
Don't think so for same reason as above, it doesn't feel like it runs lean at higher rpm. I had the injectors ultrasonically cleaned, they said the flow rates were ok but the spray patterns were off to the side. Thought that would solve the problem but it did almost nothing.
3. "Fuel filter clogging."
Just changed it, at the same time as reinstalling the injectors.
4. "Fuel pressure regulator stuck open."
See #1 and #2.
5. "Distributor malfunction."
Replaced cap/rotor/wires/plugs (plugs 3 times) with no change. Plug #2 after a few days gets fairly dry-fouled as if it were running rich, that is the one cylinder that had slightly off compression. But it doesn't run any better with brand new plugs.
6. "Ignition coil wire open, leakage."
Tested resistance, OK.
7. "Ignition control module malfunction."
Tested, seemed ok. Also looked at main relay, OK.
8. "Valves carbon deposit."
Can't really say I know. How would you clean that?
9. "Compression low."
Tested, 195/195/180/195.
10. "IAC valve malfunction."
Couldn't figure out what I was doing wrong for testing the circuit, but when I pulled the 2P connector it stalled, so it works. Also my idle isn't high at all, so this and a vacuum leak are pretty much out of the question. I think....??
11. "Fast idle thermo valve malfunction."
This is just on A/T cars right? Even still, once my car starts when cold it does go up to the 1650rpm or so that it should.
12. "Fuel does not meet Owner's Manual spec, lack of fuel."
Filled up at various stations, always with 92 octane. No change.
13. "VTEC system malfunction."
No VTEC!

Also for low-rpm and load misfires, the Helm's lists, in order:
1. IAC valve (mentioned before)
2. VTEC system (no VTEC)
3. Fuel pressure (mentioned before)
4. Valve clearance (checked and re-adjusted myself, very little change. Tried Crower and stock lash settings, little change also).

One thing I should probably mention is that I got an 8.5lb flywheel a week before the problem started (well, the bad tank of gas). The car ran fine but did dip as low as 500rpm for a second once in a while (when the engine was coming down to idle in neutral), just because the light FW made revs fall right past normal idle. But it always popped right back up to 750rpm.

The thing is, with the cams it idles worse in hot weather, and the 6 months where my car ran fine were Nov.-Apr., and after the flywheel and bad tank of gas it's been 70-95 degrees every day. *Maybe* this is just the way my car idles with the lighter flywheel in hot weather, but I really doubt it because I'm getting misfires in all four cylinders and it did run fine for 500 miles with the new flywheel, before I got that tank of gas. I dunno though, maybe the hot weather and flywheel's effect on the idle, set off my crankshaft fluctuation sensor, but would that cause the symptoms I'm having? And how would I fix that problem?

PLEASE help guys, this car problem has been eating up all my spare time and money in the past few months and honestly is really disrupting my normal life. Oh and I also found out yesterday that I have an emissions test soon, so there's even a deadline now for fixing this stuff. Bottom line: I NEED YOU GUYS!! Please help however you can. Thanks.

 

I know you had problems with your cam timing. Did you check that? Timing is the best place to start with these type of problems.

From what you describe, I can tell you have one or more of these problems.
1) ignition timing off
2) lack of compression
3) cam timing off

In my opinion, you should eliminate as much as possible before you start to do electrical trouble shooting.

 

Ignition timing is fine, cam timing was fine before but haven't checked it recently, I'll definitely check that. Compression test turned out 195/195/180/195 so I don't think it's that. Thanks bud.

 

Could it be your fuel system (injectors, rail, filter, pump) is screwed up after bad gas?


Oh, I read more of your post and see you've dismissed this. Still, since all your problems started after bad gas and half the attributable causes are fuel related, I suggest you're overlooking the obvious.

Replace injectors? Cleaning something that may have been corroded doesn't really solve the problem and they guys who did it said they spray abnormally, right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by White98LS &raquo;</TD></TR><TR><TD CLASS="quote">Ignition timing is fine, cam timing was fine before but haven't checked it recently, I'll definitely check that. Compression test turned out 195/195/180/195 so I don't think it's that. Thanks bud.</TD></TR></TABLE>

Well if your ignition timing is on, you cam timing must be on too. I think it's a good idea to bring back the cam gears to 0 when adj. valve lash. Even if you didn't I don't think that would be the cause of the problems.

I think it's safe to say you can narrow it down to an electrical problem. Did you ever try to unhook the AFC to see if the problems went away? If not, you might want to try that.

If you could, swap the distributor with another on hand. I'll try to look into the Helms when I get a chance to see if I can help any further.

good luck

 

Well they said my injectors used to spray off to the side, now they're fine I'm pretty sure, if they weren't they woulda told me... they're probably the best fuel injector/carb place in the state. It's weird because if a line or the fuel rail or something was clogged, wouldn't it run shitty at all rpm and not just idle/really low rpm? And wouldn't it affect fuel pressure? My FP is fine (I have a gauge to go with my adjustable regulator).

The distributor swap is a good idea, I need to find a friend with an OBDII right? GS-R/LS won't matter, correct? How about auto/man? These must sound like dumb questions but I just got off work!

I did try unhooking the S-AFC, it was a while ago but I remember it ran pretty bad, it was kinda hard to say because it was already running badly. But I'm almost positive the S-AFC is working because those cams require a funky fuel map and it would run a lot worse if the S-AFC just wasn't working. I've also changed fuel pressures and counteracted the changes with proportional S-AFC setting changes, and it drove the same.

Checked the cam gears, they were fine. I'm about to set them back to 0,0 (they are at +2, -2 now) and see what happens, also will probably set ignition timing back to 16 deg. Then I'm going to spray the TB again with cleaner really well, and reset the ECU. If none of that works, I'll raise the idle just for safety's sake - today goin about 40mph downhill it stalled so I lost my power brakes, scary.

I'll update in a couple hours after I do that stuff I listed above, probably won't get a chance to swap distributors until next week though, got a 48-hr. work week dammit. Thanks guys, keep any more ideas flowing! I guess a guy on T-I is having a problem almost exactly like mine.

Hey, since I've already run regular Gumout fuel injector cleaner and cleaned my injectors plus replaced my fuel filter, is there any sort of insanely, intensely powerful fuel system cleaner I can pop in my tank to completely annihilate anything in my fuel system?


Modified by White98LS at 6:14 AM 7/31/2003

 

hey, this happened in my friends hatch, it has a 98 b18c5, his fuel pressure was at 40 something, we thought it was fine, had a valve adjustment done etc, compression check, electrical check, finally brought it to a friend of ours house who was home from college, he looked at it, drove it, popped the hood, and set the fuel pressure to about 52-55, problem solved, runs great since, so if your bored, try that i guess, i know its two different motors, but give it a shot

 

Hey thanks, sure I'll try it! The only reason I wouldn't is the cams run quite rich at idle even on stock fuel pressure. I use the S-AFC to lean it out at idle, but from what I've heard the S-AFC is only effective up to a certain percentage up or down (I've heard about 14% but it seems to work past that point for me), so going crazy on the FP would make my idle quite rich (theoretically). But I'll totally try it. I also don't want to blow my already taxed fuel pump, LS pumps are way lower-capacity than GS-Rs unfortunately.

 

very true, but give it a shot, worked for my friend, try getting yours to like 48-50 if you dont want to max it

 

Alright, 48-50, sounds good. I've run 44psi just fine, so I'll try a little more.

 

yea if it wasnt so late, id go check mine, but its dark and i live near the woods, and i dont wanna get eaten, lol, i think mine is in the 48-50 range

 

Well I cleaned the TB ports again, nothing, I tried covering the upper port at idle and it shut off just like it's supposed to. I brought the exh. cam back to 0, little change.

I raised the FP to 46psi but the car ran about the same, if not slightly worse. Truth is, I've had FP at 40psi with -22% on the S-AFC, all the way to 46psi and -18% on the S-AFC, no matter what it still smells like gas (hard to say if it's rich or lean though, I guess lean smells like gas too), still stalls in the same way with about the same frequency. The puzzling thing is it holds that fairly steady (I have cams remember) at 750rpm, but if I rev it up a little bit like just parking or something or letting the revs down coming to a stop, it falls right past 750 and drops way down, then coughs back up... It did this a bit sometimes after I got the flywheel, but not this much and it didn't stall or smell bad.

 

Do you guys know if VTEC and non-VTEC distributors are compatible? And is the crankshaft fluctuation sensor the only difference between OBDI and OBDII distributors? So the ICM/ignitor and coil should be the same regardless of OBDI/OBDII?

 

Just an update:

Two nights ago I set everything back to what I had after dyno tuning plus 1-2psi of fuel pressure, then raised the idle to about 900rpm. The car has idled great ever since and doesn't even think about stalling.

BUT again after 45 minutes or so after resetting the ECU, the CEL came on with misfires in 2 and 4, 1 and 3 will surely follow soon. God dammmit. Still runs great except for a bit of missing/jerking at low revs at low throttle. So I have to wait until next week for my friend to get back so we can swap out his distributor with mine.

 

I'm having similar problems in my 99 accord 2.3 I jumped the gun a bit with an educated guess and replaced my fuel pressure regulator. I was 200 miles from home with 2 kids and a bit worried it seemed to help some but the problem is still there. I'm going to check fuel injectors now that I'm home at the shop but I haven't had a chance to go threw farther testing with it because we just got home. I hope you figure it out soon I know it's driving me nuts!!!!

 

A 9 year old thread? Seriously? It's always a noob too...

 

LOL I like how he hoped that his problem was fixed soon.

If he didn't fix it by now I'd be worried.

 

well I think it's safe to say I didn't know there was a time stamp on it but hey learned somthing new

 

did u ever fogure this out? Just seen this i know its old as F but sounded familiar so figured id ask Why do you run 92 Octane ?
idk about u but i used to try once a week or so to run 89 atleast sometimes 92 in any vehicle i owned. My logic was that like anything else in life 92 is fancy and u use it if u can afford it.
Well come to find out after my 3rd vehcile that year having cat issues that using octane booster and 92 octane fuel is not being nice to ur vehicle but actually clogging the cat.
MAybe this applys to ur situation maybe not lmk what u think?