vehicle: '95 LS, B&M FPR, DC header, 2.5" cat/exhaust, crower Stage III's, SFC
it all started yesterday morning when i turned up fuel pressure from 42 to 48 to get rid of a bogging spot in the rpm band, and my friend and i tuned down the rest of the map. most of the map was running about 12.5:1 a/f and it was happy. i drove it around for a while, and then went home. near my house, my car started sounding like it was running on 3 cylinders, only it wasn't missing much, if any, power. i took it really easy until i got home, turned the fuel pressure down to 42 again and switched fuel maps back, but still, even at idle, it was missing constantly. here's the stats i've checked so far:
resistance on all injectors is 11.2-11.6 ohms
compression is 160-165 on all four cylinders
fuel filter was replaced less than a year ago
no bubbles coming up in radiator neck
no apparent loss of oil
not burning more fuel than usual
no smoke out the tail pipe
plugs are gapped perfectly and are normal-looking
plug wires are all under 10,500 ohms
i drove it today after i pulled the plugs, and for about 1-2 minutes, it drove normally, but then it went back to missing at idle and under even the lightest of acceleration or load. if i just barely press the gas pedal, though, it runs even like normal. somebody please help me out. i have no clue what's going on here.


Modified by 95lstegman at 11:19 PM 12/24/2004

 

anybody?

 

back up to the top . . .

 

late night bump for "I'M TIRED OF HAVING A PRETTY, 8-STROKING METRO IN MY GARAGE!"

 

come guys. this is pathetic.

 

hmmm check for vacuum leaks yet?

any cel?

 

check the voltage output ... if its less then 14, you may get shitty idle .. also maybe time for a new distributor cap, rotor, coil pack, or maybe even a whole new dizzy...

 

i have the same exact problem, as stupid as it sounds i had my alternator rebuilt adn it fixed the problem! it sounds like yours is more on the mechanical side! good luck.

 

also, ignitor primary resistance is 0.7 ohms (spec is 0.6-0.8) and secondary is 16.4k ohms (spec is 13k-19k). i'll check the voltage later today when i check ignition timing. weather the past 3 days has been nothing but garbage. "winter" in FL is not supposed to be raining on and off all day and so foggy i can't see a fence 40ft. from my back windows in my house.

come to think of it, the alternator sounds like a perfect reason for this. that would explain why it doesn't do it for a while after startup and when i'm barely on the throttle. thanks! i knew somebody would come through!

 

okay, update time. i replaced the alternator. it got a hair better for a minute, now it's back to the same bull. went to autozone (took forever in only 4th gear!) and had the charging system checked out; it's fine. so it's not the belt slipping silently or something. and no CEL. i tightened down the injector rail, the t/b, and the IM, but it still does this stuff. i also reset the ignition timing, so that's not it either. and finally, i got 3 gallons of premium and a bottle of stuff that removes water and other impurities from gasoline, and ran it for a really long time, like 30 minutes, and even drove it a little, but to no avail. i'm starting to wonder though if maybe the rubber rings in the IM that accept the injectors aren't making a little leak or something. i have been reusing them a few times. . .

 

how long have you had 404's and are you sure its missing? ive heard those 404's at idle and they lope like a motherfuker... that might be it- youve checked everything... nd there is no loss of power, and when the gas is pressed everythings normal... maybe there is no problem..

 

I would replace those o rings for the injectors and to the fuel rail...thats makes a big difference actually

 

well, i put some goop in the o-rings and tightened the timing belt, and now it's a little better, so i think it's safe to assume it's one of those two things that is wrong. i'm going to pull the accessory belts today (hopefully) and the valve cover and upper timing cover and check that the timing is perfect, no tooth jumping or belt stretch or whatnot. at least that is free. and after that if it's not fixed, i'll get a set of CRV o-rings. i called acura, they don't have any in stock for my car, but i called honda with the p/n and asked if they'd convert it. turns out there is no honda equivalent; of all the B-series engines sold in US Hondas, like old prelude, CRV, and civic Si, none of them share this simple little grommet that goes in the manifold? but they all share the same P30 camshaft oil seal. interesting . . .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tegsallgood &raquo;</TD></TR><TR><TD CLASS="quote">how long have you had 404's and are you sure its missing? ive heard those 404's at idle and they lope like a motherfuker... that might be it- youve checked everything... nd there is no loss of power, and when the gas is pressed everythings normal... maybe there is no problem..</TD></TR></TABLE>

oh yeah, and it's missing throughout the driving range, from about 10% throttle to WOT, and at idle. no, i've had these cams for a while, and they idle fine with cam gears at (0,0) at 800rpm. i know what my car sounds like, and this isn't it. and it does lack power, but i can still get it down the road somewhat. and after the gasket maker around the bottom of the injectors and re-tightening the timing belt, it's gotten a little better. i can get a little more out of the gas pedal before it starts missing like crazy. it misses so bad, though, that it sounds like a harley.

 

okay, well, i've checked everything there is to check, and though i hate to spend $54 on stupid little o-rings, i think maybe, just maybe, after 175,300 miles, it may be time to put ALL new o-rings on the injectors. and maybe a prelude injector swap is in order as well . . .

 

175k miles?? has it has two new timing belts already? could just need a whole new belt, not just adjusting, especially with those stage IIIs.

 

it had a new belt at 150k, as well as lots of other tune-up goodies. and i think it got another new belt at ~160k-163k b/c of a water pump that failed after only ~10k miles, but the belt was changed anyways. so no, it's not old. and i replaced all the o-rings and such on the injectors to no avail. this is really pissing me off. i've looked over all the vacuum hoses and nothing jumps out at me. i'm wondering if maybe an injector could be having problems, but not all the time. is there something else i can check other than resistance? i don't want to keep spending money on things when i don't even know what the friggin' problem is. !*@^%$@#*%!$@^%!@*^$#!@&*^%!!!

 

okay, i went out and "listened" to the injectors with a screwdriver, and did abolutely nothing to the car. it hasn't missfired since! i swear i have no F'ing clue what made it want to be good, but i drove it around and the a/f was good, no hesitation, no missing, felt great. reminded me of why i'm so happy with the LS engine. only revving to 3000, it was strong and smooth. and it was good . . . and the fuel pressure is stil at 48psi, like what originally set this problem going. hopefully, it won't take a couple hours of running around town to start the problem up again. hopefully it never returns. pain in my @$$ . . .