Ok guys i know this isn't a all motor question per say but id rather ask here as i know alot of smart experienced people in here ...ok enough *** kissing ,i don't ask dumb question ...ill do every thing i can think of first .

now here we go ,

my wife has been driving the car cause our cavaqueer is on its last legs and i don't want here and the kids driving it far .

its been getting carboned up cause she a bit easier on it then i am ..so every few days i take it out and make it fast again ....did this about 3 time in 2- 3 weeks and it seemed to work fine (oh the car gets carboned up cause of my itb aren't fully tuned until i get my wide band ..but i know there runny safe just a little to rich )

So one day my wife come home and say the car was running great today, but after work it was running really bad . so i take it out and I've got a miss fire from 1000-to- 3000rpm and under load here and there through out the rev range ..vtec stutters and sounds bad ...........i think plugs right away due to the rich condition ..its obvious, but i cant get the ones i need cause its a long weekend up in Canada .

in the mean time i notice the car getting hard to start (low batt)i just put in a Odyssey race batt and its tiny ,so i track down that problem and find my alt connector (the 10mm nut for the direct feed to batt) it was very loose and has actually eaten almost all the way through the bolt due to the current the new batt sucks up (this is how they are so small since there really isn't a current limit to the amp's going into the batt,) it had magnetized metal fillings stuck around it and every thing had that electrical carbon all over everything .I sanded it all down and put a new nut on it (i have a diff alt to try but ill get to that later)...the problem cleared up and the car started to run better every time i got on it .

i did an oil change and some work on my ITB in the mean time ,the batt was charging great and had 14.5 at the batt with the car running . On the next drive the miss fire was back, and here's how the process went


one of my best skills is trouble shooting so when i cant figure something out i get very frustrated but here it goes


got new plugs ...still does it
replaces icm-still does it
replace internal coil-still dose it
change with know working dizzy-still does it
use cap and rotor/wires form know working dizzy -still does it
batt has 12.6 volts with out the motor running and i haven't tested it running yet but i will go and do that
check timing belt and TDC and its all good
comp test showed 230psi per
I've put some grounds on at the thermostat to batt/alt to chassie/dizzy to batt as well as the main ground from batt to tranny bracket thingy
ign timing is set at 15 base and then is sitting at 16.5 in the BIN
fuel pressure is steady at 40psi at idle and 45 at WOT...i did consider fuel delivery issue but its fairly random miss fires that are really dependable ....

so i took the car out around town with out beating on it (just after the new plugs went in i checked them and they were perfect tan )

after the city drive all 4 plugs were black except for a small spot on the porclin and tip of the electrode (this tells me its definitely a spark issue and not fuel related ). Now right away im tempted to burn a new leaned out chip to fix the problem but that wont help me figure out why its done it to begin with .

The plugs wiped of clean as the carbon was very dusty and not set into the new plugs .

the only thing i haven't done is to change the alt with the damage bolt(i think its the rectifier) with the other alt i have ....this may be the issue but it got dark and it was time to rest my brain

the fact that all4 plugs are carboned up rule outs syncing problems with the ITBS as they were all dead on with each other as well as on my bench syncer (shop vac and a vac guage lol ,they all came it at -6hg closed )

thats all i can think of right now ..sorry about the length but its all relivent to help diagnose this problem


thanks in advance

 

voltage was just tested runnign at the batt and at 750rpm it was 13.3 and around 1000rpm it was 14.2...so iguess alt/voltage problems is out of the question

is it possible for a eeprom to have issues? mabye its lost some of the bin i made ?
tomorrow ill reburn the same bin and see what happens

 

BFH's fix everything

 

A misfire is caused by an insufficient, incorrect, or total absence of:

- Compression
- Fuel
- Ignition

Maybe you just need tuning.

 

got fuel
got compression
i know its spark related but i think ive covered all the basics and then some ..got to be somthining im missing

 

Main relay, igniter!

 

never thought about mani relay ..hmmmm

and isnt the igniter the icm..or the liilt box beside the coil inside the distributer ?

 

oh and another thing ...the car seems to have a strong spark as i left a plug in the wire and ran the car ....nice blue/orange sparks that traveled an inch and a bit to the nearest ground ............any thoughts

 

up for any help

 

have u checked the injectors yet?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">oh and another thing ...the car seems to have a strong spark as i left a plug in the wire and ran the car ....nice blue/orange sparks that traveled an inch and a bit to the nearest ground ............any thoughts </TD></TR></TABLE>

Man if you have new plugs and known good wires, cap, rotor, coil, ignitor, distributor base, aaaand a good spark you can officially stop chasing your tail on the spark issue,lol. That covers your entire secondary ignition system end to end. I'm leaning towards an ECU/chip issue or wiring issue. You have really covered damn near everything. If an injector was going out wether it be failing open or closed it would be readable on the plugs if nothing else. Good luck man, I stared at this thread for a while scratching my head.

 

yea your probly right ..i was gonna reburn my chip tonight but my wife got back later then i thought and i got in relaxed mode lol

i guess i ll try ecu next ...if the chip doesnt fix it

i did take it out tonight and for the first 60 sec or so it was clean ..but not fast ..then it started up agaain


is it possible for a chip to change its programing .....

i had some bare iacv wires i hope they didnt touch

 

you let your wife drive your itb'ed euro r?? that must be love...

 

lol its my proof to there reliability...honestly it hurts me as my azenis ae already half gone and not to mention the mess thats in there from the kids ...were pretty broke right now but she WILL have a car soon ....

 

..well more work down the drain ..

burnt a new chip and still the same ..althoguh the plugs on the ecu were not in all the way (this fixed it for abut 2 min and then it started again )

replaced burn rectfier in alt and no go ..played with timming advance and retard....still there

rechecked tps voltage and i had to reenter it into crome and it help abit but the missfire is still there ....

there some wires that i can solder at the ecu just to be sure ..but that will be tomorrow ..

any other thoughts to help me through this tuff time

 

do you have datalogging?

 

no not yt ...im working on it and a wideband ...i know that fuel could be an issue here but i dont understand why all of a sudden it decids to do this ....

 

can anyone elaborate on the main relay ...whats is ourpose and functions ....is it a possibility ? or should i just leave it alone

 

The main relay is energized key on and after for the fuel pump. They fail but when they do it's completely, even on and off. Not a misfire situation.

 

well guys i some what figured it out

for what ever reason the bin i had been using for 3 months no longer does the trick

i did a retune and it works great again .....and its better on gas ..i did bump up fuel pressure from 40 to 45 and it helped alot to in the midrange ....

its weird but im happy its runing good aagain

thanks for the replies

 

seems the fuel pump might be to blame here

my fpr is almost all the way in and im can barley hit 50psi with vac

with vac off it jumps up to 60ish.....it does have 350 000 kilomters on it

could be why it was lean up top but i dont know why it would be rich down low ?

any thoughts

 

u can get a fuel pump from lightning motorsports ask for Tom for like 80 shipped ht members generally get free shipping

 

did the fuel pump and it ran great for about 3 hours ...then back to the stutter under load and even while at idle..i burned a new chip wiht a different low cam map and it ran great for about 10 min ..then back to normal crap again

 

check the fuel filter

 

already done last week .

thanks though