When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
it's really hard to find case, i am going to give a gift for who solve the problem !!!
i have a misfire problem for almost 6 months in my 97 camaro and it made me really crazy
it have 50K miles on it
i think the problem starts when i used q16 fuel , but i am not sure
at the first it was a soft miss near 5700-6000 rpm at WOT , but now after few months its about 3500-end rpm and its very hard miss !
i,ve changed plugs and wires,checked for vaccum leak, ,tps, icm , opti , coil , fuel pump , fuel filter, air filter, ,cleaned MAF , unplugged MAF ,unplugged knock snesor ,checked injectors for leaking and spray , put washers between icm and head , new opti wiring , checked valve springs(with removing valve cover) , unplugged CKP , and using a scanner
i did some mods like removing egr ( just unplug and use bolt's on manifolds and removed the connections , but didn't remove the thing behind intake)
also removed cats , but they are for 4-5 months befroe miss
the scanner shows every thing normal
i had this errors before changing opti :
p0172
p0175
p0300
p0372
p0410
p0420
p0430
p0441
but after change , i have this:
p0300 random misfire
p1361
i do not have a fuel pressure gauge , but i don't think my problem related to fuel , cuse i am using a heavy fuel pump
the scanner shows:
28-48 advance degree , at WOT almost 28-36
long term fuel trim:
bank 1 = -11%
bank 2 = -6%
and show's nothing @ WOT
voltage = 12.8 - 13.8
water temp on scanner is ok
fuel regulator is not leaking
there was 2 ground for ecm harness near coil , i cleaned them , is there any more ecm related ground?
What do you think about crank sensor? somebody told not related and somebody said there was a misfire problem for them !
but when i unplugged that , there was no change
bring the GM coil and Icm back and again no change
today i removed all plugs again and there were good and brown
also checked wiring harness from ecm to icm and opti and there were fine
better to say , the car acting like faint at WOT and have BACKFIRE
i'm gonna check fuel pressure and cyl pressure soon
any suggestions ?? nobody had similar experience ?
unfortunately it's very hard to find chevrolet parts in my country , so your experience could help me alot ...
i've read all of misfiring theards in this forum , most of them had my problem but no body wrote the end of story
Usually spark plug wires can touch each other without problems as the insulation has to be good enough to prevent arching, especially to the metal parts of the engine.
Arching between wires seems unusual unless the wires are of very poor quality.
Your taping is likely to help.
You might also try reducing the spark plug gap as that should reduce the max voltage on the plug wires.
thank you !
i did something like photos to my wires , the car runs better now but still have the problem !
i am pretty sure my problem is my spark plug wires ,i also changed the spark plugs with ac-delco 41-943
now i am going to buy the stock ac delco spark plug wires
here is my questions :
1-is there any difference between corvette 92-96 or 94-95 camaro wires and my 1997 camaro wires? because i founded some spark plugs on ebay and they have different prices about 55$ to 130$
I rarely find ebay to have the best price on anything. When the price is much lower than other vendors, it is likely fake or a cheap clone. Fortunately most people on ebay are relatively honest - when they say "genuine" it is usually the real product and of course more expensive.
This site is mostly for LS engines and you have an LT engine. But perhaps someone with LT experience can answer your question.
How big a gap are you running on your spark plugs. If more than .040 you might try reducing it to that.
I rarely find ebay to have the best price on anything. When the price is much lower than other vendors, it is likely fake or a cheap clone. Fortunately most people on ebay are relatively honest - when they say "genuine" it is usually the real product and of course more expensive.
This site is mostly for LS engines and you have an LT engine. But perhaps someone with LT experience can answer your question.
How big a gap are you running on your spark plugs. If more than .040 you might try reducing it to that.
thanks again
you right about ebay !
i wonder why lt1 have this problem? other cars can use any spark plug wires and they touch ground and other wires and they have no problem ! but lt1 owners have this problem
recommended gap for lt1 is .050 but now i am on .040
after all , i've changed spark plug wires for 5th time and they didn't touch each other or body and engine !! still same problem... not any differences
i aslo have noise on my car radio and sounds like "tick" , this shows they are arcing
it should be something !!
opti => changed (challender)
ground wires => changed ( two big cable)
coil => changed (msd)
spark plug => changed 2 times (ac-delco 91-943)
spark plug wires => changed 5 times ( any brands included 7-8-10.5 mm )
so i changed coil + and - (green to orange - orange to green)
car runs very better now but still have the problem! on the 4.8k-5k rpm it has a hard misfire and after that to 6k rpm is soft misfire
could be coil related or something else?
Why don't you throw that ignition system away and go with the Cadillac North Star upgrade, far more reliable, every person I've known who's had an lt1 has had problems with the optispark. The cadillac upgrade can't be all that expensive and there's a write-up on here how to go about it. Just my 2💰
unfortunately i didn't know about the cadillac ignation system
do you have the address link for this swap? i did a search but found nothing
you think this is a better way? i am not going to keep the car for long time
today i was driving home and saw there is 200+ difference in rpm between scanner and tacho meter
rpm gauge reads correctly , but at the scanner it shows -200 rpm
today i was driving home and saw there is 200+ difference in rpm between scanner and tacho meter
rpm gauge reads correctly , but at the scanner it shows -200 rpm
what should it be? this could be the problem
Factory tachs are known for being unreliable. That's not the problem.
I think i finally found the problem
there are electrical noises from coil and they effect ecm parameters
in the misfire area they got worse
i don't know how to fix this ! please help me
as i said i changed sparks - plugs - coil few times , used 2 big cable from battery to ground and engine - used a big cable for + - checked and cleaned ecm grounds
You should be posting in the LT1 section, you'll get a lot better replies. Anyway, you say you are running the Chandler optispark?? That is widely regarded as a complete POS and known to cause issues like you experience. I would buy a REAL GM AC delco optispart or a MSD, unfortunately you have to pay to play with the LT1, optisparks suck in general but you need to buy a decent one for $400+ bottom line or upgrade to the 24x setup which cost a couple grand. Good luck!
so after couple months i just get rid of everything and swap a megasquirt
[/quote]
and new rims
Originally Posted by ahritchie
You should be posting in the LT1 section, you'll get a lot better replies. Anyway, you say you are running the Chandler optispark?? That is widely regarded as a complete POS and known to cause issues like you experience. I would buy a REAL GM AC delco optispart or a MSD, unfortunately you have to pay to play with the LT1, optisparks suck in general but you need to buy a decent one for $400+ bottom line or upgrade to the 24x setup which cost a couple grand. Good luck!
03-30-2015, 07:32 PM
my lt1 misfires like a boss !! 
[/quote]
