Impala Forums banner

1 - 13 of 13 Posts
G

·
Discussion Starter · #1 ·
i have a 1994 firebird forumla with a six speed. After a minute or two the engine will begin to stumble really bad, if i push the throttle to the floor it will open up and run, but from 1000 to 3500 rpm it stumbles. I checked the fuel pressure and it's running at 35 psi, which is almost ten under normal. Also the the spark plug wires are arcing to the head, but i've replaced all the wires, and i check them all the time to see if the headers have burned them. I've had the module on the coil checked, and it was fine. I checked around the coil and there's no evidence of it arcing. I also checked the fuel filter, and it checked out as well. Everything seems to be in order, but even after changing spark plugs and wires it still arcs. I've read alot about the optisparks going out, and the symptoms seem alot like what i've experienced, but i wanted to make absolutely sure before i go taking the water pump and all that crap off, but i would really appreciate some help with this.
.... and yes, lt1's came in 1994, they actually came out in 1993, at least to the f-bodies *camaro's and firebirds*
 
G

·
Discussion Starter · #2 ·
LT -1 in a 1194...I doubt it if it's true it is not the orginal engine...anyway if you are still acrhing around the heads chances are you've broked the insulator on one or two of the "new" plugs
 

·
Banned
Joined
·
3,667 Posts
LT -1 in a 1194...I doubt it if it's true it is not the orginal engine...anyway if you are still acrhing around the heads chances are you've broked the insulator on one or two of the "new" plugs

Not sure where you get your info but you obviously dont know much. LT-1 engine were around in 1994, not only in F bodies but in impala,caprice,buicks,caddy's and so forth. With that aside, the problems def. sound opti related. Pull the coil wire off the opti (behind the water pump) and look in there with a flashlight and see if you notice any moisture or any type of color or build up in there.

You are likely going to have to remove the opti and replace at the very minimum the cap and rotor, making sure when you take it apart to check the black module to make sure there is no oil or condensation in/on it. Contrary to popular belief, the opti is not a big deal to replace.
 

·
Registered
Joined
·
2,102 Posts
I'm kinda leaning towards an O2 sensor going south. If it acts up only once it starts to warm up. Cold, the O2 is not being used, nor is it at WOT from what I understand. Your arcing plugs could be wires are not on tight, cheap wires, cracked plugs (as mentioned before). No check engine light? Do you have a code reader?
 

·
Registered
Joined
·
15 Posts
Hey, man did you ever figure out what was wrong with your vehicle. I'm having similiar issues.

i have a 1994 firebird forumla with a six speed. After a minute or two the engine will begin to stumble really bad, if i push the throttle to the floor it will open up and run, but from 1000 to 3500 rpm it stumbles. I checked the fuel pressure and it's running at 35 psi, which is almost ten under normal. Also the the spark plug wires are arcing to the head, but i've replaced all the wires, and i check them all the time to see if the headers have burned them. I've had the module on the coil checked, and it was fine. I checked around the coil and there's no evidence of it arcing. I also checked the fuel filter, and it checked out as well. Everything seems to be in order, but even after changing spark plugs and wires it still arcs. I've read alot about the optisparks going out, and the symptoms seem alot like what i've experienced, but i wanted to make absolutely sure before i go taking the water pump and all that crap off, but i would really appreciate some help with this.
.... and yes, lt1's came in 1994, they actually came out in 1993, at least to the f-bodies *camaro's and firebirds*[/QUOTE]
 

·
Registered
Joined
·
396 Posts
Not sure where you get your info but you obviously dont know much. LT-1 engine were around in 1994, not only in F bodies but in impala,caprice,buicks,caddy's and so forth. With that aside, the problems def. sound opti related. Pull the coil wire off the opti (behind the water pump) and look in there with a flashlight and see if you notice any moisture or any type of color or build up in there.

You are likely going to have to remove the opti and replace at the very minimum the cap and rotor, making sure when you take it apart to check the black module to make sure there is no oil or condensation in/on it. Contrary to popular belief, the opti is not a big deal to replace.
IDK man 94' w/LT1 , doesnt sound possible to me :eusa_think:
 

·
8th Gen Antagonist
Joined
·
13,660 Posts
Me thinks he was joking
 

·
Registered
Joined
·
7 Posts
You might want to check for a vacuum leak. Since it seems to smooth out at higher rpm's. I would think that if it was ignition related it would become worse and break up at the higher range.


Chris
 

·
Registered
Joined
·
741 Posts
yes i agree, vacuum leak.
Yes. After you check all the lines and everything looks good. No cracks or unplugged lines. Then I would look into the EGR as the culprit.
 

·
Registered
Joined
·
396 Posts
spray some maf cleaner around the intake manifold and if it revs up you got yourself a vacuum leak.
 
1 - 13 of 13 Posts
Top