LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Opti or something else?

Thread Tools
 
Search this Thread
 
Old 06-19-2012, 01:48 PM
  #1  
Staging Lane
Thread Starter
 
Jet49's Avatar
 
Join Date: Aug 2008
Location: St. Louis, MO
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default Opti or something else?

I have a all stock 93 A4 Trans Am, 103k.

On the way back from the gym, I started to feel like a stutter with the pedal and for a split second I could move the pedal freely before the car starts to go again.

After driving a bit more, I noticed that anything above 1500-1700 rpm like when I hit the gas a bit , it will fall on its *** for a second and I can hear a single knock-like noise from the engine bay before it accelerates again.


Tried playing with the pedal in park and it does the same thing when tapping the gas it will stutter, and I hear a pop noise out of the exhaust but not every time it does it.

Is this a sign of the opti going out or something else?

It has NGK55 plugs in the past 25k, a new waterpump, and wires.

Edit: Also forgot to add, I filled up yesterday, but would bad gas cause this? It isn't knocking/ pinging though.

Last edited by Jet49; 06-19-2012 at 02:37 PM. Reason: Edit
Old 06-19-2012, 02:30 PM
  #2  
TECH Regular
 
Jr.Samples's Avatar
 
Join Date: Oct 2011
Location: Keller Tx
Posts: 407
Likes: 0
Received 2 Likes on 2 Posts
Default

Check the wires first. Make sure they are on snug.

I was on the way back from an all you can eat buffet when mine went south.

Changed
opti
plugs
wires
o2's
coil
ICM
coolant temp sensor

Turned out to be a fuel pump going out. Weird huh?
Old 06-19-2012, 03:16 PM
  #3  
11 Second Club
iTrader: (1)
 
96capricemgr's Avatar
 
Join Date: Sep 2004
Posts: 11,975
Likes: 0
Received 12 Likes on 12 Posts

Default

25K miles on a basic copper plug with a wide .050 stock gap to start would likely cause ignition issues.
You can't expect 100K out of plugs unless you go platinum or iridium.

People are way too quick to jump on the anti-opti bandwagon. If you assemble things correctly and don't neglect it it works just fine. They are a distributor though and as such cap and rotor should be considered tuneup items as plugs are and a regular TR55 plug I would not expect to last 25K miles.
Old 06-19-2012, 03:34 PM
  #4  
TECH Addict
iTrader: (1)
 
ahritchie's Avatar
 
Join Date: May 2010
Location: Charlotte NC
Posts: 2,243
Likes: 0
Received 1 Like on 1 Post

Default

Did it start happening suddenly or gradually over time?

My vote is ICM

then wires, plugs, opti, coil
Old 06-19-2012, 05:08 PM
  #5  
Staging Lane
Thread Starter
 
Jet49's Avatar
 
Join Date: Aug 2008
Location: St. Louis, MO
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for all the advice. I'll have to check all the plugs and wires tomorrow.

It just happened suddenly , it was running perfect before that. (daily driver)

I hope its not the plugs going bad, didn't know they would be only good for 25k considering they were like 50 bucks if I remember correctly lol.

If it were the opti or icm , how big of a pita would it be? And I guess how much would it be for each part ?
Old 06-30-2012, 08:38 PM
  #6  
Staging Lane
Thread Starter
 
Jet49's Avatar
 
Join Date: Aug 2008
Location: St. Louis, MO
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default

Update: About two days after the last post, it ended up doing it again and went down to 300 rpms suddenly nearing at a stop sign right before I entered my neighborhood -_- . Ended up having to get it towed to a neighbor's shop.

Ended up being the opti. The old one had the wire/sensor burnt through along with the plastic seal being open slightly. Oh, and it had oil on it from my intake leaking.

Runs much better now that its fixed.

I guess the StL 105+ degree heat maybe messed with it a bit too




All times are GMT -5. The time now is 02:05 PM.