Chevy Impala SS Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
Hey Y'all. I am new to the forum but have owned a 1996 FWB with the LT1 many years ago. I just got my hands on this 1995 Impala SS. The previous owner was having an issue where it would "misfire" randomly to almost stalling out. I couldn't replicate it when i test drove it for almost 20 mins but based off his description of the issue and the fact it ran pretty solid, I knew this was one of a few possible issues. Literally 1 minute after handing him the cash and taking the title, it happened. The sputuring, hesitiation all pointed to a vacuum leak but i was able to drive it 20 miles back homes with a straight highway run. Found the 2 evap vacuum lines completely dried out and crack. I fabricated some hoses to replace it. Was happy to have that sorted out. After days, I noticed a ticking sound coming from the rear of the driver's side exhaust manifold. One bolt was loose and the other was broken off. So I did the smart thing and ordered some BBK headers.

Current situation: The water pump, coolant temp sensor, hoses, radiator all are new but I see a good amount of oil leaked all down the front where the opti is. I will assume the cam and opti seals need to be replaced. This is now my new daily driver so I had to drive it to work and noticed sometimes it would take a few seconds to start right up. It would however start. I felt a loss of power, and a miss but was waiting to get to the weekend to change out the headers, plugs and wires. Anyway, I go to start it at 5 am for work and it would crank, sputter and die instaly. Tried several times and no luck. Had it towed to my mechanic show (family member). Finally got to put it up on the lift and we see the oil and grime around the opti. Funny thing is, it started right up once it got to the shop. What do y'all think this could be? I was thinking opti, ICM, Coil. I ordered basically everything for a tune up including a new OPTI just to be sure and not have to deal with it again.

I will keep everyone updated on the process. I want to turn this into a solid daily that performs.

View the quick video here: Impala SS
 

Attachments

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
After I swap out the headers, plugs, wires, fuel filter, I'm going to take a look at that. Maybe that can reveal some issue. Also the complete front end is getting replaced. had a real bad swaying issue and notices everal bushings we worn. I ordered Energy Suspension Poly bushings for the whole front. Ill tackle the rear after recouping from this hit to the wallet. 😅
 

·
Registered
Joined
·
545 Posts
Congratulations!
One thing that's changed in recent years--the only Optis are aftermarket, and there are many threads/complaints about poor/inconsistent quality--crappy materials, crappy assembly methods, crappy sensors that fail or are dead out of the box, even wrong machining on the shaft so built-in wrong timing. Point being--don't toss your old Opti, esp because the Mitsubishi sensor in it seems very highly regarded compared to what's available now. If the bearing's decent, you'll be much better off rebuilding the old Opti with a good quality cap/rotor. That'll also let you torque/loctite the inner screws properly and seal the unit better, none of which you can trust with the new units.
 

·
Registered
Joined
·
3,085 Posts
You have what sounds like the typical old ICM overheating and you get the starting and stalling symptoms you talked about.
I would replace ICM, and test. If it still does it, rebuild the opti you have with parts from one you bought. There is a whole thread on how to do it properly.

Good Luck.
-ALF out....
 

·
Registered
Joined
·
2,787 Posts
... I go to start it at 5 am for work and it would crank, sputter and die instantly. Tried several times and no luck.
Had it towed to my mechanic show (family member).
Finally got to put it up on the lift and we see the oil and grime around the opti.
Funny thing is, it started right up once it got to the shop.
What do y'all think this could be? I was thinking opti, ICM, Coil.
I ordered basically everything for a tune up including a new OPTI just to be sure and not have to deal with it again.
Did you order a new Opti- Vent & Vacuum Harness?
When the diagnosis points to an Opti-, the Vent & Vacuum Harness is far too often overlooked.
Coil, coil driver module, plug wires, even the Opti- electrical harness that runs over the top of the engine, are all cheaper and easier to R & R than the Opti- itself.
 
  • Like
Reactions: MWP

·
Super Moderator
Joined
·
9,446 Posts
Ignition or fuel. Buy a fuel pressure gauge and keep it with you at all times. Ignition system - coil, ICM, plug wire, check for corrosion. Make sure the four ground wires at the coil stud are in good condition.
 
1 - 9 of 9 Posts
Top