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service engine light on after hard start

G

guessguy

Guest
I had a hard time starting my 96 CE yesterday. I had to turn it over 3 times before starting. Then after hearing a back-fire from the exhaust, the service engine light came on. The next day I had a hard time starting it again. The light is still on. What's the issue? O2 sensor?

thanks.
 
G

guessguy

Guest
Now my car is stalling while I'm driving. It hesitates, and I hear a backfire as well. Still have a though time starting and the engine light is still on. I hate to do it but I think I'll have to take it into a GM dealer and get them to fix it. I have a feeling it will be expensive.
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
May I make a wild-a__ed guess?

Opti-Spark.............strong hunch.
 
G

guessguy

Guest
I dont get it? Opti-spark? I have new plugs and wires in there. Could it be the distributer?


compyelc4 said:
May I make a wild-a__ed guess?

Opti-Spark.............strong hunch.
 
Joined
Jun 20, 2002
Messages
2,509
Location
Tallahassee, FL
Corvette
none right now :(
opti spark is basically the distributer for the LT1 and LT4 cars... it is a real pain in the A__ to replace because you have to take off the water pump and crank shaft pulley to get to it... they are notorious for failing, and the symptoms are as you described
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
Yep! The backfire is the dead give-a-way. That "probably" is your Opti-Crap "distributor" advising you that it is getting confused as to which plug to fire at which time. It is a stupid little cuss when its electronics get goofed up from water corrosion. Check our posts a few weeks back on Opti-spark problems. We wrote a book on that one!

Say....when's the last time you sprayed off your pride-and-joy engine to get it nice and clean?
 
G

guessguy

Guest
I've never washed the engine down. I just put in a re-built engine about 2000 miles ago. I think its still the original opti-spark on it though. Can I do this job myself? or is it too complicated?
 
Joined
Jun 20, 2002
Messages
2,509
Location
Tallahassee, FL
Corvette
none right now :(
If the engine was just rebuilt, it shouldn't be that bad... the water pump is pretty easy to get off.. the normal problem people have with the opti-crap is the crank shaft pulley, they tend to get rusted together and stuck, so you can't get the opti off... if yours was just rebuilt, it shouldn't be bad... basic tools, and competent mechanic skills is all it really takes
 
G

guessguy

Guest
Changed the Opti Spark

Well this past weekend, and my problem is now solved. It started on the first turn, and runs great. However, I have a question about the vacuum hose that is connected to it. When I removed the optispark the vacuum hose was not hooked up. When I connect it, my engine stalls after 5 minutes. Do I have the right hose? It leads into the driver side intake and I think it has something to do with the fuel pressuer. So right now I've left it unplugged.
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
I have not experienced those hoses specifically, but I believe one is a vacuum line which probably runs to that high-vacuum port you refer to. The other is an intake line. I'm not sure where it connects, but probably somewhere on the intake-side, upwind of the throttle-body. I believe the one connected to the high-side vacuum has a one-way diverter valve. If your engine is stalling, my guess is you have the hose routings reversed. Just a guess until I get up close and personal. I'll look at my setup tonight and let you know. Probably by then, though, some other guru on this site will have pegged your problem for you.

PS - That vacuum system helps remove moisture from the Opti internals, but for the life of me, I can not see how moisture can get inside of that sealed unit! I can see how the unsealed units sucked water however.
 

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