Help?
Thread Starter
Advanced
Joined: Jan 2006
Posts: 59
Likes: 0
From: Anoka MN
Help?
I have a 94 C4. It runs great, and when you push it hard it flys great. But, when you "kinda" get on it and reach about 3700-4000RPM the car seems to shut off for a sec. The tach drops towards the zero, then the car relights and runs fine. Except the service engine light comes on(but resets if you disconnect the battery). It has done this 4-5 times this past week. I just drove it 800 miles round trip in the past 3 days and it ran super. 70-75 MPH w/AC and 26.8 MPG. Any ideas?
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Sorry.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 207
From: Orlando FL
Welcome to opti world. Not many opts actually fail with this code because that part of the opti is prety reliable. I would double check the connections at the opti and PCM. Re-seat the connectors, clean them, go thru the steps.By memory, the 'black' connector (which are the 'B' pins) is the one you want on the PCM. Good luck.
Thread Starter
Advanced
Joined: Jan 2006
Posts: 59
Likes: 0
From: Anoka MN
Optispark
I haven't cleaned the connections yet, but I will try that soon. I have also read not wash a LT1 cuz the Optispark could start mess'in with me. Well, when I got the car I washed the motor(damm) before reading not to. If it is cuz the optispark getting wet is the cause here, would a cap and rotor replacment be a good idea, or is replacing the whole thing a must? Need to keep this low cost.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 207
From: Orlando FL
The cap is like a regulator distributor cap, it will not throw a code. That is where the high voltage is. The other section is the part that sends the timing resolution pulses to the PCM and thats the piece that you are having the problem with. In that case, if this is all true, changing the cap will do nothing for you, the whole body needs to be changed. Besides a 12 year old opti is to old to change the cap with all that work. Having said that, a GM replacement can be had on Ebay for about $300. There are some other sources and upgraded optis for $600 +. If you can do the work your self, this could work for you. Otherwise pay a good shop and bite the bullet.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
To keep it "low cost", you're going to have to spend a little money to save a lot. Try all the simple, easy things. And do a search here in tech section for optispark diagnosis, fixes. Keep thinking simple and easy, it might work.
Then, get either the FSM (Factory Service Manuals by Helm, Inc. for about 80-100) or look for a Haynes Manual--not as complete, but adequate. Then, you may (MAY) have to change the Optispark yourself. This will save you somewhere in the area of 3-4 hours of labor charges at whatever is your area's going rate (hmm, mpls. 'burb? 75/hr.? you betcha.).
Good luck.
Then, get either the FSM (Factory Service Manuals by Helm, Inc. for about 80-100) or look for a Haynes Manual--not as complete, but adequate. Then, you may (MAY) have to change the Optispark yourself. This will save you somewhere in the area of 3-4 hours of labor charges at whatever is your area's going rate (hmm, mpls. 'burb? 75/hr.? you betcha.).
Good luck.
Last edited by AORoads; Jun 6, 2006 at 06:38 PM.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
370.78 10457702 distributor
5.16 10217886 seal
49.47 10219554 water drive shaft
2.73 10128317 opti seal
.39 ea 10128343 water pump gaskets
plus labor.
Buy the Helm Factory Service Manual if you plan to do any work yourself, worth their weight in gold.
Yep that is an opti issue.
How long after washing the engine before this started happening and how much time has elapsed since?
5.16 10217886 seal
49.47 10219554 water drive shaft
2.73 10128317 opti seal
.39 ea 10128343 water pump gaskets
plus labor.
Buy the Helm Factory Service Manual if you plan to do any work yourself, worth their weight in gold.
Yep that is an opti issue.
How long after washing the engine before this started happening and how much time has elapsed since?
