Ultimate Technical Challenge

[florida95vette]

Heres a good treat for you technical Corvette Owners.

I just bought my first 1995 Lt1 Vette. Low miles: 42000 miles, automatic
I have be recently a victum of a gremlin, I think.
Car was running fine then shut down. Would restart, but after waiting a few minutes. Also, now door lock on driveside moves on it's own, interior lights flash, and security light on dash will be normal and flash, other time not present at all. ( VATS issue? ) But before answering let me finish. I can start the car up and it will run fins, but soon after ( about 5 minutes ) will bog and cough and shut down the engine. Wait a few minutes, restart, and do it again. Since I bought the Vette, it has ran great for 300 miles, but now throwing many codes. (I bought a scanner to pull these)

Code 33 : Map Sensor Signal Voltage too high
Code 16 : Ignition System Problem - Loss of Lower Res Pulse Signal
Code 36 : Ignition System Problem - Loss of high res pulse signal
Code 42 : Ignition System Problem - Electrical Spark Timing ( EST ) is grounded
Code 83 : Torque Converter Clutch Solenoid Circuit Problem
Code 90 : TCC Brake switch malfuction

Please let me know what your techy covette owners this the problem may be.

 

[nyernga]

My initial thought is a possible catalytic converter problem seeing as it runs fine then bogs down. Let's see what everyone else can come up with. It's obvioulsy something that works fine cold then acts up after getting hot.


Len

 

[FX3FX3]

I had a Z28 with that problem and I took it to the freeway and did a top RPM shift to all gears, "the cold" went away, try, it may work for you.


Good Luck

 

[florida95vette]

Update

After a few hours of cleaning and check majority of wire connection, a reset the codes and now have ended up with Codes 42 and 36

New thoughts?
Opti - Spark
Vats
Electric Spark Timing ( EST ) - haven't checked, don't know where it is.

 

[Ken]

I'd still check the cats.

 

[florida95vette]

Another Update

I checked fuel pressures during the complete cycle of running the dying.
Prior to start: 42 lbs
Start : 38 lbs
Start of hesitation : 38 lbs
After car dies: 42 lbs

So I'm going to assume fule is not the issue.

I also noted the coolant temp at time of shut down, which was found to be at 180 degrees. I feel this might be when the car changes from open loop to closed loop. If so, what would be affected?

As for the cats.....how do you check them?

 

[jmccloud]

Gremlins

I bought a '95 about 2 1/2 years ago and experienced similar (but not as severe) symptoms. Flashing 'Sys' light during accel, dead battery when the door was open for 1/2 hour, didn't always start on the first try, sick horn.
Bought tires 6 months or so after getting the car and decided to buy a battery while the car was there. The old battery was likely the original (1995 removed in 2002 so it was due).
All the gremlins went away. The shop did clean up both ends of the battery leads. The ground lead was in the worst condition at the 'frame' end (not the battery end).

 

[limomanb]

Try replacing the MAF relays...that was the cure for mine as well. I also thought it was the cats.

 

[Tim Scales]

Could very well be the Ghost of all Ghosts...the dreaded Opti. The Opti will make it do many wierd things and leed you to think it is everything else. Check it very closely. With 42,000 miles if it hasn't been replaced it is about time. Especially if it is a florida car...underhood temps is a major factor in the life of the Opti spark unit. A hard job to replace but can be done easilly if you follow the following...1. Drain radiator. 2 remove air cleaner duct to throttle body. Remove all the wiring (At Connectors) from water pump housing and the throttle body (only the ones that are in your way). 3 remove water pump. 4 remove the harmonic balancer pulley. (Sometimes will take soaking over night with liquid wrench and 2 people one below and one above using steel bar and hammer to beat/force pulley off. Then lastly, remove plug wires and Opti unit. Be sure to make wires and what location they came from. Personally I would replace the wires and Spark plugs while I was doing this as well as the serpentine drive belt. Be careful when replacing plugs on drivers side. you will have to loosen and move the ASR unit. Be sure you don't "jerk" any of the cables out of place ...if you do you'll have to re-adjust the cables. not hard but a timely thing to do as it id trial and error type thing.
I hope that the OPTI is NOT the problem but if everything else has been tried that is where I would look. Good Luck! tim