93 LT1 Fast clicking SES and all digital guages gone crazy.

[green93]

Pardon my newbyness, but I have a problem that I have searched high and low for and have not come across any solutions to.

I can be driving down the highway around 65mph and the dash starts to click and flicker. The SES light starts clicking, or there is a clicking noise associated to the timing of the SES light going on and off. The entire digital dashboard goes nut. RPM guage shows between 0 and 5000 RPM erattically. The speedometer shows 4, 5, 6, 7. It just jumps around and goes crazy. It also backfires and runs like it is a 3 cylinder vehicle, :confused .

If I pull over and shut it off or let it die which it will do sometimes and start it again it starts fine and runs then after about 1 minute of getting back on the road it starts the routine all over again. Last time it happened I started it and it was doing this on startup, I turned the ignition off and pulled the key. Put the key back in and started it up until it would start and run as designed. Took around 15 minutes to get back to normal. As soon as I took off again it let me get about 1.5 miles and started again. Pulled over and performed the same process again. This time when I started driving the car ran like it was supposed to all the way home.

First off my optispark has decided to die after owning the vette for 7 weeks, which 4 of those weeks was at a repair shop attempting to diagnose the problem that turns out to be the optispark. After 1350.00 for a fuel pump replacement and still having the problem I decided to find out on my own. Got a code reader and seen that I was getting a 16 and 42. Found lots of posts on the opti. I am having the opti, water pump and a new delteq coil pack installed this weekend. But I am not sure this will relieve me of the problem described above.

Has anyone seen the flickering SES light before?

Randell (Green93)
1993 Corvette LT1
350ci 6sp DR450hp

 

[vette-dude]

Pardon my newbyness, but I have a problem that I have searched high and low for and have not come across any solutions to.

I can be driving down the highway around 65mph and the dash starts to click and flicker. The SES light starts clicking, or there is a clicking noise associated to the timing of the SES light going on and off. The entire digital dashboard goes nut. RPM guage shows between 0 and 5000 RPM erattically. The speedometer shows 4, 5, 6, 7. It just jumps around and goes crazy. It also backfires and runs like it is a 3 cylinder vehicle, :confused .

If I pull over and shut it off or let it die which it will do sometimes and start it again it starts fine and runs then after about 1 minute of getting back on the road it starts the routine all over again. Last time it happened I started it and it was doing this on startup, I turned the ignition off and pulled the key. Put the key back in and started it up until it would start and run as designed. Took around 15 minutes to get back to normal. As soon as I took off again it let me get about 1.5 miles and started again. Pulled over and performed the same process again. This time when I started driving the car ran like it was supposed to all the way home.

First off my optispark has decided to die after owning the vette for 7 weeks, which 4 of those weeks was at a repair shop attempting to diagnose the problem that turns out to be the optispark. After 1350.00 for a fuel pump replacement and still having the problem I decided to find out on my own. Got a code reader and seen that I was getting a 16 and 42. Found lots of posts on the opti. I am having the opti, water pump and a new delteq coil pack installed this weekend. But I am not sure this will relieve me of the problem described above.

Has anyone seen the flickering SES light before?

Randell (Green93)
1993 Corvette LT1
350ci 6sp DR450hp

Never had this happen to me in my 91 but it could be alot of different things happening. The opti-spark may be the cause (you've already said it was bad), the computer may also be going boinkers. A bad battery will cause weird things to happen too but you said it cranks okay so probably not the problem. I am sure others can shed more light on this at time goes on. Try to only fix one thing at a time and then test the car. Multiple fixes by guessing what might be wrong get real expensive.

Randy

 

[green93]

Thanks Randy for the post, will do the items listed first and go from there. But my concern was the computer. Not sure what this is a symptom of but will find out slowly but surely.

Randell (Green93)
1993 Corvette LT1 soft/hard
350ci 6sp DR450hp

 

[jwilliams]

vette-dude your 91 should have an L98, totally different motor than what he's got. Thankfully an L98 doesn't have an opti spark.

Green 93 I wish you the best of luck. Purely guessing it sounds like you may have a ground issue somewhere in the vehicle. Intermittent electrical issues are not fun for you or any tech working on it

 

[vette-dude]

vette-dude your 91 should have an L98, totally different motor than what he's got. Thankfully an L98 doesn't have an opti spark.

Green 93 I wish you the best of luck. Purely guessing it sounds like you may have a ground issue somewhere in the vehicle. Intermittent electrical issues are not fun for you or any tech working on it

I know that (he said with a smile on his face ). I also had a 94 before this one. That's why I got rid of the 94--no more optijunk issues (and the 91 is a Vert.) Just trying to help the guy out and give him some other things to look at if the optijunk fix doesn't solve the problem.

Randy

 

[rrhayden]

I had a similar issure with my 92. One day driving I heard a clicking and everything was going nuts. The issure was a bad connection to the ground terminal on the battery. So you might want to check grounds.

Good luck

 

[green93]

If it is that simple I will kick myself. Will check that tonight before it goes to get optijunk replaced. Thanks for the heads up.

Randell (Green93)
1993 Corvette LT1 soft/hard
350ci 6sp DR450hp

 

[BlackNBlue95]

I had a similar issure with my 92. One day driving I heard a clicking and everything was going nuts. The issure was a bad connection to the ground terminal on the battery. So you might want to check grounds.

Good luck

Very common to have corrosion issues with the side terminal setup.
-=Rick

 

[green93]

I have not driven it enough to determine if the new opti has cured this but here is an update as to what I have done and what it is doing now.

Well I put the new optispark on and the new Delteq coil pack. It is not doing what it was doing before where it would just die at 75mph. Now it will only run correctly between 2500 and 3500 rpm. Mechanic is now telling me that an exhaust leak on the manifold is causing too much oxygen to make to the car run like this. Will update more as I replace more parts, getting very expensive.

Randell (Green93)
1993 Corvette LT1 soft/hard
350ci 6sp DR450hp

 

[sothpaw]

Pardon my newbyness,
I can be driving down the highway around 65mph and the dash starts to click and flicker. The SES light starts clicking, or there is a clicking noise associated to the timing of the SES light going on and off. The entire digital dashboard goes nut. RPM guage shows between 0 and 5000 RPM erattically. The speedometer shows 4, 5, 6, 7. It just jumps around and goes crazy. It also backfires and runs like it is a 3 cylinder vehicle, :confused .


Randell (Green93)
1993 Corvette LT1
350ci 6sp DR450hp

I did experience the SES light, guages gone nuts this weekend. That's because I was playing with my ECM and I didn't put the chip in tight enough. My cluster was constant at 0 mph. Car also ran poor if you gave it gas.

The opti. will not cause the cluster to go crazy unless the engine is also going crazy. Was the engine rpm up at 5000? or did it just say that? If it just said that then you need to look for an electrical problem.

 

[green93]

Southpaw,

I had exactly what you are referring to in the cluster, but I was moving and attempting to accelerate at the time, so the RPM was actually showing 0 - 5000 but it was jumping and definitely accurate.

Were you driving or sitting when your speedometer showed 0. The reason I ask is because if I was pulled off on the side of the road the speedometer would sometimes show a large negative number as well when doing this.

Randell (Green93)
1993 Corvette LT1 soft/hard
350ci 6sp DR450hp

 

[sothpaw]

Southpaw,

I had exactly what you are referring to in the cluster, but I was moving and attempting to accelerate at the time, so the RPM was actually showing 0 - 5000 but it was jumping and definitely accurate.

Were you driving or sitting when your speedometer showed 0. The reason I ask is because if I was pulled off on the side of the road the speedometer would sometimes show a large negative number as well when doing this.

Randell (Green93)
1993 Corvette LT1 soft/hard
350ci 6sp DR450hp

No, I was moving when it said 0 mph. There was a CCM code 41 (I think) in there, along with the SES flashing. 41 was for loss of ECM serial communication. Basically, car was brain dead. Hence no speed, and I got that trip around the block in for zero miles.

Again, listen to the engine with your hear. If it's really going at 5000 rpm it will be loud! Even instantaneously. You really should pull the codes too and and tell us what you have in the CCM and ECM. It's easy, you just need a paper clip + directions. (I don't use a paper clip though--I got the plastic covered paper clip + manual for Gordon Kilbrew)

 

[sothpaw]

Pardon my newbyness, but I have a problem that I have searched high and low for and have not come across any solutions to.

I can be driving down the highway around 65mph and the dash starts to click and flicker. The SES light starts clicking, or there is a clicking noise associated to the timing of the SES light going on and off. The entire digital dashboard goes nut. RPM guage shows between 0 and 5000 RPM erattically. The speedometer shows 4, 5, 6, 7. It just jumps around and goes crazy. It also backfires and runs like it is a 3 cylinder vehicle, :confused .


Has anyone seen the flickering SES light before?

Randell (Green93)
1993 Corvette LT1
350ci 6sp DR450hp

The more I re-read this, the more I would look at an electrical problem here. But it should be easy to diagnose if this is the opti. I would bet heavily on electrical, not opti, though. When my new replacement opti went, the engine would just run poorly. It didn't throw SES or any codes at all.

 

[Jeb]

$1350.00 for a fuel pump replacement?

Is the '93 that much different than my '87?

 

[green93]

Well for an update and my apologies for not updating when posts were made. Here is the status. The opti and Delteq did nothing in the way it was running with the exception of it only running correctly between 2500 and 3500 rpm.

The mechanics I have it at now. "Lakeside Motosports - Winner Tire" have diagnosed it as the brain/computer on the car. They unmounted it and when they tapped on the corner of the computer the car would do the exact same thing, the ses light would flash like it was connected to a quick change relay and the dash would go crazy just like described above. I had the car in there to get new exhaust manifold gaskets because of the leaks the other mechanic told me that the opti and delteq could run like it was with exhaust leaks because the o2 sensors were going nuts, B***S***.

Anyway they are putting a new box on it and we will see. A new one is only 175.00 from the dealer.

As far as the fuel pump goes, we have accosted the mechanic and basically told him how wrong that was and that when our friends asked about a good mechanic we would tell them who not to go to. He is reviewing all of our bills in regards to refunds.

The fuel pump is not that much different than on your 87, the mechanic was trying to be my friend and not even kiss on the back of the neck as I was leaving.

But it is all starting to come together and hopefully after all this I can get some driving pleasure from it with photos to post soon as well.

Randell (Green93)
1993 Corvette LT1
350ci 6sp DR450hp

 

[green93]

Well time for another update on the Green93.

Well after putting the new optispark, waterpump and the delteq coil pack on here is where it stands. Everyone told me that with an exhaust leak at the exhaust manifold that it could cause the os2 sensor to dump more fuel into the system. So I got that fixed same results would not run right except between 2500 and 3500 rpm.

Decided to pull the delteg and use OEM coil and optispark. Car started and seemed to be running right. That was until I put a few miles on it. The car is still running very lean with no codes. The rpm at idle never gets below 1500. The heat from the engine on a 95 degree Chicago day is excruciating, even with the top down, or especially with the top down.

Have to trace down why the car is overheating, weather it is due to running lean or if there are other troubles.

Back to the delteq. Called them and they stated that they are aware of the problem I am having with the 92 - 94 LT1 corvettes. They have sent me another ecm module to resolve the issue. I will put the delteq back on after I get the car running the way it is supposed to with the OEM optispark and coil.

Now back to the running hot issue.
Has anyone seen this before on the 93, where it will not idle down and runs between 230 in town and 193 on the highway. Could it be one of my cooling fans has given out?

Randell (Green93)
1993 Corvette LT1
350ci 6sp DR450hp