DRM500RUBYZR-1

First- Buy a Factory Service Manual including the LT-5 supplement before you do ANYTHING,

Second- Look for something thta malfunctioned and is instructing the DIS to abort the start.

While it could very well be the DIS, it is safe to say that the ZR-1 community has observed very few DIS failures.

My 1970 Riviera wwas smart enough to not start if the oil pressure sending unit failed to indicate pressure while cranking. My point is a 1990's LT-5 likely looks for far more to be in order before it allows the start sequence to proceed.

Trying to diagonse this without the FSM is going about it the wrong way.

Before I would shell out what could be $1,000.00 or more if I could even find a DIS, I would want to affirm that it is the point of failure.
This of course is accomplished by following the troublehooting procedure for a no start in the FSM.

If my FSM was more handy I would check it for you, but I cannot believe that it would first branch to a faulty DIS. While it could, I just do not envision that it will. I am guessing the start procedure is looking for proceed signals from other systems and sensors, such as fuel, oil pressure etc. Your earlier mention of fuel pump replacement, or at least I seem to think you mentioned that raises some flags.

Get the FSM and let it guide you to the faulty component, even it turns out to be the DIS.

Best of luck, and keep us posted!

Marty
NCRSZR1
95PACER

DZielinski

Yes, both pumps were replaced, but I alrady checked for fuel to the rail on top of the engine. I have good fuel pressure.

Thanks.

Dominic Sorresso

I'm also suggesting that you look into whatever feeds a signal to the Ignition module for start-up.

DZielinski

I got it. I will start with my Electrical Manual and see what I can find and in the meantime look for a Service Manual. Thanks.

DRM500RUBYZR-1

DRM500RUBYZR-1

Dynomite

I guess I would try a good working ECM.....borrow one and put your chip in the one borrowed....plug it in and see if it starts (if it does not start, try a different chip). Who is to say a rebuilt/repaired ECM that had numerous bad solder connections is functional.

Very interesting thread and the functional connection between ECM and DIS is very informative
Keep us posted....and if you can find/borrow a functional DIS to try out would help. I am assuming the wire harnesses are not damaged/shorted in any way and no bent pins with all connectors continuous.

I am a guy who switches out components with good components to find which component is bad as you can tell. The rare difficulty of that diagnostic method occurs when two components have gone South at the same time

z06scentair

Updates?

DZielinski

Still looking to find a DIS module at a reasonable price. $995 is the cheapest I can find right now. I checked the 12v power supply to the DIS and grounds. They checked out OK. Still nothing from all the coils. Hoping to either borrow or find a DIS module through the winter so that I can have the car back on the road in the spring. I would prefer to not spend $995 just to see if the DIS is the problem.

z06scentair

That is most likely going to be the going price. I havent seen any forsale in quite some time.

If you buy it and it doesnt turn out to be the problem, you could resale and get your money back.

It's a solid investment.

corvettenorway

http://www.corvette-c4.eu/c4ersatzteile.htm ??? http://www.eurovettes.com/parts_specials.htm ????

Dominic Sorresso

Is that 450 Euro? That's cheap @ $1.25USD/Euro

corvettenorway

my brother got one from them for a 90 zr1

Dominic Sorresso

DZ,

Check out this diagnostic.

Tyler Townsley

There is a dis checker that I use to test the modules. The most difficult one to trace that I have run into was one that broke down when the crank speed got over 400 rpm. That is the point where the dis is controlling the spark and passes it off the ecm. It was ok below 400 but above that it began to break down. Acted like the wires were on the wrong cyl.

Tyler

corvettenorway

http://www.amazon.com/gp/offer-listi...on=refurbished

ghlkal

Refurbished for $995. What would "refurbished" mean in this case? Just cleaning it up? I imagine nothing is rebuilt/replaced, correct?

z06scentair

It looked like to me they are referencing the ecm being refurbished, however they do reference the part number. There is no refurbishing these module's, way to complicated.

Lots of custom manufactured componets inside these jewel's.

Dominic Sorresso

The ICM was epoxied. There is virtually no way to remove the epoxy without destroying the electronics.

Rkreigh

that would be quite a challenge!