Chevy help

[HoPpeR]

Ok I got 94 lt1 installed in a wrangler.  I am not getting any spark.  Replaced the optispark, coil and had the module tested and it was good.  VATS system was programmed out.  Checked all plugs to sensor and everything seemed good.  Any ideas?  Thanks HoPpeR

[old school truck dude]

http://delteq.com/products_opti.htm

By the way this reads, Id be lookin at whatever it uses for a crank sensor

[MR NASTY]

Did whatever it came outa have one of those anti theft deals in it?  Might be something to check into.

[MR NASTY]

I missed it in the first post but I'd still bet there's where your issue is.

[old school truck dude]

Will that VAT system allow it to crank over but not start?

[HoPpeR]

I think the VATS will let the motor start for a few seconds and then shut it off but it won't start at all, no spark

[old school truck dude]

Thinkin crank sensor - is there a way to read codes on it?

[HoPpeR]

There is no crank sensor it is part of the optispark system.

[old school truck dude]

The term "Opti-Spark" describes the two functions of this distributor: optical ("Opti") engine speed and position sensing, and high voltage ignition distribution to the eight spark plugs ("Spark"). To perform these tasks, the Opti-Spark distributor contains a high-resolution engine speed encoder, a low-resolution engine position encoder, and a standard distributor cap and rotor assembly.

The high-resolution encoding is done with a 360-tooth trigger wheel spinning at camshaft speed. THAT THING RIGHT THERE IS WHAT I THINK WE ARE LOOKIN FOR.>>>An optical sensor reads these spinning teeth, and creates a simple 0 or 5 volt signal, depending on whether an opening in the teeth is or is not present. As the trigger wheel spins with the engine, this 0 or 5 volt signal becomes a square-shaped voltage signal, or "square wave" in technical terms. This signal is then sent to the engine management computer to determine engine speed.


Theres something either in the dist or on the front of the motor that determines the position of everything, it runs off the cam, depends on what year it is

[old school truck dude]

First and foremost, there are the typical wear, heat, and moisture problems associated with a distributor cap and rotor. Since most Chevrolet V8 engines feature an easily accessible rear-mounted distributor, it is not a big deal to change the cap and rotor every 50,000 miles (or sooner in high performance applications). Plus, the availability of standard-style cap and rotor assemblies makes them extremely cheap. These facts do NOT hold true for engines with the Opti-Spark distributor.

From an accessibility standpoint, both the water pump and the crank pulley need to be removed in order to gain access to a failed Opti-Spark distributor. On Camaros and Firebirds in particular, this is not a quick (or fun) job.

From a reliability standpoint, the environment at the front of the engine is notoriously harsh for things like heat, water, and debris (not to mention other variables like leaky front crank seals and worn, leaking water pumps!), but the Opti-Spark distributor is not even sealed on 1992-1994 models! Later versions of the Opti-Spark incorporate a seal and venting provision, but are by no means free of problems.

From a cost standpoint, the Opti-Spark units can retail for well over $400, depending on model year. Dealers have been heard to quote over $1000 (parts and labor) to replace this item!

To add insult to injury, the Opti-Spark distributor uses a "Correct-a-Cap" design that places the spark plug wire terminals on the proper side of the engine for easy spark plug wire routing. To do this, the terminal traces molded into the distributor cap must come extremely close to one another, which leads to premature arc-over in high-load applications and applications using constant high-voltage (Capacitive Discharge) ignitions. Not good.



Sounds like this system is not a good one to have for off-road, expensive parts and hard to fix

[HoPpeR]

Yup already changed it all. Still nothing.  MAtter of fact I changed it twice.  Still nothing.  I know theres got to be something I am over looking, I just got to find it. Thanks

[Disturban]

You are correct, VATS will allow it to start for a few seconds before it cuts fuel and ignition. Are you getting spark at all? Are you getting fuel?

[old school truck dude]

Again, is there a way to read codes on this set-up? Also, it must be losing the electric at some point, need to find where the break in the connection is, something is not allowing it through. Got electric to the system?

[HoPpeR]

I figured it out today  ,  I had the wrong iginition wire running to the relays for the computer.  When it was in run mode I had the right juice but when it turn to start mode it would kill all the power.  Got it wired correct now and sounds real good.  Thanks for the help, HoPpeR     

[MR NASTY]

Sweet