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Gregd

'92 LS1 timing jumping

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Hi there, I'm trying to get the timing right on this engine. The engine is from a '92 Corvette, ( now with a 55 Chev body on top.) It has a dissy with a high and low resolution outputs from it. Single coil and grouped injectors.

Any ideas on the correct settings for this engine?

Have tried Falling and Rising edge settings.  And the different the different tooth settings. Still jumping all over the place.

Looking for help on this matter to get it sorted.

Thanks, Greg.

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Hi Greg,

An LS1 with a distributor is a new one on me...  If you have one of our ECU's with a built-in triggerscope can you please do a triggerscope and attach it here.  Here is a quick video how to do that:  https://1drv.ms/v/s!AiYbYlZQuRHPmieMTkwQDCXEb2LY

If you have one of our ECU's that dont have a scope (Atom or Monsoon), then a good place to start would be to give us a couple of photos of the inside of the distributor so we can see the sensors/toothed wheels.

 

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I just googled Optispark, I had never heard of it.

I expect it would work if you choose Nissan 360 Opto trigger mode and then run the "Test ECCS Sync" test.

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19 hours ago, Brad Burnett said:

There is a ton of information right at everyones finger tips...….

From the help file

LOL, so it is.  At least my guess was right...

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The owner of the car is positive that he brought a corvette with a LS1 in it from the states as a doner car. Just did some research on the vin number. And it's looking like a LT1. He wanted a 300 plus hp motor but looks like he got the basic 300 when it was new. Will swap the ecu to the LT1 settings and see what happens. I'm stii learning about these wonderful engines.

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Still having trouble getting this beast going. Found gummed up injectors, fouled spark plugs, poor connections to the injectors and last but not least a leaking water pump which is dropping onto the Optispark unit.

Does anyone have a trigger pattern I could compare what I have verse what is a running engine.

Tried to take a trigger scope capture have failed. Will try again.

 

Trigger Scope Log 2018-07-29 12;48;19 pm.llg

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9 minutes ago, Gregd said:

I took a scope shot of the triggers and, am wondering if it is producing a faulty pattern? Thinking it is.... 

No, that scope actually looks about right.  Did you run the widest slot test?  Do you get RPM displayed when cranking?

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I would say that is working ok in that case.  How many degrees it is showing in the widest slot setting?  Do you have a spark now?  Have you put a timing light on it and set base timing?

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Widest slot setting comes up with 22 degrees,  Spark and injectors. If you run the injector test for inj1 -2 you can get it to fire and try to run for a few seconds then nothing,,, fuel pressure good. Have marked the crankshaft pulley and  checked timing, near 10 degrees. 

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Sounds like maybe lack of fuel then.  If you are using traditional mode try increasing the master fuel by say 50%.  If you are using modelled mode a simple method to increase fuel is to increase the engine capacity setting.  Or another quick test to confirm it is a lack of fuel is to add an alternative fuel source like a spray of ether or a squirt of petrol into the manifold.

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Adam, you are a legend. Sometimes you can't see the wood for the trees.  Awesome advice. The engine now runs after the 50% increase. Now a slight timing change and it will be purring even more. Thanks heaps.  Greg. 

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Had this engine running for a little bit now. Running extremely rich. Tried cutting back the injectors and master fuel. Cutting back master fuel makes it run rough and idle fast. Injectors not making much difference. Is there something else I am missing? 

Had injectors serviced and refitted. Noticed right bank O2 not working correctly (after nine years of sitting around). Mechanic was going to replace. 

Aftermarket fuel pump fitted and using OEM regulator.

Greg.

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Adam. The injectors are wired as per factory in two banks of 4. 1357 and 2468. Could easily change to individual feeds. O2 sensors are single wire OEM 92 corvette fitted to new pipes. Injectors are either 14 or 17 ohm  OEM LT1 factory fitted. Serviced and reinstalled. I would have to recheck.

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