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-   -   3VZE No Spark. Big Mystery (https://www.yotatech.com/forums/f116/3vze-no-spark-big-mystery-297963/)

Marque 12-02-2016 05:42 AM

3VZE No Spark. Big Mystery
 
First off, I just want to thank everyone on this site for their contributions. I recently pulled the old 3VZE out of my 94 pickup and swapped it with a newer one. Before taking that on, my mechanical experience was limited to changing my oil. With this site, a FSM, and a few youtube videos I managed to get it installed by myself. When I turned it over it started. and we ran it for a good min or so before turning it off because of a leaking hose. Before we started it back up again, my brother noticed that I had attached the ground wire from the battery to the engine block, which he did not think was right. He removed the ground from the block and attached it to the fender well. When I cranked it up again there was a pop and it would not start. Removed the wire from the ignition coil to the distributor and there is no spark being sent from the ignitor. I did some research and did all of the troubleshooting suggestions without any luck. Brought the truck to the local toyota guru and he said we had a bad ECU. Ordered another ECU and still no spark. Took it to another mechanic who found that the timing belt was off at least by 3 notches. Either I did not put it on right or the engine jumped time.

So my question is, would the timing belt being off prevent the ECU from sending a signal to the ignitor? It seems like it should still spark. He said he thinks getting the timing belt on properly will fix the problem but I don't know. I have no burnt fuses anywhere. I have tried just about everything you guys have suggested for diagnosing no spark and haven't found the problem yet. Any help is appreciated. Thanks in advance.

scope103 12-02-2016 06:09 AM

Are you sure there is a good ground TO the block? (This is primarily the cam bearing cap, passenger side at the back.)
https://cimg7.ibsrv.net/gimg/www.yot...f5555e9a59.png
You said "Removed the wire from the ignition coil to the distributor and there is no spark being sent from the ignitor [igniter]." The coil provides spark to the distributor, the coil is triggered by the igniter, the igniter gets the IGT signal from the ECU, which gets its timing signal from the distributor. The parts most likely to fail in that chain are the coil and the igniter. So you should test the coil http://web.archive.org/web/201212070...12onvehicl.pdf . Unfortunately, it is pretty difficult to test the igniter, but you can look for the IGT signal. https://www.yotatech.com/forums/f116...gniter-287857/

RJR 12-02-2016 07:01 AM

Some various thoughts:
- Re; the timing belt. Make sure you are looking at the relationship between the crank pulley and the cam pulleys, not at the marks on the timing belt itself. Those marks only line up once every half-dozen revolutions or more. They are there to help install the belt, but are not a reference for later timing checks, as they wander around as the engine continues to turn.
- Have you checked for diagnostic codes? If not, do so. There is something of a "handshake" between the ECU, distributor, and the igniter, and if that handshake fails you won't get a spark, but there should be a diagnostic code indicating the nature of the failure.
- If the timing belt is indeed off three notches, it will likely keep the engine from starting, but should not keep the ignition from generating a spark, since the ECU has no way of determining crank position independent of the distributor timing, so it can't know that the belt has slipped.
- Do make sure all of your grounds are attached as per Scope's diagram above.
- The "pop" concerns me. I suspect removing the ground from the block caused high current flow through something that wasn't designed for it. You may need to track this down before you achieve success.

Marque 12-02-2016 07:01 PM

Thanks guys. I will let you know how it goes. I will take a second look at everything again and try to wrap my head around it.


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