Injector Waveform

MotiCSC · Post by **MotiCSC** » Tue Mar 23, 2021 8:08 pm

Hello Guys,
Working on Toyota MR2 with P0300, on cold start CEL is flashing.
was managed to catch this injector pattern looking different then all the others.

As my experience is very little, and even though i know what a injector graph should look like, i would like to read your opinion.

I see voltage drop is "only" 12V, and pattern is not flat but curved.
After engine is hot, pattern goes OK. what would cause this? bad ECU driver?

muttnjeff · Post by **muttnjeff** » Thu Mar 25, 2021 10:42 pm

That looks like an ignition WF, did you mean injector or ignition?

Grant_Baker · Post by **Grant_Baker** » Fri Mar 26, 2021 1:11 am

It looks like you have one channel's power and ground leads connected across the injector power and ground terminals. Don't do that. It will damage your scope if it hasn't already.

Did you only have the one channel connected to the vehicle? Which scope model?

MotiCSC · Post by **MotiCSC** » Fri Mar 26, 2021 5:41 pm

Hi,
Thank you for your replies! i am a complete newbie into scopes.

it is an Injector from a Toyota MR2 2001 1ZZ petrol engine.

Scope model is 4425A, waveform taken with 10x attenuator, across voltage feed and injector ground from ECU.
any case for damaging scope this way?

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