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Old 12-06-2009, 10:52 AM   #1
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Default No Injector Pulse...

I'm helping a mate install his MS that I built a while ago.

Unfortunately it's not injecting *any* fuel, it's a standalone with a full PnP harness etc. MS1 Using the MSPNP maps. The car is a 1.8 94

Which components on the board are used for driving the injectors?

I've scoped the signal lines and they just flatline when you're cranking the car, I've tried his ECU on my car and the same thing occurs. My ECU in his and fuel is injected/it attempts to start.

Scoping mine and you get a nice pulse as expected.

Everything else works etc i.e. RPM on TS/MT CLT/IAT TPS all read correctly.

Any ideas on what to test/might be faulty?
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Old 12-06-2009, 11:53 AM   #2
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http://www.megamanual.com/ms2/v3pcb_4.gif shows the injector output circuit. Have you checked the logs to see if it's trying to send fuel? Might want to scope the output pins on the MS.
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Old 12-06-2009, 01:01 PM   #3
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Already been through the MM with a fine tooth comb, and if you read my post you'll see I've scoped the signals...

Since realseid thought after comparing his ECU with mine that U4 is rather important and shouldn't really be missing....DOH!
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Old 12-06-2009, 01:42 PM   #4
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I didn't link you the manual, that's the injector schematic. I thought you were scoping the DB-37. If it's not showing up at the pin on the CPU, either the pin is dead or some sensor isn't working. That's why I said to look at the logs to make sure it was trying to output, then you can tell if the pin is dead with the scope.

And yes, U4 is necessary. If you look at the schematic I linked, it is the MOSFET for the injectors. Unless you are doing sequential injection or using some other driver, you need it.
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Old 12-06-2009, 02:27 PM   #5
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the MM.com link has all the scematics in it, trust me I went over all that stuff, I know how important U4 is was being sarcastic

Can't believe I missed it out in the build and then spent effectively 2 days trying to suss out what was wrong when it was something so bloody obvious, and to spot it literally an hour after originally posting is just sods law!

Cheers for the help tho!
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Old 12-06-2009, 06:05 PM   #6
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do you get a tach reading on your software?
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