2000 merc 200 EFI no start/no fuel pump

hi all, im working on a merc 200HP 2 stroke EFI motor with no start condition, (ot143331) it was put away wet last year and now would not start. the fuel pump was not running. testing with as probe i found power and no ground. during crank. when i sent negative to the (-) terminal the pump fired right up and ran fine. i shut it down multiple times and it is still working fine. the manual shows the pump gets its neg power from the EFI module.
any thoughts? i do not want to write this off as a fluke but the more i research , the less i find issue with.

pae0332 said:

hi all, im working on a merc 200HP 2 stroke EFI motor with no start condition, (ot143331) it was put away wet last year and now would not start. the fuel pump was not running. testing with as probe i found power and no ground. during crank. when i sent negative to the (-) terminal the pump fired right up and ran fine. i shut it down multiple times and it is still working fine. the manual shows the pump gets its neg power from the EFI module.

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The EFI module typically controls the fuel pump by switching ground.

Need to do some troubleshooting of the EFI module

thanks, i have a rinda scanner and these modules really do not have much in the way of scan tests and diagnostics. that plus th efact its now working properly, makes it even more difficult

ecu pump driver circuit is done... you can run it this way if ya want.. disconnect both pos and neg from pump and tape 'em up.. take a regular ground from anywhere on tha block to tha neg on tha pump.. find a "purple" anywhere on tha motor.. splice into it and go to tha positive on tha pump.. all purples are "key switched hot" which will turn ya pump on when ever ya turn on tha key.. you can run it this way for as long as ya want to.. know a few thats been that way for years.. some elect to install a relay to ease tha load on tha purple.. this will get ya on tha water till ya figure out which way ya wanna go............. there may be some one that can repair tha driver circuit in tha ecu.. jus don't know and/or trust most that say they can.............. jmo.

pae0332 said:

thanks, i have a rinda scanner and these modules really do not have much in the way of scan tests and diagnostics.

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If you have any electronics training at all, it’s easy enough to troubleshot a simple EFI with a voltmeter, a set of pin probes, a schematic and a pin out of the module in question.

JAN: your serial number is "zero" 0t143331... not an O... it won't show up anywhere with an "O"......

dingbat said:

If you have any electronics training at all, it’s easy enough to troubleshot a simple EFI with a voltmeter, a set of pin probes, a schematic and a pin out of the module in question

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its not that simple when the problem is intermittent. the ECU is enclosed and ive tested the hareness and the wiring is fine. as i originally stated, when i sent neg signal; to the pump,with the ECU still connected, the ecu "woke up" and has operated as it should each time since.

thats good... run it till it quits again and keep some black and purple wire handy.... or jus black maybe since tha red is constant...but tha only problem with that is tha red is constant power no mater if tha key is on or off.............