Cajun 2 Stepp

I'm with MER on this one.
Do the affected injectors have power to them?
One wire supplies power and the other supplies a ground through the ECM.
Unplug an injector and test for voltage with a test light with the ignition on and engine off.

Velocity Tom

There is no inj. pulse. I checked it with a noid light.. I quit to freekn hot.

Cajun 2 Stepp

Noid stays lit or not on at all?

Edit- I meant to ask if you had checked it with a test light and if the test light stayed on or not at all.
A noid light won't tell you if you have voltage if the ecm doesn't complete the circuit.

TooLateVTEC

iTrader: (1)

Start checking the injector harness for problems.

If that MEFI is like the other stuff, the ECM provides ground for the injectors.

BUP

iTrader: (9)

post your year and engine serial #. Trying to remember if Merc had a SB on this and or a ECM change for it. Something in the back of my mind recalls this but 100 % sure about the SB's. = Service Bulletins FYI.

Also is your engine(s) stock and is the ECM a OEM Merc stock tune - important as well.

SB

iTrader: (1)

I'm the real SB.

Just an FYI.
.
.
.

.
.
.
.
.
.
Sorry, just had to. LOL.

BUP

iTrader: (9)

that is funny, I hear you screamin. And that also can mean SON of B_ _ _ _ _.

tunertech

FWIW

unplug all injectors. test the resistance across each. They should read real close to 12 OHMs. if every thing checks ok, keep all injectors unplugged, use your noid light and and check for pulse. What a re your results. the common 12V + on the harness is black... go figure. The system is batch so you will see blue and green as well those are your grounding leads.

BUP

iTrader: (9)

He check with noid lites I thought already and nothing as in no power to the injectors - that's the way I took it but could be totally wrong. Just saying.

tunertech

it's ok, just trying to introduce a systematic approach to diagnostics.. you guy are on target, it's COOL