Volvo Penta 4.3 TBI
 

Thanks for letting me Join your group.

i am helping a friend with his early 4.3 (mid 90’s)
they lost the low pressure pump and had it replaced then it would not go over 2600 RPM. Watching the injectors when it got to about 2600 one injector dropped out, found this is called going into slow mode. I am a heavy equipment mechanic with some knowledge of automotive. I got a paper clip and my computer safe test light and checked for codes, only code 12 would flash. I am waiting on a high pressure pump it had a lot of debris in the screen. I am going down later ang going to test the harness to make sure there isn’t any opens or shorts in the coolant temp. Oil pressure and MAP circuits. Just reaching out to see if anyone has seen some known issues. I would give more engine info but the tags are unreadable.
Thanks for the help

Not sure if I’m posting this in the right spot🧐

Not normal for an injector to just shut off. What was the trouble that got you looking?

The engine will Rez to 2500 RPM and cutout out one injector ( Volvo calls this slow mode) basically limp home mode, then when throttle back to below 1200 RPM the injector will start again. It’s basically protecting the engine from high coolant temp, or low oil pressure but neither do these have occurred. Just hoping someone has ran into this and maybe has a good place to start.
We are very remote here with no Volvo Penta dealers

Thank you for replying.

NOTE: it only started after the pump was replaced, and shouldn’t have had any bearing on it.

Manual says to find out which is doing it is to; run motor with scanner attached and when alarm sounds then check scanner

Could also do it by when alarm sounds, disconnect each of the switches until alarm stops
ECT, oil pressure switch, Exhaust riser temp

I will check for exhaust temp. Sensors there is no shop with a scanner and the only way to get to a dealer is to drive through Canada but with Coronavirus that’s a no go.

Bring someone with
Drive until alarm turns ON, then start disconnecting switches (not sensors) until alarm stops

You don’t have to drive it. It will happen at the dock right after startup