200 EFI injector problem

[shipwright]

OK here goes, I have a 200 Merc EFI. Runs like &*%$#! Got nice hot spark on all six, good grounds everywhere. Checked at night and no spark leak. Took off manifold cover and had a friend turn key over so I could check injectors. Found that top 2 were not firing. When I had motor running and pulled each plug wire, only one cyl seemed to lose RPM. Does this seem right? I know its not direct injection so I'm thinking its just not getting enough fuel. I'm gonna test injector leads to make sure they are getting a pulse. If I get pulse then I'm going to clean injectors and retest. Am I on right track?

 

[Don S]

Re: 200 EFI injector problem

Clean out the VST and make sure the screens on the pump inlets are clear. Completely flush the system, new fuel filters, make sure there is no water in the tank of the fuel lines to the motor. Yes, send the injectors out to an injector cleaning company. They can bring them back to new condition. But if you put them back into your motor with a dirty fuel system, they clog right back up and you get to do it again.

 

[shipwright]

Re: 200 EFI injector problem

Update: unplugged ALL sensors and modules, runs great at top end. Idles like crap though. Fuel pressure is good. Compression is good. It seems like either the detonation sensor and/ or module is bad or the temp sender bad. Temp sender goes straight to ECU. I connected a bias jumper between switchboxes when I disconnected the detonation module. Not sure if temp sender needs detonation control system working or not. Ditched spark advance module too. Runs super rich at low rpm. gonna time it tomorrow see what shakes out. Hope not a ROD Cap! lol