95 5.7 efi injector shutting off at 3k rpm with video

[nitrosteve]

Here is a video off an off idle pull and just at 3000 rpm it stalls and shuts the right injector off. I can then pull the throttle back to 1/4 and push the throttle back up to 3000 rpm and it will repeat itself. I have slowly accelerated ever so slightly and got it to go ahead and get past 3000 rpm and it will run perfect. The only thing consistent is it always happens at 3000 rpm. I'm thinking a bad injector or tps. What do you guys think?

 

[nitrosteve]

Video 2 same 3000 rpm shuts off then I return the throttle back to almost idle

 

[Bt Doctur]

whats the fuel rail pressure

 

[nitrosteve]

How would I go about testing that? The lines are hard would I have to cut one and insert a pressure gauge?

 

[bman440440]

one easy way to test the injector is flip the connections on the injectors to see if the problem follows the connection... if the same one shuts off its the injector

 

[nitrosteve]

Switched injectors wires and it followed the wires not the injector. Pulled tps sensor still did it.

 

[Bt Doctur]

Check the ground connections and check the plugs for the ecm. shutoff or remove battery cable first

 

[nitrosteve]

Checked all wiring and ground reconnected every plug on ecm checked no difference. Can I jumper both wires in the side that functions normally and attach it to the side that's malfunctioning?

 

[Bt Doctur]

Dont know never tried, give it as shot if you screw the wiring up the plug is the same as any gm car with TBI

 

[nitrosteve]

I soldered the good injector I think it was blue to the green so now both injectors are running of the blue side. Seems to have fixed the issue on the muffs. I did notice a hesitation at about 2800 rpm but when the motor got up to operating temps I didn't notice it. We are going for a lake test today. If all goes well I just saved 1200.00. What do you think the hesitatiin is? Seemed odd to me maybe the timing was not not advancing.

 

[nitrosteve]

It's running ok. Still hesitates alittle at 3k and lost about 800 rpm on the tach and about 9 mph. Maybe it is starving for fuel.

 

[Fun Times]

You may have lost an injector driver inside the ECM or the engine could be going into a power reduction mode shutting down one injector bank.
While this is a Volvo engine, pretty much the same concept as you both have MEFI ECM's. Limp Mode Causes

These two places "might" be able to test the ECM for you,
https://obd2allinone.com/mefiecms.asp
http://mefituning.com/

 

[nitrosteve]

Ummm well I figured out the problem. First I'm a tool. Second the lower unit gear oil res was low so it was putting it in limp mode. Seems like that would have been obvious but not for me. Boat ran great seems to be turning to many rpms now 5000 50 mph gps I have to back off the gas to keep it at 4600.

 

[Fun Times]

Sounds a whole lot cheaper than a new ECM.:thumb: Good to hear you were able to figure it out.:eagerness: