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5.7 GSI Injector Problem

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Samuel JR

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Hello, I am trying to trouble shoot my 1997 volvo Penta 5.7GSI throttle body injectors. i have one injector that works, and the other acts like it is stuck open and delivers to much fuel. If I unplug them and switch the plugs, the bad injector starts working properly, While the other one that did work correctly starts becoming faulty like the other.

Is there a relay, or sending unit that tells them when to open and close and how much other than the ecm?
 
No... controlled directly by ECM. The rate at which these open and close is so high that only direct electronic control will work.
 
Samuel JR said:
Hello, I am trying to trouble shoot my 1997 volvo Penta 5.7GSI throttle body injectors. i have one injector that works, and the other acts like it is stuck open and delivers to much fuel. If I unplug them and switch the plugs, the bad injector starts working properly, While the other one that did work correctly starts becoming faulty like the other.

Is there a relay, or sending unit that tells them when to open and close and how much other than the ecm?
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Did you ever get this fixed? I'm having the same problem on mine. Thank you
 
Since there are a few of you guys on this thread that have individual threads going on the same subject might as well keep it all here now. Has anyone checked their fuel pressure? Anyone run fuel system cleaner? Can everyone confirm that they have a fine mist cone of fuel coming out of their injectors? It should not look like a stream. Everyone running a high idle at cold start that drops as the engine temp warms?

I'm far from the best person to answer this, but these are common things you want to be looking for.
 
Chris Rohde said:
Since there are a few of you guys on this thread that have individual threads going on the same subject might as well keep it all here now. Has anyone checked their fuel pressure? Anyone run fuel system cleaner? Can everyone confirm that they have a fine mist cone of fuel coming out of their injectors? It should not look like a stream. Everyone running a high idle at cold start that drops as the engine temp warms?

I'm far from the best person to answer this, but these are common things you want to be looking for.
Click to expand...

My engine is always been rich at cold start with rough idling. I've done some parts chasing and it's still pretty consistent. Rich condition at cold start up with rough idling usually throttle up clears out then after warm up it becomes hard to start aka galloping.
 
Chris Rohde said:
Since there are a few of you guys on this thread that have individual threads going on the same subject might as well keep it all here now. Has anyone checked their fuel pressure? Anyone run fuel system cleaner? Can everyone confirm that they have a fine mist cone of fuel coming out of their injectors? It should not look like a stream. Everyone running a high idle at cold start that drops as the engine temp warms?

I'm far from the best person to answer this, but these are common things you want to be looking for.
Click to expand...

Yes all of this has been checked. Engine runs fine on ears. Put it in the water and on a load one injector sticks open. Switch the connectors and the other injector displays the same problem.
 
Anyone figure out what this issue is? Believe I am experiencing same issue. Smokes when starting, rough idle. Seems to smooth out at higher rpm. Higher fuel consumption when compared to sister engine. No power loss...
 
MrDelicious said:
Anyone figure out what this issue is? Believe I am experiencing same issue. Smokes when starting, rough idle. Seems to smooth out at higher rpm. Higher fuel consumption when compared to sister engine. No power loss...
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same engine? currently I have my TBI unit at a rebuilder, going to put shaft bushings in, clean and test injectors, new TPS and IAC. Hopefully it will take care of the problem, will keep posting.
 
Chris Rohde said:
Since there are a few of you guys on this thread that have individual threads going on the same subject might as well keep it all here now. Has anyone checked their fuel pressure? Anyone run fuel system cleaner? Can everyone confirm that they have a fine mist cone of fuel coming out of their injectors? It should not look like a stream. Everyone running a high idle at cold start that drops as the engine temp warms?

I'm far from the best person to answer this, but these are common things you want to be looking for.
Click to expand...
interestingly enough it does not idle high, 650 RPM normal. seems like that points to air mixture, not enough air to burn the excess fuel?
 
MrDelicious said:
Anyone figure out what this issue is? Believe I am experiencing same issue. Smokes when starting, rough idle. Seems to smooth out at higher rpm. Higher fuel consumption when compared to sister engine. No power loss...
Click to expand...
Your issue sounds a bit different than the ones above from 2017 and 2020…the ones above sort of sounds like maybe a injector driver circuit issue within the ECM… they might try a noid light and compare the flashing… the ECM may be repairable if that’s the case.

You @MrDelicious may have a bad MAP sensor… if you have 2 engines, you could try swapping the sensor/s to see if the issue follows.
 
kingsfisherman said:
I just remembered that after I would throttle up to burn off the excess fuel and return to idle, it would idle high and I would have to wiggle the throttle linkage to get it to idle down. then it would be good.
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I have rough running at idle. Smokes ( light) at idle Symptoms of a pcv valve issue , but that isn't issue. Seems like it's the throttle body injector issue from other online posts I've read. Higher fuel consumption vs sister motor. Otherwise it runs strong, for now, but there is obviously something wrong.
 
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