3.1 Fuel Injector testing/replacement - clarification and advice please
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3.1 Fuel Injector testing/replacement - clarification and advice please
1991 with a 3.1L V6.
OEM injectors with 145,000 on them
Symptoms: Stalled on me taking a right turn the other day, and has recently been acting up slightly for a few seconds when started - noticed a fuel odor and a puff of smoke from exhaust like it was flooded, and also noticed a temporary high idle for a few seconds. Would seem that maybe fuel is leaking down into cylinder(s)
Its not clear to me how to test the injector resistance - must it be done at the individual fuel injector directly under the intake?
Or can it be done at a 6 pin plug that I see located under the throttle body near the coolant temp sensor and thermostat housing?
The 6 pin plug I speak of seems to have 2 coolant temp sensor wires, and then 4 more that are pink/blue and green and one other color I don't recall at the moment but at any rate seemed to match the same exact colors I saw on the fuel injectors.
It appears to me that the 3 drivers side injectors had one set of 2 colors, then the passenger side 3 injectors had another set of two colors.
It seems to me that all 3 injectors on the drivers side all share the same color wires, then same scenario but 2 different colors on the passenger side
So I guess that would account for and give 6 total wires in the plug if I'm not missing something
When I pulled the 6 pin connector, I was getting 4.1ohms across 2 sets of the 6 pins which i assume would be the fuel injectors, and 475 ohms across 2 of the pins which would seem to be the temp sensor.
Engine was hot when checked.
Is this an accurate way of checking the resistance of the fuel injectors? or do you have to pull the top of the intake and release the wires and measure directly on the individual injector?
What other parts (like gaskets) will I need other than what I see here: southbayfuelinjectors ?
Anything else I should replace while I'm in there doing injectors? I think the fuel pressure regulator is in there as well? Does it make sense to do that while I'm in there?
OEM injectors with 145,000 on them
Symptoms: Stalled on me taking a right turn the other day, and has recently been acting up slightly for a few seconds when started - noticed a fuel odor and a puff of smoke from exhaust like it was flooded, and also noticed a temporary high idle for a few seconds. Would seem that maybe fuel is leaking down into cylinder(s)
Its not clear to me how to test the injector resistance - must it be done at the individual fuel injector directly under the intake?
Or can it be done at a 6 pin plug that I see located under the throttle body near the coolant temp sensor and thermostat housing?
The 6 pin plug I speak of seems to have 2 coolant temp sensor wires, and then 4 more that are pink/blue and green and one other color I don't recall at the moment but at any rate seemed to match the same exact colors I saw on the fuel injectors.
It appears to me that the 3 drivers side injectors had one set of 2 colors, then the passenger side 3 injectors had another set of two colors.
It seems to me that all 3 injectors on the drivers side all share the same color wires, then same scenario but 2 different colors on the passenger side
So I guess that would account for and give 6 total wires in the plug if I'm not missing something
When I pulled the 6 pin connector, I was getting 4.1ohms across 2 sets of the 6 pins which i assume would be the fuel injectors, and 475 ohms across 2 of the pins which would seem to be the temp sensor.
Engine was hot when checked.
Is this an accurate way of checking the resistance of the fuel injectors? or do you have to pull the top of the intake and release the wires and measure directly on the individual injector?
What other parts (like gaskets) will I need other than what I see here: southbayfuelinjectors ?
Anything else I should replace while I'm in there doing injectors? I think the fuel pressure regulator is in there as well? Does it make sense to do that while I'm in there?
Joined: Aug 2011
Posts: 661
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From: Texas
Car: 91 Firebird/88 Firebird/91 Formula
Engine: V6 3.1/V8 5.0/V8 5.0
Transmission: 4L60/700R4/4L60
Axle/Gears: 3.23/2.73/2.73
Re: 3.1 Fuel Injector testing/replacement - clarification and advice please
You're not the first with this kind of problem.
https://www.thirdgen.org/forums/tech...-out-soon.html
https://www.thirdgen.org/forums/tech...-out-soon.html
Joined: Mar 2017
Posts: 4,255
Likes: 427
From: Portland, OR
Car: 86 Imponte Ruiner 450GT, 91 Formula
Engine: 350 Vortec, FIRST TPI, 325 RWHP
Transmission: 700R4 3000 stall.
Axle/Gears: 9 Bolt Torsen 3.70
Re: 3.1 Fuel Injector testing/replacement - clarification and advice please
Check your coolant temp sensor.
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